---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Sun 03/29/09: 26 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:57 AM - Re: EI vs JPI (Richard Mutzman) 2. 11:42 AM - Re: Re: EI vs JPI (teamgrumman@AOL.COM) 3. 12:03 PM - Re: Re: EI vs JPI (Gil Alexander) 4. 05:40 PM - Re: Re: EI vs JPI (teamgrumman@AOL.COM) 5. 06:42 PM - Re: Re: EI vs JPI (Gil Alexander) 6. 07:04 PM - Re: Re: EI vs JPI (923te) 7. 07:14 PM - Re: Re: EI vs JPI (Gil Alexander) 8. 07:32 PM - Re: Re: EI vs JPI (923te) 9. 07:33 PM - Re: Re: EI vs JPI (923te) 10. 07:33 PM - Re: Re: EI vs JPI (923te) 11. 07:33 PM - Re: Re: EI vs JPI (923te) 12. 07:35 PM - Re: Re: EI vs JPI (flyv35b) 13. 07:46 PM - Re: Re: EI vs JPI (923te) 14. 07:46 PM - Re: Re: EI vs JPI (923te) 15. 07:51 PM - Re: Re: EI vs JPI (Gil Alexander) 16. 07:58 PM - Re: Re: EI vs JPI (Gil Alexander) 17. 08:02 PM - Re: Re: EI vs JPI (linn) 18. 08:04 PM - Re: Re: EI vs JPI (923te) 19. 08:04 PM - Re: Re: EI vs JPI (923te) 20. 08:13 PM - Re: Re: EI vs JPI (Gil Alexander) 21. 08:20 PM - Re: Re: EI vs JPI (923te) 22. 08:27 PM - Re: Re: EI vs JPI (Gil Alexander) 23. 08:32 PM - Re: Re: EI vs JPI (Gil Alexander) 24. 08:36 PM - Re: Re: EI vs JPI (923te) 25. 09:06 PM - Re: Re: EI vs JPI (Gil Alexander) 26. 09:22 PM - Re: Re: EI vs JPI (923te) ________________________________ Message 1 _____________________________________ Time: 06:57:35 AM PST US From: Richard Mutzman Subject: TeamGrumman-List: RE: EI vs JPI Gil=2C I tend to agree with what you are saying. It does appear that Lycoming use d the spring loaded type probe which touches the metal. Therefore it seems logical that if one uses a probe that touches the metal (whether EI or JPI and installed correctly=2C common or floating ground)=2C observes the temp limits of 500 and 400=2C one should be ok from a cylinder durability persp ective. At least from the temp side of the durability "equation". Thanks for dong the research on this. When I put in a CHT system=2C I will use the bayonet type probe=2C independent of JPI or EI electronics. Rich _________________________________________________________________ Hotmail=AE is up to 70% faster. Now good news travels really fast. http://windowslive.com/online/hotmail?ocid=TXT_TAGLM_WL_HM_70faster_03200 9 ________________________________ Message 2 _____________________________________ Time: 11:42:49 AM PST US Subject: Re: TeamGrumman-List: RE: EI vs JPI From: teamgrumman@AOL.COM This is only true if, and it's a big IF, the temperatures displayed on today s instrumentation "WOULD" have displayed the same temperatures as those reco rded by Lycoming technicians=C2-on the instrumentation used by Lycoming. =C2- I don't care what Lycoming's results were. =C2-I don't care what system Ly coming used, grounded or ungrounded, J or K type probes, etc., whenever it w as they did their testing. =C2-We don't even know if they tested to destru ction. =C2-OR. =C2-Did they just get out a metallurgy handbook and look at aluminum properties and pick a limit from there? =C2- There are so many 'old wives' tales regarding how to operate EGTs and CHTs a nd so many recommendations that contradict each other that I'm not convinced any of them are true. =C2-I would like to see Lycoming step up to the pla te and do their own testing and comparisons with todays instrumentation. =C2-Even if I had the same MIL spec probes Lycoming supposedly used, there is no guarantee that I'd see the same temperatures Lycoming did under the s ame conditions. =C2-THE ONLY THING I COULD BE SURE OF, using the exact sam e instrumentation Lycoming did, IS A VIABLE REASON FOR WARRANTEE WORK FROM L YCOMING should a cylinder fail. It is obvious, at least to me, that JPI and EI instrumentation give dramatic ally different temperature read-outs. =C2-Is it just the probe? =C2-Is i t the difference between grounded or ungrounded thermal couples? My personal upper CHT limit on climb out, on the JPI 800, i s 470 degrees. =C2-WHY? =C2-Because, under the same conditions, I saw 39 0-400 on the EI sitting next to my JPI (do back off on power at 440 and lowe r the nose to keep it below 450). =C2-My high power, 2700 rpm, cruise limi t is 425 (350 on an EI). =C2-I expect to see something in the neighborhood of 380 degrees (320 on an EI) at 65% power and 8500 feet. =C2- Speaking of 'old wives' tales: =C2-Why do we have such strict limitations on tear-down and inspection if an engine is operated over 2700 rpm? =C2-Wh ere did the 2700 rpm limit come from? =C2-Why is there a 2700 rpm limit on airplane engines and a 2900 to 3200 rpm limit on similar engines used in he licopters? =C2- -----Original Message----- From: Richard Mutzman Sent: Sun, 29 Mar 2009 6:56 am Subject: TeamGrumman-List: RE: EI vs JPI Gil, =C2- I tend to agree with what you are saying.=C2- It does=C2-appear that Lyc oming used the spring loaded type probe which touches the metal.=C2- There fore it seems logical that if one uses a probe that touches the metal (wheth er EI or JPI and installed correctly, common or floating ground), observes t he temp limits of 500 and 400, one should be ok from a cylinder durability p erspective.=C2- At least from the temp side of the durability "equation". =C2- =C2- Thanks for dong the research on this.=C2- When I put in a CHT system, I wi ll use the bayonet type probe, independe nt of JPI or EI electronics. Rich Hotmail=C2=AE is up to 70% faster. Now good news travels really fast. Find o ut more. ________________________________ Message 3 _____________________________________ Time: 12:03:55 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI >This is only true if, and it's a big IF, the >temperatures displayed on todays instrumentation >"WOULD" have displayed the same temperatures as >those recorded by Lycoming technicians=C2 on the >instrumentation used by Lycoming. =C2 Gary... I don't belief that is a big "IF"... The electrical characteristics of a type J thermocouple have been well known from long before WWII. The electrical instrumentation bit has not changed over the years as far as the basic thermocouple, especially when used in an engine test cell. I bet Lycoming had individual CHT meters directly connected to the probes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a type J thermocouple has always created the same amount of voltage due to physics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues. You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change. Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs... gil A ITS-90 Table for type J thermocouple =B0C 0 1 2 3 4 5 6 7 8 9 10 Thermoelectric Voltage in mV 0 0.000 0.050 0.101 0.151 0.202 0.253 0.303 0.354 0.405 0.456 0.507 10 0.507 0.558 0.609 0.660 0.711 0.762 0.814 0.865 0.916 0.968 1.019 20 1.019 1.071 1.122 1.174 1.226 1.277 1.329 1.381 1.433 1.485 1.537 30 1.537 1.589 1.641 1.693 1.745 1.797 1.849 1.902 1.954 2.006 2.059 40 2.059 2.111 2.164 2.216 2.269 2.322 2.374 2.427 2.480 2.532 2.585 50 2.585 2.638 2.691 2.744 2.797 2.850 2.903 2.956 3.009 3.062 3.116 60 3.116 3.169 3.222 3.275 3.329 3.382 3.436 3.489 3.543 3.596 3.650 70 3.650 3.703 3.757 3.810 3.864 3.918 3.971 4.025 4.079 4.133 4.187 80 4.187 4.240 4.294 4.348 4.402 4.456 4.510 4.564 4.618 4.672 4.726 90 4.726 4.781 4.835 4.889 4.943 4.997 5.052 5.106 5.160 5.215 5.269 100 5.269 5.323 5.378 5.432 5.487 5.541 5.595 5.650 5.705 5.759 5.814 110 5.814 5.868 5.923 5.977 6.032 6.087 6.141 6.196 6.251 6.306 6.360 120 6.360 6.415 6.470 6.525 6.579 6.634 6.689 6.744 6.799 6.854 6.909 130 6.909 6.964 7.019 7.074 7.129 7.184 7.239 7.294 7.349 7.404 7.459 140 7.459 7.514 7.569 7.624 7.679 7.734 7.789 7.844 7.900 7.955 8.010 150 8.010 8.065 8.120 8.175 8.231 8.286 8.341 8.396 8.452 8.507 8.562 160 8.562 8.618 8.673 8.728 8.783 8.839 8.894 8.949 9.005 9.060 9.115 170 9.115 9.171 9.226 9.282 9.337 9.392 9.448 9.503 9.559 9.614 9.669 180 9.669 9.725 9.780 9.836 9.891 9.947 10.002 10.057 10.113 10.168 10.224 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16.216 16.272 16.327 ________________________________ Message 4 _____________________________________ Time: 05:40:36 PM PST US Subject: Re: TeamGrumman-List: RE: EI vs JPI From: teamgrumman@AOL.COM There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2- MY PLANE? =C2-Ok, maybe your right. =C2-The grounds in installed accordi ng to the STC were done wrong. =C2-Maybe the probes grounding against bran d new cylinders had corrosion built up in them. =C2- Maybe planes experiencing CHT readings higher on a JPI than on an EI also fo llowed the installation instructions. How about you doing your own testing and report your own results? -----Original Message----- From: Gil Alexander Sent: Sun, 29 Mar 2009 12:03 pm Subject: Re: TeamGrumman-List: RE: EI vs JPI This is only true if, and it's a big IF, the temperatures displayed on todays instrumentation "WOULD" have displayed the same temperatures as those recorded by Lycoming technicians=C3=82 on the instrumentation used by Lycoming. =C3 =82=C2- Gary... I don't belief that is a big "IF"... The electrical characteristics of a type J thermocouple have been well known from long before WWII. The electrical instrumentation bit has not changed over the years as far as the basic thermocouple, especially when used in an engine test cell.=C2- I bet Lycoming had individual CHT meters directly connected to the probes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a type J therm ocouple has always created the same amount of voltage due to physics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2- You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change.=C2- Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs...=C2- gil A =C2-ITS-90 Table for type J=C2- thermocouple =C2-=C2=B0C=C2-=C2-=C2-=C2-=C2- 0=C2-=C2-=C2-=C2-=C2- 1=C2-=C2-=C2-=C2-=C2- 2=C2-=C2-=C2-=C2-=C2- 3=C2-=C2-=C2-=C2-=C2- 4=C2-=C2-=C2-=C2-=C2- 5=C2-=C2-=C2-=C2-=C2- 6=C2-=C2-=C2-=C2-=C2- 7=C2-=C2-=C2-=C2-=C2- 8=C2-=C2-=C2-=C2-=C2- 9=C2-=C2-=C2-=C2- 10 =C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2 -=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2-=C2- =C2-=C2-=C2-=C2-=C2- Thermoelectric Voltage in mV =C2- =C2-=C2- 0=C2- 0.000=C2- 0.050=C2- 0.101=C2- 0.151=C2- 0.202=C2- 0.253=C2- 0.303=C2- 0.354=C2- 0.405=C2- 0.456=C2- 0.507 =C2- 10=C2- 0.507=C2- 0.558=C2- 0.609=C2- 0.660=C2- 0.711=C2- 0.762=C2- 0.814=C2- 0.865=C2- 0.916=C2- 0.968=C2- 1.019 =C2- 20=C2- 1.019=C2- 1.071=C2- 1.122=C2- 1.174=C2- 1.226=C2- 1.277=C2- 1.329=C2- 1.381=C2- 1.433=C2- 1.485=C2- 1.537 =C2- 30=C2- 1.537=C2- 1.589=C2- 1.641=C2- 1.693=C2- 1.745=C2- 1.797=C2- 1.849=C2- 1.902=C2- 1.954=C2- 2.006=C2- 2.059 =C2- 40=C2- 2.059=C2- 2.111=C2- 2.164=C2- 2.216A 0 2.269=C2- 2.322=C2- 2.374=C2- 2.427=C2- 2.480=C2- 2.532=C2- 2.585 =C2- =C2- 50=C2- 2.585=C2- 2.638=C2- 2.691=C2- 2.744=C2- 2.797=C2- 2.850=C2- 2.903=C2- 2.956=C2- 3.009=C2- 3.062=C2- 3.116 =C2- 60=C2- 3.116=C2- 3.169=C2- 3.222=C2- 3.275=C2- 3.329=C2- 3.382=C2- 3.436=C2- 3.489=C2- 3.543=C2- 3.596=C2- 3.650 =C2- 70=C2- 3.650=C2- 3.703=C2- 3.757=C2- 3.810=C2- 3.864=C2- 3.918=C2- 3.971=C2- 4.025=C2- 4.079=C2- 4.133=C2- 4.187 =C2- 80=C2- 4.187=C2- 4.240=C2- 4.294=C2- 4.348=C2- 4.402=C2- 4.456=C2- 4.510=C2- 4.564=C2- 4.618=C2- 4.672=C2- 4.726 =C2- 90=C2- 4.726=C2- 4.781=C2- 4.835=C2- 4.889=C2- 4.943=C2- 4.997=C2- 5.052=C2- 5.106=C2- 5.160=C2- 5.215=C2- 5.269 =C2- =C2-100=C2- 5.269=C2- 5.323=C2- 5.378=C2- 5.432=C2- 5.487=C2- 5.541=C2- 5.595=C2- 5.650=C2- 5.705=C2- 5.759=C2- 5.814 =C2-110=C2- 5.814=C2- 5.868=C2- 5.923=C2- 5.977=C2- 6.032=C2- 6.087=C2- 6.141=C2- 6.196=C2- 6.251=C2- 6.306=C2- 6.360 =C2-120=C2- 6.360=C2- 6.415=C2- 6.470=C2- 6.525=C2- 6.579=C2- 6.634=C2- 6.689=C2- 6.744=C2- 6.799=C2- 6.854=C2- 6.909 =C2-130=C2- 6.909=C2- 6.964=C2- 7.019=C2- 7.074=C2- 7.129=C2- 7.184=C2- 7.239=C2- 7.294=C2- 7.349=C2- 7.404=C2- 7.459 =C2-140=C2- 7.459=C2- 7.514=C2- 7.569=C2- 7.624=C2- 7.679=C2- 7.734=C2- 7.789=C2- 7.844=C2- 7.900=C2- 7.955=C2- 8.010 =C2- =C2-150=C2- 8.010=C2- 8.065=C2- 8.120=C2- 8.175=C2- 8.231=C2- 8.286=C2- 8.341=C2- 8.396=C2- 8.452=C2- 8.507=C2- 8.562 =C2-160=C2- 8.562=C2- 8.618=C2- 8.673C2 8.728=C2- 8.783=C2- 8.839=C2- 8.894=C2- 8.949=C2- 9.005=C2- 9.060=C2- 9.115 =C2-170=C2- 9.115=C2- 9.171=C2- 9.226=C2- 9.282=C2- 9.337=C2- 9.392=C2- 9.448=C2- 9.503=C2- 9.559=C2- 9.614=C2- 9.669 =C2-180=C2- 9.669=C2- 9.725=C2- 9.780=C2- 9.836=C2- 9.891=C2- 9.947 10.002 10.057 10.113 10.168 10.224 =C2-190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 =C2- =C2-200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 =C2-210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 =C2-220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 =C2-230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 =C2-240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 =C2- =C2-250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 =C2-260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 =C2-270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 =C2-280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 =C2-290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16.216 16.272 16.327 vigator to browse ________________________________ Message 5 _____________________________________ Time: 06:42:59 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI Gary, How many STCs have you installed with poor/bad/wrong instructions? And the CHT/EGT monitor STCs are quite "generic" not really airframe specific. My latest one was my Plane Power voltage regulator. Works fine, but needed spacers to clear the "bumps" on the fire wall - hardly a drop-in exact replacement for the non flat bottom mechanical regulator - and no mention in the STC instructions. Your plane seems to be the only test case reporting the problem. I'm happy with the Insight GEM in mine with it's probes that touch the thermowell bottom like I believe the Lycoming test bayonet probes did during their certification. As an electronics engineer, I know I would not design sensitive millivolts equipment using grounded sensors.... but that's just me.... and my stuff is (or has been) working in military aircraft and space vehicles....:^) gil A PS ...I like the GEM unit, but I have the "bars only" version - I would prefer the version with numbers - a probable future upgrade. PPS Sorry about the formatting of the mV chart in my previous e-mail Here is an alternate link to another table of National Institute of Standards and Technology output voltages from a Type J thermocouple - http://www.omega.com/temperature/Z/pdf/z203.pdf This shows how small the DC voltages are that we are measuring. At 05:40 PM 3/29/2009, you wrote: >There is something else going on here in your >plane - and since we are dealing with fractions >of milliVolts, I would personally vote for grounding issues.=C2 > >MY PLANE? =C2 Ok, maybe your right. =C2 The grounds >in installed according to the STC were done >wrong. =C2 Maybe the probes grounding against >brand new cylinders had corrosion built up in them. =C2 > >Maybe planes experiencing CHT readings higher on >a JPI than on an EI also followed the installation instructions. > >How about you doing your own testing and report your own results? > > >-----Original Message----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sun, 29 Mar 2009 12:03 pm >Subject: Re: TeamGrumman-List: RE: EI vs JPI > > >>This is only true if, and it's a big IF, the >>temperatures displayed on todays >>instrumentation "WOULD" have displayed the same >>temperatures as those recorded by Lycoming >>technicians=C3=82 on the instrumentation used by Lycoming. =C3=82=C2 > >Gary... I don't belief that is a big "IF"... > >The electrical characteristics of a type J >thermocouple have been well known from long before WWII. > >The electrical instrumentation bit has not >changed over the years as far as the basic >thermocouple, especially when used in an engine >test cell.=C2 I bet Lycoming had individual CHT >meters directly connected to the probes, none of >this fancy digital switching, scanning stuff....:^) > >Today the probes and the interconnect may be >different, but the a type J thermocouple has >always created the same amount of voltage due to physics. > >There is something else going on here in your >plane - and since we are dealing with fractions >of milliVolts, I would personally vote for >grounding issues.=C2 You can see from the table >below that 10 degrees Centigrade is about a 1/2 >milliVolt change.=C2 Try a direct wire from GND on your EI gauge to the engine. > >This is from Sandia labs...=C2 gil A > > >=C2 ITS-90 Table for type J=C2 thermocouple >=C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 >1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 >3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 >5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 >7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 >9=C2 =C2 =C2 =C2 10 >=C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 >Thermoelectric Voltage in mV >=C2 >=C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 >0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 >0.507 >=C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 >0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 >1.019 >=C2 20=C2 1.019=C2 1.071 > 1.122=C2 1.174=C2 >1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 >1.537 >=C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 >1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 >2.059 >=C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 >2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 >2.585 >=C2 >=C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 >2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 >3.116 >=C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 >3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 >3.650 >=C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 >3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 >4.187 >=C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 >4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 >4.726 >=C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 >4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 >5.269 >=C2 >=C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 >5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 >5.814 >=C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 >6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 >6.360 >=C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 >6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 >6.909 >=C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 >7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 >7.459 >=C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 >7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 >8.010 >=C2 >=C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 >8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 >8.562 >=C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 >8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 >9.115 >=C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 >9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 >9.669 >=C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 >9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 >=C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 >10.723 10.779 >=C2 >=C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 >11.278 11.334 >=C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 >11.834 11.889 >=C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 >12.389 12.445 >=C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 >12.944 13.000 >=C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 >13.500 13.555 >=C2 >=C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 >14.055 14.110 >=C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 >14.609 14.665 >=C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 >15.164 15.219 >=C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 >15.718 15.773 >=C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. >216 >16.272 16.327 > > >or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List >p://forums.matronics.com >ution">http://www.matronics.com/contribution >======================== > > >---------- >A Good Credit Score is 700 or Above. http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D668072%26hmpg ID%3D62%26bcd%3DfebemailfooterNO62>See >yours in just 2 easy steps! > ________________________________ Message 6 _____________________________________ Time: 07:04:12 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI I started this thread because of similar thread that was started on the GG. I understood one poster to say that he too had experienced higher readings with JPI type probes that actually touch the thermowell. He had both in his Cheetah and found that the probes that touch the head actually give a higher reading. So in answer to Gil's post it appears that others have noted the diffenece in temp readings besides Gary. Someone at Lycoming needs to answer this question, at least the question of the type of probe they used. Right now we are just speculating on what type of probe they used. Ned Here is the post I refer to: ----- Original Message ----- From: John Horton Sent: Tuesday, March 24, 2009 9:19 PM Subject: RE: Tiger outlet ramps - More Info Req. Dave, I would direct you to look at http://www.bondline.org/wiki/Lower_Cowling_Split for info about reworking the exit ramps. That link will only provide info about the metal exit ramps but that's half the options. When you mention that your temps are "warm" be sure to review the GG archives about JPI instrumentation vs EI instrumentation. There are differences in probe design that make JPI read higher that EI in what should be the same cylinder. So if you have JP CHT and think your running "warm" you might be just fine if you had EI CHT. Theres a good bit of reading in the archives on that topic. My consensus after reviewing (and I might still have it wrong) is that JP CHT reads hotter than EI due to the fact that the JP CHT probe actually is spring loaded to touch the cyl head. The EI CHT probe screws into a space in the cyl head. I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter. So if you have JP CHT gauge and it reads 420 in climb your most likely fine. (Assuming the temp goes down when you level out) The same plane may well read 385 with a EI CHT and it is fine also. Be sure to know your temp source (EI or JP) and read the archives to get a feel for the differences before you go and rework your exit ramps. They might be fine. I recently reworked my exit ramps on my Cheetah due to a "warmer" than I'd like #4 cyl, cracks in my metal exit ramps and a newly minted A&P ticket that allowed me to do it. I have only flown it once and the results looked promising. Tommorrow I hope to gather more flight data. I currently have a JP CHT/EGT and in climb prior to the ramp work could occasionally hit 450 (my and Lycomings redline). I could easily get into the 430's in climb and have to nose over and or throttle back to arrest the CHT rise. When I had the EI CHT gauge I never saw anything above 390. After reworking the ramps I do expect to go faster, climb higher and do it all with 1/3 flaps deployed for less gallons per hour. I just had to throw that in in case there aren't enough emotionally loaded topics to write about. John Horton HC Cheetah Sensenich Prop ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 8:41 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Gary, How many STCs have you installed with poor/bad/wrong instructions? And the CHT/EGT monitor STCs are quite "generic" not really airframe specific. My latest one was my Plane Power voltage regulator. Works fine, but needed spacers to clear the "bumps" on the fire wall - hardly a drop-in exact replacement for the non flat bottom mechanical regulator - and no mention in the STC instructions. Your plane seems to be the only test case reporting the problem. I'm happy with the Insight GEM in mine with it's probes that touch the thermowell bottom like I believe the Lycoming test bayonet probes did during their certification. As an electronics engineer, I know I would not design sensitive millivolts equipment using grounded sensors.... but that's just me.... and my stuff is (or has been) working in military aircraft and space vehicles....:^) gil A PS ...I like the GEM unit, but I have the "bars only" version - I would prefer the version with numbers - a probable future upgrade. PPS Sorry about the formatting of the mV chart in my previous e-mail Here is an alternate link to another table of National Institute of Standards and Technology output voltages from a Type J thermocouple - http://www.omega.com/temperature/Z/pdf/z203.pdf This shows how small the DC voltages are that we are measuring. At 05:40 PM 3/29/2009, you wrote: There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 MY PLANE? =C2 Ok, maybe your right. =C2 The grounds in installed according to the STC were done wrong. =C2 Maybe the probes grounding against brand new cylinders had corrosion built up in them. =C2 Maybe planes experiencing CHT readings higher on a JPI than on an EI also followed the installation instructions. How about you doing your own testing and report your own results? -----Original Message----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sun, 29 Mar 2009 12:03 pm Subject: Re: TeamGrumman-List: RE: EI vs JPI This is only true if, and it's a big IF, the temperatures displayed on todays instrumentation "WOULD" have displayed the same temperatures as those recorded by Lycoming technicians=C3, on the instrumentation used by Lycoming. =C3,=C2 Gary... I don't belief that is a big "IF"... The electrical characteristics of a type J thermocouple have been well known from long before WWII. The electrical instrumentation bit has not changed over the years as far as the basic thermocouple, especially when used in an engine test cell.=C2 I bet Lycoming had individual CHT meters directly connected to the probes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a type J thermocouple has always created the same amount of voltage due to physics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change.=C2 Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs...=C2 gil A =C2 ITS-90 Table for type J=C2 thermocouple =C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 9=C2 =C2 =C2 =C2 10 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 Thermoelectric Voltage in mV =C2 =C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 0.507 =C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 1.019 =C2 20=C2 1.019=C2 1.071 1.122=C2 1.174=C2 1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 1.537 =C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 2.059 =C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 2.585 =C2 =C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 3.116 =C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 3.650 =C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 4.187 =C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 4.726 =C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 5.269 =C2 =C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 5.814 =C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 6.360 =C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 6.909 =C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 7.459 =C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 8.010 =C2 =C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 8.562 =C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 9.115 =C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 9.669 =C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 =C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 =C2 =C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 =C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 =C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 =C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 =C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 =C2 =C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 =C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 =C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 =C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 =C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. 216 16.272 16.327 or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List p://forums.matronics.com ution">http://www.matronics.com/contribution ------------------------------------------------------------------------- --- A Good Credit Score is 700 or Above. ?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D6 68072%26hmpgID%3D62%26bcd%3DfebemailfooterNO62"> See yours in just 2 easy steps! ________________________________ Message 7 _____________________________________ Time: 07:14:05 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A At 07:05 PM 3/29/2009, you wrote: >I started this thread because of similar thread >that was started on the GG. I understood one >poster to say that he too had experienced higher >readings with JPI type probes that actually >touch the thermowell. He had both in his Cheetah >and found that the probes that touch the head actually give a higher reading. > >So in answer to Gil's post it appears that >others have noted the diffenece in temp readings besides Gary. > >Someone at Lycoming needs to answer this >question, at least the question of the type of >probe they used. Right now we are just >speculating on what type of probe they used. > >Ned > >Here is the post I refer to: > > >----- Original Message ----- >From: John Horton >To: 'Dave Kalwick' >; 'GG' >Sent: Tuesday, March 24, 2009 9:19 PM >Subject: RE: Tiger outlet ramps - More Info Req. > >Dave, >I would direct you to look at >http://www.bondline.org/w iki/Lower_Cowling_Split >for info about reworking the exit ramps. That link will only provide info >about >the metal exit ramps but that's half the options. > >When you mention that your temps are "warm" be sure to review the GG archives >about JPI instrumentation vs EI instrumentation. There are differences in >probe >design that make JPI read higher that EI in what should be the same cylinder. >So if you have JP CHT and think your running "warm" you might be just fine if >you had EI CHT. Theres a good bit of reading in the archives on that topic. >My >consensus after reviewing (and I might still have it wrong) is that JP CHT >reads >hotter than EI due to the fact that the JP CHT probe actually is spring >loaded >to touch the cyl head. The EI CHT probe screws into a space in the cyl head. >I >have had both in my plane (Cheetah) and can verify that fact. The probes are >different and the JP touches the head and reads hotter. > >So if you have JP CHT gauge and it reads 420 in climb your most likely fine. >(Assuming the temp goes down when you level out) The same plane may well read >385 with a EI CHT and it is fine also. Be sure to know your temp source (EI >or >JP) and read the archives to get a feel for the differences before you go and >rework your exit ramps. They might be fine. > >I recently reworked my exit ramps on my Cheetah due to a "warmer" than I'd >like >#4 cyl, cracks in my metal exit ramps and a newly minted A&P ticket that >allowed >me to do it. I have only flown it once and the results looked promising. >Tommorrow I hope to gather more flight data. I currently have a JP CHT/EGT >and >in climb prior to the ramp work could occasionally hit 450 (my and Lycomings >redline). I could easily get into the 430's in climb and have to nose over >and >or throttle back to arrest the CHT rise. When I had the EI CHT gauge I never >saw anything above 390. > >After reworking the ramps I do expect to go faster, climb higher and do it >all >with 1/3 flaps deployed for less gallons per hour. I just had to throw that >in >in case there aren't enough emotionally loaded topics to write about. > >John Horton >HC Cheetah >Sensenich Prop > ----- Original Message ----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sunday, March 29, 2009 8:41 PM >Subject: Re: TeamGrumman-List: RE: EI vs JPI > >Gary, > >How many STCs have you installed with >poor/bad/wrong instructions? And the CHT/EGT >monitor STCs are quite "generic" not really airframe specific. > >My latest one was my Plane Power voltage >regulator. Works fine, but needed spacers to >clear the "bumps" on the fire wall - hardly a >drop-in exact replacement for the non flat >bottom mechanical regulator - and no mention in the STC instructions. > >Your plane seems to be the only test case >reporting the problem. I'm happy with the >Insight GEM in mine with it's probes that touch >the thermowell bottom like I believe the >Lycoming test bayonet probes did during their certification. > >As an electronics engineer, I know I would not >design sensitive millivolts equipment using >grounded sensors.... but that's just me.... and >my stuff is (or has been) working in military >aircraft and space vehicles....:^) > >gil A > >PS ...I like the GEM unit, but I have the "bars >only" version - I would prefer the version with >numbers - a probable future upgrade. > >PPS Sorry about the formatting of the mV chart in my previous e-mail > >Here is an alternate link to another table of >National Institute of Standards and Technology >output voltages from a Type J thermocouple - > >http://www.omega.com/temperature/Z/pdf/z203.pdf > >This shows how small the DC voltages are that we are measuring. > >At 05:40 PM 3/29/2009, you wrote: >>There is something else going on here in your >>plane - and since we are dealing with fractions >>of milliVolts, I would personally vote for grounding issues.=C2 >> >>MY PLANE? =C2 Ok, maybe your right. =C2 The grounds >>in installed according to the STC were done >>wrong. =C2 Maybe the probes grounding against >>brand new cylinders had corrosion built up in them. =C2 >> >>Maybe planes experiencing CHT readings higher >>on a JPI than on an EI also followed the installation instructions. >> >>How about you doing your own testing and report your own results? >> >> >>-----Original Message----- >>From: Gil Alexander >>To: teamgrumman-list@matronics.com >>Sent: Sun, 29 Mar 2009 12:03 pm >>Subject: Re: TeamGrumman-List: RE: EI vs JPI >> >> >>>This is only true if, and it's a big IF, the >>>temperatures displayed on todays >>>instrumentation "WOULD" have displayed the >>>same temperatures as those recorded by >>>Lycoming technicians=C3=82 on the instrumentation used by Lycoming. =C3 =82=C2 >> >>Gary... I don't belief that is a big "IF"... >> >>The electrical characteristics of a type J >>thermocouple have been well known from long before WWII. >> >>The electrical instrumentation bit has not >>changed over the years as far as the basic >>thermocouple, especially when used in an engine >>test cell.=C2 I bet Lycoming had individual CHT >>meters directly connected to the probes, none >>of this fancy digital switching, scanning stuff....:^) >> >>Today the probes and the interconnect may be >>different, but the a type J thermocouple has >>always created the same amount of voltage due to physics. >> >>There is something else going on here in your >>plane - and since we are dealing with fractions >>of milliVolts, I would personally vote for >>grounding issues.=C2 You can see from the table >>below that 10 degrees Centigrade is about a 1/2 >>milliVolt change.=C2 Try a direct wire from GND on your EI gauge to the engine. >> >>This is from Sandia labs...=C2 gil A >> >> >> >> >>=C2 ITS-90 Table for type J=C2 thermocouple >> >>=C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 >> >>1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 >> >>3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 >> >>5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 >> >>7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 >> >>9=C2 =C2 =C2 =C2 10 >> >>=C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 >> >>Thermoelectric Voltage in mV >> >>=C2 >> >>=C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 >> >>0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 >> >>0.507 >> >>=C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 >> >>0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 >> >>1.019 >> >>=C2 20=C2 1.019=C2 1.071 >> >> 1.122=C2 1.174=C2 >> >>1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 >> >>1.537 >> >>=C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 >> >>1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 >> >>2.059 >> >>=C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 >> >>2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 >> >>2.585 >> >>=C2 >> >>=C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 >> >>2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 >> >>3.116 >> >>=C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 >> >>3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 >> >>3.650 >> >>=C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 >> >>3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 >> >>4.187 >> >>=C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 >> >>4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 >> >>4.726 >> >>=C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 >> >>4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 >> >>5.269 >> >>=C2 >> >>=C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 >> >>5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 >> >>5.814 >> >>=C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 >> >>6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 >> >>6.360 >> >>=C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 >> >>6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 >> >>6.909 >> >>=C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 >> >>7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 >> >>7.459 >> >>=C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 >> >>7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 >> >>8.010 >> >>=C2 >> >>=C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 >> >>8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 >> >>8.562 >> >>=C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 >> >>8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 >> >>9.115 >> >>=C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 >> >>9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 >> >>9.669 >> >>=C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 >> >>9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 >> >>=C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 >> >>10.723 10.779 >> >>=C2 >> >>=C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 >> >>11.278 11.334 >> >>=C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 >> >>11.834 11.889 >> >>=C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 >> >>12.389 12.445 >> >>=C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 >> >>12.944 13.000 >> >>=C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 >> >>13.500 13.555 >> >>=C2 >> >>=C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 >> >>14.055 14.110 >> >>=C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 >> >>14.609 14.665 >> >>=C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 >> >>15.164 15.219 >> >>=C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 >> >>15.718 15.773 >> >>=C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. >> >>216 >> >>16.272 16.327 >> >> >> >> >> >> >> >> >> >>or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List >> >>p://forums.matronics.com >> >>ution">http://www.matronics.com/contribution >> >> >> >> >>---------- >>A Good Credit Score is 700 or Above. >>?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D66 8072%26hmpgID%3D62%26bcd%3DfebemailfooterNO62"> >>See yours in just 2 easy steps! > > >href="http://www.matronics.com/Navigator?TeamGrumman-List">http://www.mat ronics.com/Navigator?TeamGrumman-List > >href="http://forums.matronics.com">http://forums.matronics.com > >href="http://www.matronics.com/contribution">http://www.matronics.com/c > ________________________________ Message 8 _____________________________________ Time: 07:32:58 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Here is another example given on the GG of others that have found the same as Gary. a.. Subject: Re: JPI vs EI probes b.. From: c.. Date: Wed, 09 Jan 2008 15:59:45 -0500 ------------------------------------------------------------------------- ----- Had I not had 200 hours on my Tiger with the JPI and KNOWN that the #3 cylinder was within a few degrees of cylinder #4, I would have to agree. B Yes, had I not had previous experience with my engine and the JPI, and yes IF I installed the EI into an unknown condition, then yes, one could say that one cylinder runs 80 degrees cooler than the others. But, that is not the case. For what it's worth, the testing on the new cowling is being done with EI gauges, calibrated by EI for the FAA. These probes are calibrated to read within 1 degree. These also show, on the average, on ALL 4 CYLINDERS, 50 to 80 degrees cooler than the data downloaded from the JPI. Different plane. B Different engine. Different baffles. And 50 to 80 degrees difference in temps. I talked to JPI. Their probes and analyzers are calibrated to within 1 degree. Mount a JPI CHT probe in a piece of steel 4 inches thick simulating the mounting in a cylinder. Mount the EI gauge in a hole in the steel. Heat the other side with a torch. You'll get different readings. LyCon has a customer in Wyoming (Wildoming) with a Husky. He changed from EI to JPI after and engine overhaul. He chased around 70 degree higher temps for a long time. And by chasing, I mean they pulled the engine and sent it back to LyCon for inspection. LyCon ran the engine without baffles and it was never over 380. They concluded the JPI must read higher. I had talked to Ken in the past about doing a side-by-side test of JPI and EI. Never done. We talked when his customer sent the engine back. I installed a JPI 700 in a Comanche following an engine overhaul. The engine overhaul was a complete firewall forward with all new baffles and seals. The owner complained of temps going over 450 on climb-out. I couldn't convince him it was the analyzer and not his engine. I just heard that he recently had the EI re-installed. He couldn't deal with seeing the temps going over 450 on climb-out. He told me that he now sees temps in the 380 range and he likes that better. Both readings of temperature are correct. They are measuring different temperatures. One measures the temp of the air in the well, the other measures the temperature of the aluminum. ________________________________ Message 9 _____________________________________ Time: 07:33:05 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Gil, I'm confused by your post below. Don't you mean for Gary to try a direct wire from GND on you JPI gauge to the engine? As EI are not grounded probes.... ned There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues. You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change. Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs... gil A ________________________________ Message 10 ____________________________________ Time: 07:33:08 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Perhaps there was a milspec probe like the one EI uses today in use on Lycomings certification tests... Like Isaid earlier we are just speculating ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A At 07:05 PM 3/29/2009, you wrote: I started this thread because of similar thread that was started on the GG. I understood one poster to say that he too had experienced higher readings with JPI type probes that actually touch the thermowell. He had both in his Cheetah and found that the probes that touch the head actually give a higher reading. So in answer to Gil's post it appears that others have noted the diffenece in temp readings besides Gary. Someone at Lycoming needs to answer this question, at least the question of the type of probe they used. Right now we are just speculating on what type of probe they used. Ned Here is the post I refer to: ----- Original Message ----- From: John Horton To: 'Dave Kalwick' ; 'GG' Sent: Tuesday, March 24, 2009 9:19 PM Subject: RE: Tiger outlet ramps - More Info Req. Dave, I would direct you to look at http://www.bondline.org/wiki/Lower_Cowling_Split for info about reworking the exit ramps. That link will only provide info about the metal exit ramps but that's half the options. When you mention that your temps are "warm" be sure to review the GG archives about JPI instrumentation vs EI instrumentation. There are differences in probe design that make JPI read higher that EI in what should be the same cylinder. So if you have JP CHT and think your running "warm" you might be just fine if you had EI CHT. Theres a good bit of reading in the archives on that topic. My consensus after reviewing (and I might still have it wrong) is that JP CHT reads hotter than EI due to the fact that the JP CHT probe actually is spring loaded to touch the cyl head. The EI CHT probe screws into a space in the cyl head. I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter. So if you have JP CHT gauge and it reads 420 in climb your most likely fine. (Assuming the temp goes down when you level out) The same plane may well read 385 with a EI CHT and it is fine also. Be sure to know your temp source (EI or JP) and read the archives to get a feel for the differences before you go and rework your exit ramps. They might be fine. I recently reworked my exit ramps on my Cheetah due to a "warmer" than I'd like #4 cyl, cracks in my metal exit ramps and a newly minted A&P ticket that allowed me to do it. I have only flown it once and the results looked promising. Tommorrow I hope to gather more flight data. I currently have a JP CHT/EGT and in climb prior to the ramp work could occasionally hit 450 (my and Lycomings redline). I could easily get into the 430's in climb and have to nose over and or throttle back to arrest the CHT rise. When I had the EI CHT gauge I never saw anything above 390. After reworking the ramps I do expect to go faster, climb higher and do it all with 1/3 flaps deployed for less gallons per hour. I just had to throw that in in case there aren't enough emotionally loaded topics to write about. John Horton HC Cheetah Sensenich Prop ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 8:41 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Gary, How many STCs have you installed with poor/bad/wrong instructions? And the CHT/EGT monitor STCs are quite "generic" not really airframe specific. My latest one was my Plane Power voltage regulator. Works fine, but needed spacers to clear the "bumps" on the fire wall - hardly a drop-in exact replacement for the non flat bottom mechanical regulator - and no mention in the STC instructions. Your plane seems to be the only test case reporting the problem. I'm happy with the Insight GEM in mine with it's probes that touch the thermowell bottom like I believe the Lycoming test bayonet probes did during their certification. As an electronics engineer, I know I would not design sensitive millivolts equipment using grounded sensors.... but that's just me.... and my stuff is (or has been) working in military aircraft and space vehicles....:^) gil A PS ...I like the GEM unit, but I have the "bars only" version - I would prefer the version with numbers - a probable future upgrade. PPS Sorry about the formatting of the mV chart in my previous e-mail Here is an alternate link to another table of National Institute of Standards and Technology output voltages from a Type J thermocouple - http://www.omega.com/temperature/Z/pdf/z203.pdf This shows how small the DC voltages are that we are measuring. At 05:40 PM 3/29/2009, you wrote: There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 MY PLANE? =C2 Ok, maybe your right. =C2 The grounds in installed according to the STC were done wrong. =C2 Maybe the probes grounding against brand new cylinders had corrosion built up in them. =C2 Maybe planes experiencing CHT readings higher on a JPI than on an EI also followed the installation instructions. How about you doing your own testing and report your own results? -----Original Message----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sun, 29 Mar 2009 12:03 pm Subject: Re: TeamGrumman-List: RE: EI vs JPI This is only true if, and it's a big IF, the temperatures displayed on todays instrumentation "WOULD" have displayed the same temperatures as those recorded by Lycoming technicians=C3, on the instrumentation used by Lycoming. =C3,=C2 Gary... I don't belief that is a big "IF"... The electrical characteristics of a type J thermocouple have been well known from long before WWII. The electrical instrumentation bit has not changed over the years as far as the basic thermocouple, especially when used in an engine test cell.=C2 I bet Lycoming had individual CHT meters directly connected to the probes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a type J thermocouple has always created the same amount of voltage due to physics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change.=C2 Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs...=C2 gil A =C2 ITS-90 Table for type J=C2 thermocouple =C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 9=C2 =C2 =C2 =C2 10 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 Thermoelectric Voltage in mV =C2 =C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 0.507 =C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 1.019 =C2 20=C2 1.019=C2 1.071 1.122=C2 1.174=C2 1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 1.537 =C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 2.059 =C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 2.585 =C2 =C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 3.116 =C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 3.650 =C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 4.187 =C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 4.726 =C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 5.269 =C2 =C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 5.814 =C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 6.360 =C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 6.909 =C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 7.459 =C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 8.010 =C2 =C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 8.562 =C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 9.115 =C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 9.669 =C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 =C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 =C2 =C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 =C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 =C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 =C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 =C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 =C2 =C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 =C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 =C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 =C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 =C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. 216 16.272 16.327 or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List p://forums.matronics.com ution">http://www.matronics.com/contribution ------------------------------------------------------------------------ A Good Credit Score is 700 or Above. ?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D6 68072%26hmpgID%3D62%26bcd%3DfebemailfooterNO62"> See yours in just 2 easy steps! href=" http://www.matronics.com/Navigator?TeamGrumman-List ">http://www.matronics.com/Navigator?TeamGrumman-List href=" http://forums.matronics.com">http://forums.matronics.com href=" http://www.matronics.com/contribution ">http://www.matronics.com/c ________________________________ Message 11 ____________________________________ Time: 07:33:17 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Gil, You didn't read the post very well. I removed all but the one sentence from the post that you missed. Want to change your belief? Ned ----- Original Message ----- From: Gil Alexander Sent: Sunday, March 29, 2009 9:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A "I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter." ________________________________ Message 12 ____________________________________ Time: 07:35:23 PM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: RE: EI vs JPI Maybe you guys need to ask Steve Peach about the two different styles of EI probes, bayonet and standard P-100, that he tested and found very little d ifference between the two. The large differences in temperature mentioned are between JPI with the bayonet and EI with the fixed probe. And all the accusations, or implications at least, are that the fixed EI probe does not measure the true temperature. There is a real possibility that it could b e due to something completely different. Cliff ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 7:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification=3F I vote for probes that touch the cylinder. gil A At 07:05 PM 3/29/2009, you wrote: I started this thread because of similar thread that was started on the GG. I understood one poster to say that he too had experienced higher read ings with JPI type probes that actually touch the thermowell. He had both i n his Cheetah and found that the probes that touch the head actually give a higher reading. So in answer to Gil's post it appears that others have noted the diffen ece in temp readings besides Gary. Someone at Lycoming needs to answer this question, at least the questio n of the type of probe they used. Right now we are just speculating on what type of probe they used. Ned Here is the post I refer to: ----- Original Message ----- From: John Horton To: 'Dave Kalwick' ; 'GG' Sent: Tuesday, March 24, 2009 9:19 PM Subject: RE: Tiger outlet ramps - More Info Req. Dave, I would direct you to look at http://www.bondline.org/wiki/Lower=5FCowling=5FSplit for info about reworking the exit ramps. That link will only provide i nfo about the metal exit ramps but that's half the options. When you mention that your temps are =22warm=22 be sure to review the GG ar chives about JPI instrumentation vs EI instrumentation. There are differences in probe design that make JPI read higher that EI in what should be the same cyl inder. So if you have JP CHT and think your running =22warm=22 you might be just f ine if you had EI CHT. Theres a good bit of reading in the archives on that t opic. My consensus after reviewing (and I might still have it wrong) is that JP CHT reads hotter than EI due to the fact that the JP CHT probe actually is spring loaded to touch the cyl head. The EI CHT probe screws into a space in the cyl head. I have had both in my plane (Cheetah) and can verify that fact. The probe s are different and the JP touches the head and reads hotter. So if you have JP CHT gauge and it reads 420 in climb your most likely fine. (Assuming the temp goes down when you level out) The same plane may wel l read 385 with a EI CHT and it is fine also. Be sure to know your temp source (EI or JP) and read the archives to get a feel for the differences before you go and rework your exit ramps. They might be fine. I recently reworked my exit ramps on my Cheetah due to a =22warmer=22 than I'd like #4 cyl, cracks in my metal exit ramps and a newly minted A&P ticket tha t allowed me to do it. I have only flown it once and the results looked promising .. Tommorrow I hope to gather more flight data. I currently have a JP CHT/ EGT and in climb prior to the ramp work could occasionally hit 450 (my and Lyco mings redline). I could easily get into the 430's in climb and have to nose over and or throttle back to arrest the CHT rise. When I had the EI CHT gauge I never saw anything above 390. After reworking the ramps I do expect to go faster, climb higher and do it all with 1/3 flaps deployed for less gallons per hour. I just had to throw that in in case there aren't enough emotionally loaded topics to write about. John Horton HC Cheetah Sensenich Prop ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 8:41 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Gary, How many STCs have you installed with poor/bad/wrong instructions=3F A nd the CHT/EGT monitor STCs are quite =22generic=22 not really airframe specifi c. My latest one was my Plane Power voltage regulator. Works fine, but needed spacers to clear the =22bumps=22 on the fire wall - hardly a drop-in exa ct replacement for the non flat bottom mechanical regulator - and no mentio n in the STC instructions. Your plane seems to be the only test case reporting the problem. I'm happy with the Insight GEM in mine with it's probes that touch the thermow ell bottom like I believe the Lycoming test bayonet probes did during their certification. As an electronics engineer, I know I would not design sensitive milli volts equipment using grounded sensors.... but that's just me.... and my st uff is (or has been) working in military aircraft and space vehicles....:^) gil A PS ...I like the GEM unit, but I have the =22bars only=22 version - I wou ld prefer the version with numbers - a probable future upgrade. PPS Sorry about the formatting of the mV chart in my previous e-mail Here is an alternate link to another table of National Institute of S tandards and Technology output voltages from a Type J thermocouple - http://www.omega.com/temperature/Z/pdf/z203.pdf This shows how small the DC voltages are that we are measuring. At 05:40 PM 3/29/2009, you wrote: There is something else going on here in your plane - and since w e are dealing with fractions of milliVolts, I would personally vote for gro unding issues.=C2 MY PLANE=3F =C2 Ok, maybe your right. =C2 The grounds in installed accord ing to the STC were done wrong. =C2 Maybe the probes grounding against brand new cylinders had corrosion built up in them. =C2 Maybe planes experiencing CHT readings higher on a JPI than on an E I also followed the installation instructions. How about you doing your own testing and report your own results=3F -----Original Message----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sun, 29 Mar 2009 12:03 pm Subject: Re: TeamGrumman-List: RE: EI vs JPI This is only true if, and it's a big IF, the temperatures display ed on todays instrumentation =22WOULD=22 have displayed the same temperatures a s those recorded by Lycoming technicians=C3, on the instrumentation used by L ycoming. =C3,=C2 Gary... I don't belief that is a big =22IF=22... The electrical characteristics of a type J thermocouple have been w ell known from long before WWII. The electrical instrumentation bit has not changed over the years a s far as the basic thermocouple, especially when used in an engine test cel l.=C2 I bet Lycoming had individual CHT meters directly connected to the pro bes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a t ype J thermocouple has always created the same amount of voltage due to phy sics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for groun ding issues.=C2 You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change.=C2 Try a direct wire from GND on your EI ga uge to the engine. This is from Sandia labs...=C2 gil A =C2 ITS-90 Table for type J=C2 thermocouple =C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 9=C2 =C2 =C2 =C2 10 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 Thermoelectric Voltage in mV =C2 =C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 0.507 =C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 1.019 =C2 20=C2 1.019=C2 1.071 1.122=C2 1.174=C2 1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 1.537 =C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 2.059 =C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 2.585 =C2 =C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 3.116 =C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 3.650 =C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 4.187 =C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 4.726 =C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 5.269 =C2 =C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 5.814 =C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 6.360 =C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 6.909 =C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 7.459 =C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 8.010 =C2 =C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 8.562 =C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 9.115 =C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 9.669 =C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 =C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 =C2 =C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 =C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 =C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 =C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 =C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 =C2 =C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 =C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 =C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 =C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 =C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. 216 16.272 16.327 or=3FTeamGrumman-List=22>http://www.matronics.com/Navigator=3FTeamGrumman-List p://forums.matronics.com ution=22>http://www.matronics.com/contribution ------------------------------------------------------------------------ A Good Credit Score is 700 or Above. =3Fredir=http:%2F%2Fwww.freecred itreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D668072%26hmpgID%3D62%26bcd%3Dfebema ilfooterNO62=22> See yours in just 2 easy steps! 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The Professional version does not have this message ________________________________ Message 13 ____________________________________ Time: 07:46:26 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Yeah I just Read Steve's post again. Steve didn't use JPI and JPI probers. He used solely EI equipment His post last year is here: http://grumman.net/archive/2008/msg00193.html I think that the idea that it is the EI fixed probe that is in error is a new idea recently introduced into this year and a half long thread. Last year and in Gary's article in the STAR the conclusion was that the JPI probe did not represent what Lycoming measured. At this point it is just speculation as to what type probe was used by Lycoming or perhaps even if they used a probe. Like Sgt Friday says lets just say with the facts... just the facts ----- Original Message ----- From: flyv35b To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:35 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Maybe you guys need to ask Steve Peach about the two different styles of EI probes, bayonet and standard P-100, that he tested and found very little difference between the two. The large differences in temperature mentioned are between JPI with the bayonet and EI with the fixed probe. And all the accusations, or implications at least, are that the fixed EI probe does not measure the true temperature. There is a real possibility that it could be due to something completely different. Cliff ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 7:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A At 07:05 PM 3/29/2009, you wrote: I started this thread because of similar thread that was started on the GG. I understood one poster to say that he too had experienced higher readings with JPI type probes that actually touch the thermowell. He had both in his Cheetah and found that the probes that touch the head actually give a higher reading. So in answer to Gil's post it appears that others have noted the diffenece in temp readings besides Gary. Someone at Lycoming needs to answer this question, at least the question of the type of probe they used. Right now we are just speculating on what type of probe they used. Ned Here is the post I refer to: ----- Original Message ----- From: John Horton To: 'Dave Kalwick' ; 'GG' Sent: Tuesday, March 24, 2009 9:19 PM Subject: RE: Tiger outlet ramps - More Info Req. Dave, I would direct you to look at http://www.bondline.org/wiki/Lower_Cowling_Split for info about reworking the exit ramps. That link will only provide info about the metal exit ramps but that's half the options. When you mention that your temps are "warm" be sure to review the GG archives about JPI instrumentation vs EI instrumentation. There are differences in probe design that make JPI read higher that EI in what should be the same cylinder. So if you have JP CHT and think your running "warm" you might be just fine if you had EI CHT. Theres a good bit of reading in the archives on that topic. My consensus after reviewing (and I might still have it wrong) is that JP CHT reads hotter than EI due to the fact that the JP CHT probe actually is spring loaded to touch the cyl head. The EI CHT probe screws into a space in the cyl head. I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter. So if you have JP CHT gauge and it reads 420 in climb your most likely fine. (Assuming the temp goes down when you level out) The same plane may well read 385 with a EI CHT and it is fine also. Be sure to know your temp source (EI or JP) and read the archives to get a feel for the differences before you go and rework your exit ramps. They might be fine. I recently reworked my exit ramps on my Cheetah due to a "warmer" than I'd like #4 cyl, cracks in my metal exit ramps and a newly minted A&P ticket that allowed me to do it. I have only flown it once and the results looked promising. Tommorrow I hope to gather more flight data. I currently have a JP CHT/EGT and in climb prior to the ramp work could occasionally hit 450 (my and Lycomings redline). I could easily get into the 430's in climb and have to nose over and or throttle back to arrest the CHT rise. When I had the EI CHT gauge I never saw anything above 390. After reworking the ramps I do expect to go faster, climb higher and do it all with 1/3 flaps deployed for less gallons per hour. I just had to throw that in in case there aren't enough emotionally loaded topics to write about. John Horton HC Cheetah Sensenich Prop ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 8:41 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Gary, How many STCs have you installed with poor/bad/wrong instructions? And the CHT/EGT monitor STCs are quite "generic" not really airframe specific. My latest one was my Plane Power voltage regulator. Works fine, but needed spacers to clear the "bumps" on the fire wall - hardly a drop-in exact replacement for the non flat bottom mechanical regulator - and no mention in the STC instructions. Your plane seems to be the only test case reporting the problem. I'm happy with the Insight GEM in mine with it's probes that touch the thermowell bottom like I believe the Lycoming test bayonet probes did during their certification. As an electronics engineer, I know I would not design sensitive millivolts equipment using grounded sensors.... but that's just me.... and my stuff is (or has been) working in military aircraft and space vehicles....:^) gil A PS ...I like the GEM unit, but I have the "bars only" version - I would prefer the version with numbers - a probable future upgrade. PPS Sorry about the formatting of the mV chart in my previous e-mail Here is an alternate link to another table of National Institute of Standards and Technology output voltages from a Type J thermocouple - http://www.omega.com/temperature/Z/pdf/z203.pdf This shows how small the DC voltages are that we are measuring. At 05:40 PM 3/29/2009, you wrote: There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 MY PLANE? =C2 Ok, maybe your right. =C2 The grounds in installed according to the STC were done wrong. =C2 Maybe the probes grounding against brand new cylinders had corrosion built up in them. =C2 Maybe planes experiencing CHT readings higher on a JPI than on an EI also followed the installation instructions. How about you doing your own testing and report your own results? -----Original Message----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sun, 29 Mar 2009 12:03 pm Subject: Re: TeamGrumman-List: RE: EI vs JPI This is only true if, and it's a big IF, the temperatures displayed on todays instrumentation "WOULD" have displayed the same temperatures as those recorded by Lycoming technicians=C3, on the instrumentation used by Lycoming. =C3,=C2 Gary... I don't belief that is a big "IF"... The electrical characteristics of a type J thermocouple have been well known from long before WWII. The electrical instrumentation bit has not changed over the years as far as the basic thermocouple, especially when used in an engine test cell.=C2 I bet Lycoming had individual CHT meters directly connected to the probes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a type J thermocouple has always created the same amount of voltage due to physics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change.=C2 Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs...=C2 gil A =C2 ITS-90 Table for type J=C2 thermocouple =C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 9=C2 =C2 =C2 =C2 10 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 Thermoelectric Voltage in mV =C2 =C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 0.507 =C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 1.019 =C2 20=C2 1.019=C2 1.071 1.122=C2 1.174=C2 1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 1.537 =C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 2.059 =C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 2.585 =C2 =C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 3.116 =C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 3.650 =C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 4.187 =C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 4.726 =C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 5.269 =C2 =C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 5.814 =C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 6.360 =C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 6.909 =C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 7.459 =C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 8.010 =C2 =C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 8.562 =C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 9.115 =C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 9.669 =C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 =C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 =C2 =C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 =C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 =C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 =C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 =C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 =C2 =C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 =C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 =C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 =C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 =C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. 216 16.272 16.327 or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List p://forums.matronics.com ution">http://www.matronics.com/contribution ---------------------------------------------------------------------- A Good Credit Score is 700 or Above. ?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D6 68072%26hmpgID%3D62%26bcd%3DfebemailfooterNO62"> See yours in just 2 easy steps! href=" http://www.matronics.com/Navigator?TeamGrumman-List ">http://www.matronics.com/Navigator?TeamGrumman-List href=" http://forums.matronics.com">http://forums.matronics.com href=" http://www.matronics.com/contribution ">http://www.matronics.com/c ------------------------------------------------------------------------- --- 3/28/2009 7:16 AM ------------------------------------------------------------------------- ----- We are a community of 6 million users fighting spam. ________________________________ Message 14 ____________________________________ Time: 07:46:34 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Steve's conclusion "the EI longer P-101 probe does indeed read hotter than the short P-100 probe by about 3.5 degrees F" ----- Original Message ----- From: flyv35b To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:35 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Maybe you guys need to ask Steve Peach about the two different styles of EI probes, bayonet and standard P-100, that he tested and found very little difference between the two. The large differences in temperature mentioned are between JPI with the bayonet and EI with the fixed probe. And all the accusations, or implications at least, are that the fixed EI probe does not measure the true temperature. There is a real possibility that it could be due to something completely different. Cliff ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 7:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A At 07:05 PM 3/29/2009, you wrote: I started this thread because of similar thread that was started on the GG. I understood one poster to say that he too had experienced higher readings with JPI type probes that actually touch the thermowell. He had both in his Cheetah and found that the probes that touch the head actually give a higher reading. So in answer to Gil's post it appears that others have noted the diffenece in temp readings besides Gary. Someone at Lycoming needs to answer this question, at least the question of the type of probe they used. Right now we are just speculating on what type of probe they used. Ned Here is the post I refer to: ----- Original Message ----- From: John Horton To: 'Dave Kalwick' ; 'GG' Sent: Tuesday, March 24, 2009 9:19 PM Subject: RE: Tiger outlet ramps - More Info Req. Dave, I would direct you to look at http://www.bondline.org/wiki/Lower_Cowling_Split for info about reworking the exit ramps. That link will only provide info about the metal exit ramps but that's half the options. When you mention that your temps are "warm" be sure to review the GG archives about JPI instrumentation vs EI instrumentation. There are differences in probe design that make JPI read higher that EI in what should be the same cylinder. So if you have JP CHT and think your running "warm" you might be just fine if you had EI CHT. Theres a good bit of reading in the archives on that topic. My consensus after reviewing (and I might still have it wrong) is that JP CHT reads hotter than EI due to the fact that the JP CHT probe actually is spring loaded to touch the cyl head. The EI CHT probe screws into a space in the cyl head. I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter. So if you have JP CHT gauge and it reads 420 in climb your most likely fine. (Assuming the temp goes down when you level out) The same plane may well read 385 with a EI CHT and it is fine also. Be sure to know your temp source (EI or JP) and read the archives to get a feel for the differences before you go and rework your exit ramps. They might be fine. I recently reworked my exit ramps on my Cheetah due to a "warmer" than I'd like #4 cyl, cracks in my metal exit ramps and a newly minted A&P ticket that allowed me to do it. I have only flown it once and the results looked promising. Tommorrow I hope to gather more flight data. I currently have a JP CHT/EGT and in climb prior to the ramp work could occasionally hit 450 (my and Lycomings redline). I could easily get into the 430's in climb and have to nose over and or throttle back to arrest the CHT rise. When I had the EI CHT gauge I never saw anything above 390. After reworking the ramps I do expect to go faster, climb higher and do it all with 1/3 flaps deployed for less gallons per hour. I just had to throw that in in case there aren't enough emotionally loaded topics to write about. John Horton HC Cheetah Sensenich Prop ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 8:41 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Gary, How many STCs have you installed with poor/bad/wrong instructions? And the CHT/EGT monitor STCs are quite "generic" not really airframe specific. My latest one was my Plane Power voltage regulator. Works fine, but needed spacers to clear the "bumps" on the fire wall - hardly a drop-in exact replacement for the non flat bottom mechanical regulator - and no mention in the STC instructions. Your plane seems to be the only test case reporting the problem. I'm happy with the Insight GEM in mine with it's probes that touch the thermowell bottom like I believe the Lycoming test bayonet probes did during their certification. As an electronics engineer, I know I would not design sensitive millivolts equipment using grounded sensors.... but that's just me.... and my stuff is (or has been) working in military aircraft and space vehicles....:^) gil A PS ...I like the GEM unit, but I have the "bars only" version - I would prefer the version with numbers - a probable future upgrade. PPS Sorry about the formatting of the mV chart in my previous e-mail Here is an alternate link to another table of National Institute of Standards and Technology output voltages from a Type J thermocouple - http://www.omega.com/temperature/Z/pdf/z203.pdf This shows how small the DC voltages are that we are measuring. At 05:40 PM 3/29/2009, you wrote: There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 MY PLANE? =C2 Ok, maybe your right. =C2 The grounds in installed according to the STC were done wrong. =C2 Maybe the probes grounding against brand new cylinders had corrosion built up in them. =C2 Maybe planes experiencing CHT readings higher on a JPI than on an EI also followed the installation instructions. How about you doing your own testing and report your own results? -----Original Message----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sun, 29 Mar 2009 12:03 pm Subject: Re: TeamGrumman-List: RE: EI vs JPI This is only true if, and it's a big IF, the temperatures displayed on todays instrumentation "WOULD" have displayed the same temperatures as those recorded by Lycoming technicians=C3, on the instrumentation used by Lycoming. =C3,=C2 Gary... I don't belief that is a big "IF"... The electrical characteristics of a type J thermocouple have been well known from long before WWII. The electrical instrumentation bit has not changed over the years as far as the basic thermocouple, especially when used in an engine test cell.=C2 I bet Lycoming had individual CHT meters directly connected to the probes, none of this fancy digital switching, scanning stuff....:^) Today the probes and the interconnect may be different, but the a type J thermocouple has always created the same amount of voltage due to physics. There is something else going on here in your plane - and since we are dealing with fractions of milliVolts, I would personally vote for grounding issues.=C2 You can see from the table below that 10 degrees Centigrade is about a 1/2 milliVolt change.=C2 Try a direct wire from GND on your EI gauge to the engine. This is from Sandia labs...=C2 gil A =C2 ITS-90 Table for type J=C2 thermocouple =C2 =C2=B0C=C2 =C2 =C2 =C2 =C2 0=C2 =C2 =C2 =C2 =C2 1=C2 =C2 =C2 =C2 =C2 2=C2 =C2 =C2 =C2 =C2 3=C2 =C2 =C2 =C2 =C2 4=C2 =C2 =C2 =C2 =C2 5=C2 =C2 =C2 =C2 =C2 6=C2 =C2 =C2 =C2 =C2 7=C2 =C2 =C2 =C2 =C2 8=C2 =C2 =C2 =C2 =C2 9=C2 =C2 =C2 =C2 10 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 =C2 Thermoelectric Voltage in mV =C2 =C2 =C2 0=C2 0.000=C2 0.050=C2 0.101=C2 0.151=C2 0.202=C2 0.253=C2 0.303=C2 0.354=C2 0.405=C2 0.456=C2 0.507 =C2 10=C2 0.507=C2 0.558=C2 0.609=C2 0.660=C2 0.711=C2 0.762=C2 0.814=C2 0.865=C2 0.916=C2 0.968=C2 1.019 =C2 20=C2 1.019=C2 1.071 1.122=C2 1.174=C2 1.226=C2 1.277=C2 1.329=C2 1.381=C2 1.433=C2 1.485=C2 1.537 =C2 30=C2 1.537=C2 1.589=C2 1.641=C2 1.693=C2 1.745=C2 1.797=C2 1.849=C2 1.902=C2 1.954=C2 2.006=C2 2.059 =C2 40=C2 2.059=C2 2.111=C2 2.164=C2 2.216=C2 2.269=C2 2.322=C2 2.374=C2 2.427=C2 2.480=C2 2.532=C2 2.585 =C2 =C2 50=C2 2.585=C2 2.638=C2 2.691=C2 2.744=C2 2.797=C2 2.850=C2 2.903=C2 2.956=C2 3.009=C2 3.062=C2 3.116 =C2 60=C2 3.116=C2 3.169=C2 3.222=C2 3.275=C2 3.329=C2 3.382=C2 3.436=C2 3.489=C2 3.543=C2 3.596=C2 3.650 =C2 70=C2 3.650=C2 3.703=C2 3.757=C2 3.810=C2 3.864=C2 3.918=C2 3.971=C2 4.025=C2 4.079=C2 4.133=C2 4.187 =C2 80=C2 4.187=C2 4.240=C2 4.294=C2 4.348=C2 4.402=C2 4.456=C2 4.510=C2 4.564=C2 4.618=C2 4.672=C2 4.726 =C2 90=C2 4.726=C2 4.781=C2 4.835=C2 4.889=C2 4.943=C2 4.997=C2 5.052=C2 5.106=C2 5.160=C2 5.215=C2 5.269 =C2 =C2 100=C2 5.269=C2 5.323=C2 5.378=C2 5.432=C2 5.487=C2 5.541=C2 5.595=C2 5.650=C2 5.705=C2 5.759=C2 5.814 =C2 110=C2 5.814=C2 5.868=C2 5.923=C2 5.977=C2 6.032=C2 6.087=C2 6.141=C2 6.196=C2 6.251=C2 6.306=C2 6.360 =C2 120=C2 6.360=C2 6.415=C2 6.470=C2 6.525=C2 6.579=C2 6.634=C2 6.689=C2 6.744=C2 6.799=C2 6.854=C2 6.909 =C2 130=C2 6.909=C2 6.964=C2 7.019=C2 7.074=C2 7.129=C2 7.184=C2 7.239=C2 7.294=C2 7.349=C2 7.404=C2 7.459 =C2 140=C2 7.4590 7.514=C2 7.569=C2 7.624=C2 7.679=C2 7.734=C2 7.789=C2 7.844=C2 7.900=C2 7.955=C2 8.010 =C2 =C2 150=C2 8.010=C2 8.065=C2 8.120=C2 8.175=C2 8.231=C2 8.286=C2 8.341=C2 8.396=C2 8.452=C2 8.507=C2 8.562 =C2 160=C2 8.562=C2 8.618=C2 8.673=C2 8.728=C2 8.783=C2 8.839=C2 8.894=C2 8.949=C2 9.005=C2 9.060=C2 9.115 =C2 170=C2 9.115=C2 9.171=C2 9.226=C2 9.282=C2 9.337=C2 9.392=C2 9.448=C2 9.503=C2 9.559=C2 9.614=C2 9.669 =C2 180=C2 9.669=C2 9.725=C2 9.780=C2 9.836=C2 9.891=C2 9.947 10.002 10.057 10.113 10.168 10.224 =C2 190 10.224 10.279 10.335 10.390 10.446 10.501 10.557 10.612 10.668 10.723 10.779 =C2 =C2 200 10.779 10.834 10.890 10.945 11.001 11.056 11.112 11.167 11.223 11.278 11.334 =C2 210 11.334 11.389 11.445 11.501 11.556 11.612 11.667 11.723 11.778 11.834 11.889 =C2 220 11.889 11.945 12.000 12.056 12.111 12.167 12.222 12.278 12.334 12.389 12.445 =C2 230 12.445 12.500 12.556 12.611 12.667 12.722 12.778 12.833 12.889 12.944 13.000 =C2 240 13.000 13.056 13.111 13.167 13.222 13.278 13.333 13.389 13.444 13.500 13.555 =C2 =C2 250 13.555 13.611 13.666 13.722 13.777 13.833 13.888 13.944 13.999 14.055 14.110 =C2 260 14.110 14.166 14.221 14.277 14.332 14.388 14.443 14.499 14.554 14.609 14.665 =C2 270 14.665 14.720 14.776 14.831 14.887 14.942 14.998 15.053 15.109 15.164 15.219 =C2 280 15.219 15.275 15.330 15.386 15.441 15.496 15.552 15.607 15.663 15.718 15.773 =C2 290 15.773 15.829 15.884 15.940 15.995 16.050 16.106 16.161 16. 216 16.272 16.327 or?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List p://forums.matronics.com ution">http://www.matronics.com/contribution ---------------------------------------------------------------------- A Good Credit Score is 700 or Above. ?redir=http:%2F%2Fwww.freecreditreport.com%2Fpm%2Fdefault.aspx%3Fsc%3D6 68072%26hmpgID%3D62%26bcd%3DfebemailfooterNO62"> See yours in just 2 easy steps! href=" http://www.matronics.com/Navigator?TeamGrumman-List ">http://www.matronics.com/Navigator?TeamGrumman-List href=" http://forums.matronics.com">http://forums.matronics.com href=" http://www.matronics.com/contribution ">http://www.matronics.com/c ------------------------------------------------------------------------- --- 3/28/2009 7:16 AM ------------------------------------------------------------------------- ----- We are a community of 6 million users fighting spam. ________________________________ Message 15 ____________________________________ Time: 07:51:43 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI Not according to the govt. web site that has specification records back to the 60's That's why I put it above speculation.... gil A At 07:31 PM 3/29/2009, you wrote: >Perhaps there was a milspec probe like the one EI uses today in use >on Lycomings certification tests... > >Like Isaid earlier we are just speculating >----- Original Message ----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sunday, March 29, 2009 9:13 PM >Subject: Re: TeamGrumman-List: RE: EI vs JPI > >Ned... I believe the GG post you refer to still references Gary's >EI/JPI measurements....:^) > >He just says below that the EI non-bayonet probes read lower - which >does not seem to be in dispute....:^) > >And do you really think Lycoming used a non-MIL-Spec probe, >especially in the 60's, for certification? I vote for probes that >touch the cylinder. > >gil A > >At 07:05 PM 3/29/2009, you wrote: >>I started this thread because of similar thread that was started on >>the GG. I understood one poster to say that he too had experienced >>higher readings with JPI type probes that actually touch the >>thermowell. He had both in his Cheetah and found that the probes >>that touch the head actually give a higher reading. >> >>So in answer to Gil's post it appears that others have noted the >>diffenece in temp readings besides Gary. >> >>Someone at Lycoming needs to answer this question, at least the >>question of the type of probe they used. Right now we are just >>speculating on what type of probe they used. > ________________________________ Message 16 ____________________________________ Time: 07:58:45 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI Sorry... I mixed up the vendors... I think the "touch the metal probes" (like the Mil-Spec ones) probably read higher. However, in agreement with Cliff - there well could be other things in play here when milliVolts are being measured. Grounds and differences in grounds, even along the wire to the instrument, could affect readings. That is why I suggest playing around with extra ground wires to see if the differences between the instruments change. The instrument ground to the engine case would seem to be the first obvious wire to try. gil A At 07:35 PM 3/29/2009, you wrote: >Gil, > >You didn't read the post very well. I removed all but the one >sentence from the post that you missed. Want to change your belief? >Ned > >----- Original Message ----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sunday, March 29, 2009 9:13 PM >Subject: Re: TeamGrumman-List: RE: EI vs JPI >Ned... I believe the GG post you refer to still references Gary's >EI/JPI measurements....:^) > >He just says below that the EI non-bayonet probes read lower - which >does not seem to be in dispute....:^) > >And do you really think Lycoming used a non-MIL-Spec probe, >especially in the 60's, for certification? I vote for probes that >touch the cylinder. > >gil A > > >"I have had both in my plane (Cheetah) and can verify that fact. The >probes are >different and the JP touches the head and reads hotter." > ________________________________ Message 17 ____________________________________ Time: 08:02:05 PM PST US From: linn Subject: Re: TeamGrumman-List: RE: EI vs JPI Are we really getting anal over 3.5 degrees??? Less than 1% error? Linn 923te wrote: > Steve's conclusion "the EI longer P-101 probe does indeed read hotter > than the short P-100 probe by about 3.5 degrees F" > > ----- Original Message ----- > ________________________________ Message 18 ____________________________________ Time: 08:04:05 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI I'm curious about the wire runs from the thermocouple to the instrument head. I know that some types like the old Alcor wires could not be cut. EI and JPI CAN be cut. I'm curious about that and about the effect for different length and routing under cylinders were the heat is higher. I think the theory behind teh system is to have one hot source (at the cylinder head) and one cold source ( at the gauge). I'd like to know more about the effects of multiple hot and cold sources along the wire ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:56 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Sorry... I mixed up the vendors... I think the "touch the metal probes" (like the Mil-Spec ones) probably read higher. However, in agreement with Cliff - there well could be other things in play here when milliVolts are being measured. Grounds and differences in grounds, even along the wire to the instrument, could affect readings. That is why I suggest playing around with extra ground wires to see if the differences between the instruments change. The instrument ground to the engine case would seem to be the first obvious wire to try. gil A At 07:35 PM 3/29/2009, you wrote: Gil, You didn't read the post very well. I removed all but the one sentence from the post that you missed. Want to change your belief? Ned ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A "I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter." ________________________________ Message 19 ____________________________________ Time: 08:04:30 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI No Linn, the difference in question is more like 70 deg F ----- Original Message ----- From: linn To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 11:04 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Are we really getting anal over 3.5 degrees??? Less than 1% error? Linn 923te wrote: Steve's conclusion "the EI longer P-101 probe does indeed read hotter than the short P-100 probe by about 3.5 degrees F" ----- Original Message ----- ________________________________ Message 20 ____________________________________ Time: 08:13:46 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... try this for a starter... gil A http://www.aeroelectric.com/articles/excerpt.pdf At 08:06 PM 3/29/2009, you wrote: >I'm curious about the wire runs from the thermocouple to the >instrument head. I know that some types like the old Alcor wires >could not be cut. EI and JPI CAN be cut. I'm curious about that and >about the effect for different length and routing under cylinders >were the heat is higher. I think the theory behind teh system is to >have one hot source (at the cylinder head) and one cold source ( at >the gauge). I'd like to know more about the effects of multiple hot >and cold sources along the wire >----- Original Message ----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sunday, March 29, 2009 9:56 PM >Subject: Re: TeamGrumman-List: RE: EI vs JPI > >Sorry... I mixed up the vendors... > >I think the "touch the metal probes" (like the Mil-Spec ones) >probably read higher. > >However, in agreement with Cliff - there well could be other things >in play here when milliVolts are being measured. > >Grounds and differences in grounds, even along the wire to the >instrument, could affect readings. > >That is why I suggest playing around with extra ground wires to see >if the differences between the instruments change. The instrument >ground to the engine case would seem to be the first obvious wire to try. > >gil A > >At 07:35 PM 3/29/2009, you wrote: >>Gil, >> >>You didn't read the post very well. I removed all but the one >>sentence from the post that you missed. Want to change your belief? >>Ned >> >>----- Original Message ----- >>From: Gil Alexander >>To: teamgrumman-list@matronics.com >>Sent: Sunday, March 29, 2009 9:13 PM >>Subject: Re: TeamGrumman-List: RE: EI vs JPI >>Ned... I believe the GG post you refer to still references Gary's >>EI/JPI measurements....:^) >> >>He just says below that the EI non-bayonet probes read lower - >>which does not seem to be in dispute....:^) >> >>And do you really think Lycoming used a non-MIL-Spec probe, >>especially in the 60's, for certification? I vote for probes that >>touch the cylinder. >> >>gil A >> >> >>"I have had both in my plane (Cheetah) and can verify that fact. >>The probes are >>different and the JP touches the head and reads hotter." > > >href="http://www.matronics.com/Navigator?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List > >href="http://forums.matronics.com">http://forums.matronics.com > >href="http://www.matronics.com/contribution">http://www.matronics.com/c > ________________________________ Message 21 ____________________________________ Time: 08:20:34 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI I'm a big fan of Bob Knuckolls. We even had him speak at our Pulsar builders convention. I've read this before but I'll read it again. A brief scan seems to indicate no address of my questions tho... I have these questions because I know how Gary has routed his wires. Very nice hidden installation but it always mae me wonder if the under cylinder heat may have an affect ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 10:12 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... try this for a starter... gil A http://www.aeroelectric.com/articles/excerpt.pdf At 08:06 PM 3/29/2009, you wrote: I'm curious about the wire runs from the thermocouple to the instrument head. I know that some types like the old Alcor wires could not be cut. EI and JPI CAN be cut. I'm curious about that and about the effect for different length and routing under cylinders were the heat is higher. I think the theory behind teh system is to have one hot source (at the cylinder head) and one cold source ( at the gauge). I'd like to know more about the effects of multiple hot and cold sources along the wire ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:56 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Sorry... I mixed up the vendors... I think the "touch the metal probes" (like the Mil-Spec ones) probably read higher. However, in agreement with Cliff - there well could be other things in play here when milliVolts are being measured. Grounds and differences in grounds, even along the wire to the instrument, could affect readings. That is why I suggest playing around with extra ground wires to see if the differences between the instruments change. The instrument ground to the engine case would seem to be the first obvious wire to try. gil A At 07:35 PM 3/29/2009, you wrote: Gil, You didn't read the post very well. I removed all but the one sentence from the post that you missed. Want to change your belief? Ned ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A "I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter." href=" http://www.matronics.com/Navigator?TeamGrumman-List ">http://www.matronics.com/Navigator?TeamGrumman-List href=" http://forums.matronics.com">http://forums.matronics.com href=" http://www.matronics.com/contribution ">http://www.matronics.com/c ________________________________ Message 22 ____________________________________ Time: 08:27:26 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI The GEM also allows for cutting of the wire leads. This is probably due to modern electronics using FET transistor input devices with very high input resistances. The older specifications made a big deal of the thermocouple resistance, which makes me think that the older Alcor instruments were affected by total resistance in the leads with a completely different input circuit. This bit is definite, but informed, speculation...:^) Some more far out speculation - the lead connections could have changed over the last period of a few years due to the removal of lead from solder by EU and Japanese regulations - the RoHS Directive. Manufacturers have changed the plating composition on connectors that may come into play at the probe to lead wire connections. In lots of commercial cases (and a few Mil-Spec cases, unfortunately) these changes have NOT been reflected in part number changes. gil A At 08:06 PM 3/29/2009, you wrote: >I'm curious about the wire runs from the thermocouple to the >instrument head. I know that some types like the old Alcor wires >could not be cut. EI and JPI CAN be cut. I'm curious about that and >about the effect for different length and routing under cylinders >were the heat is higher. I think the theory behind teh system is to >have one hot source (at the cylinder head) and one cold source ( at >the gauge). I'd like to know more about the effects of multiple hot >and cold sources along the wire >----- Original Message ----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sunday, March 29, 2009 9:56 PM >Subject: Re: TeamGrumman-List: RE: EI vs JPI > >Sorry... I mixed up the vendors... > >I think the "touch the metal probes" (like the Mil-Spec ones) >probably read higher. > >However, in agreement with Cliff - there well could be other things >in play here when milliVolts are being measured. > >Grounds and differences in grounds, even along the wire to the >instrument, could affect readings. > >That is why I suggest playing around with extra ground wires to see >if the differences between the instruments change. The instrument >ground to the engine case would seem to be the first obvious wire to try. > >gil A > >At 07:35 PM 3/29/2009, you wrote: >>Gil, >> >>You didn't read the post very well. I removed all but the one >>sentence from the post that you missed. Want to change your belief? >>Ned >> >>----- Original Message ----- >>From: Gil Alexander >>To: teamgrumman-list@matronics.com >>Sent: Sunday, March 29, 2009 9:13 PM >>Subject: Re: TeamGrumman-List: RE: EI vs JPI >>Ned... I believe the GG post you refer to still references Gary's >>EI/JPI measurements....:^) >> >>He just says below that the EI non-bayonet probes read lower - >>which does not seem to be in dispute....:^) >> >>And do you really think Lycoming used a non-MIL-Spec probe, >>especially in the 60's, for certification? I vote for probes that >>touch the cylinder. >> >>gil A >> >> >>"I have had both in my plane (Cheetah) and can verify that fact. >>The probes are >>different and the JP touches the head and reads hotter." > > >href="http://www.matronics.com/Navigator?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List > >href="http://forums.matronics.com">http://forums.matronics.com > >href="http://www.matronics.com/contribution">http://www.matronics.com/c > ________________________________ Message 23 ____________________________________ Time: 08:32:24 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI At 08:22 PM 3/29/2009, you wrote: >I'm a big fan of Bob Knuckolls. We even had him speak at our Pulsar >builders convention. I've read this before but I'll read it again. A >brief scan seems to indicate no address of my questions tho... > >I have these questions because I know how Gary has routed his wires. >Very nice hidden installation but it always mae me wonder if the >under cylinder heat may have an affect The critical portion would be not the leads themselves but the probe/lead connection, which is only a short distance from the probes, and in the hot area by your description above. gil A ________________________________ Message 24 ____________________________________ Time: 08:36:45 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Interesting Gil, we know that temperature affects resistance. Also, Length of wire is a concern. for example, if you cut the thermocouple wires and make them different lengths from the heat source to the cold source so that some stay hotter than others and resistance is not constant what effect would that have on the algorithm that puts the numbers on the the gauge? ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 10:26 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI The GEM also allows for cutting of the wire leads. This is probably due to modern electronics using FET transistor input devices with very high input resistances. The older specifications made a big deal of the thermocouple resistance, which makes me think that the older Alcor instruments were affected by total resistance in the leads with a completely different input circuit. This bit is definite, but informed, speculation...:^) Some more far out speculation - the lead connections could have changed over the last period of a few years due to the removal of lead from solder by EU and Japanese regulations - the RoHS Directive. Manufacturers have changed the plating composition on connectors that may come into play at the probe to lead wire connections. In lots of commercial cases (and a few Mil-Spec cases, unfortunately) these changes have NOT been reflected in part number changes. gil A At 08:06 PM 3/29/2009, you wrote: I'm curious about the wire runs from the thermocouple to the instrument head. I know that some types like the old Alcor wires could not be cut. EI and JPI CAN be cut. I'm curious about that and about the effect for different length and routing under cylinders were the heat is higher. I think the theory behind teh system is to have one hot source (at the cylinder head) and one cold source ( at the gauge). I'd like to know more about the effects of multiple hot and cold sources along the wire ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:56 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Sorry... I mixed up the vendors... I think the "touch the metal probes" (like the Mil-Spec ones) probably read higher. However, in agreement with Cliff - there well could be other things in play here when milliVolts are being measured. Grounds and differences in grounds, even along the wire to the instrument, could affect readings. That is why I suggest playing around with extra ground wires to see if the differences between the instruments change. The instrument ground to the engine case would seem to be the first obvious wire to try. gil A At 07:35 PM 3/29/2009, you wrote: Gil, You didn't read the post very well. I removed all but the one sentence from the post that you missed. Want to change your belief? Ned ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 9:13 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... I believe the GG post you refer to still references Gary's EI/JPI measurements....:^) He just says below that the EI non-bayonet probes read lower - which does not seem to be in dispute....:^) And do you really think Lycoming used a non-MIL-Spec probe, especially in the 60's, for certification? I vote for probes that touch the cylinder. gil A "I have had both in my plane (Cheetah) and can verify that fact. The probes are different and the JP touches the head and reads hotter." href=" http://www.matronics.com/Navigator?TeamGrumman-List ">http://www.matronics.com/Navigator?TeamGrumman-List href=" http://forums.matronics.com">http://forums.matronics.com href=" http://www.matronics.com/contribution ">http://www.matronics.com/c ________________________________ Message 25 ____________________________________ Time: 09:06:53 PM PST US From: Gil Alexander Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... more stuff. Excellent description - with pics - of grounded vs. ungrounded - interesting that grounded are faster respnse, but ungrounded are better in electrically noisy environments http://www.omega.com/custom/faq.html#9 Interesting comments on wire length and high impedance sensors here http://www.omega.com/prodinfo/ThermocoupleWire.html A good detailed reference - I need to absorb this one... http://www.omega.com/temperature/Z/pdf/z021-032.pdf more http://www.omega.com/techref/thermoref.html As you might guess, Omega is a premier US source of thermocouples....:^) A bit more basic one here... http://www.status.co.uk/data/handbook_sections_1_to_4.pdf Enough here to guarantee you will fall asleep quickly...:^) gil A >I'm a big fan of Bob Knuckolls. We even had him speak at our Pulsar >builders convention. I've read this before but I'll read it again. A >brief scan seems to indicate no address of my questions tho... > >I have these questions because I know how Gary has routed his wires. >Very nice hidden installation but it always mae me wonder if the >under cylinder heat may have an affect >----- Original Message ----- >From: Gil Alexander >To: teamgrumman-list@matronics.com >Sent: Sunday, March 29, 2009 10:12 PM >Subject: Re: TeamGrumman-List: RE: EI vs JPI > >Ned... try this for a starter... gil A > >http://www.aeroelectric.com/articles/excerpt.pdf > > >At 08:06 PM 3/29/2009, you wrote: >>I'm curious about the wire runs from the thermocouple to the >>instrument head. I know that some types like the old Alcor wires >>could not be cut. EI and JPI CAN be cut. I'm curious about that and >>about the effect for different length and routing under cylinders >>were the heat is higher. I think the theory behind teh system is to >>have one hot source (at the cylinder head) and one cold source ( at >>the gauge). I'd like to know more about the effects of multiple hot >>and cold sources along the wire >>----- Original Message ----- ________________________________ Message 26 ____________________________________ Time: 09:22:05 PM PST US From: "923te" <923te@att.net> Subject: Re: TeamGrumman-List: RE: EI vs JPI Thanks Gil. I was chasing rabbits whilst looking for some references. have most of the Omega books...guess I should dust them off...noooo it's just easier to use the net;) The rabbit...Interesting article on the history of temp / heat measurement http://www.springerlink.com/content/r1n5773kug453405/fulltext.pdf Actually got me to chase a rabbit to colditz Where there is a clay called the colditz clay that was used to make the secret formulae, at the time, porcelain. Back in the 1700's the king of Saxonia (east germany) evidently had teh European market on this typr of porclain... I keyed in on colditz because of its' significance during WWI and WWII as using their castle as a prisoner of war camp...the unescapable prison where during WWII the prisoners were constructing a GLIDER to launch from the top of the castle, thus the birdmen of colditz movie Isn't this forum great! no nanny to kick me off! ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 11:05 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... more stuff. Excellent description - with pics - of grounded vs. ungrounded - interesting that grounded are faster respnse, but ungrounded are better in electrically noisy environments http://www.omega.com/custom/faq.html#9 Interesting comments on wire length and high impedance sensors here http://www.omega.com/prodinfo/ThermocoupleWire.html A good detailed reference - I need to absorb this one... http://www.omega.com/temperature/Z/pdf/z021-032.pdf more http://www.omega.com/techref/thermoref.html As you might guess, Omega is a premier US source of thermocouples....:^) A bit more basic one here... http://www.status.co.uk/data/handbook_sections_1_to_4.pdf Enough here to guarantee you will fall asleep quickly...:^) gil A I'm a big fan of Bob Knuckolls. We even had him speak at our Pulsar builders convention. I've read this before but I'll read it again. A brief scan seems to indicate no address of my questions tho... I have these questions because I know how Gary has routed his wires. Very nice hidden installation but it always mae me wonder if the under cylinder heat may have an affect ----- Original Message ----- From: Gil Alexander To: teamgrumman-list@matronics.com Sent: Sunday, March 29, 2009 10:12 PM Subject: Re: TeamGrumman-List: RE: EI vs JPI Ned... try this for a starter... gil A http://www.aeroelectric.com/articles/excerpt.pdf At 08:06 PM 3/29/2009, you wrote: I'm curious about the wire runs from the thermocouple to the instrument head. I know that some types like the old Alcor wires could not be cut. EI and JPI CAN be cut. I'm curious about that and about the effect for different length and routing under cylinders were the heat is higher. I think the theory behind teh system is to have one hot source (at the cylinder head) and one cold source ( at the gauge). I'd like to know more about the effects of multiple hot and cold sources along the wire ----- Original Message ----- ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message teamgrumman-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/TeamGrumman-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/teamgrumman-list Browse Digests http://www.matronics.com/digest/teamgrumman-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.