---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Sun 09/28/08: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:39 AM - Re: CHT probe placement (Tex Mantell) 2. 06:06 AM - Re: CHT probe placement (Lynn Matteson) 3. 08:25 AM - Re: CHT probe placement (Tex Mantell) 4. 10:31 AM - Re: CHT probe placement (Jim Crowder) 5. 02:36 PM - Re: CHT probe placement (Lynn Matteson) 6. 03:23 PM - Re: CHT probe placement (Jim Crowder) 7. 09:36 PM - Re: CHT probe placement (Lynn Matteson) 8. 09:45 PM - Re: CHT probe placement (Craig Payne) 9. 11:22 PM - Re: CHT probe placement (Jim Crowder) 10. 11:41 PM - Re: CHT probe placement (Jim Crowder) ________________________________ Message 1 _____________________________________ Time: 04:39:32 AM PST US From: "Tex Mantell" Subject: Re: JabiruEngine-List: CHT probe placement Lynn, can you post a picture of where you placed the probe. Tex ----- Original Message ----- From: "Lynn Matteson" Sent: Saturday, September 27, 2008 8:03 PM Subject: JabiruEngine-List: CHT probe placement > > When I recently rebuilt my Jabiru 2200 engine, I decided it was time to > make the CHT probe move to a better location, and avoid the dreaded spark > plug gasket removal and replacement problem. I didn't like the idea of > putting the probe under a head bolt as some have done, fearing the idea > of putting 24 lbs of torque on a copper terminal, so I followed another > poster's idea and drilled and tapped a hole in the head between, and > slightly below, the spark plug locations. Now I find that the temperature > readings are quite a bit above the reported 10 degrees or so difference > (from the spark plug locations) that I have read about for the head bolt > locations. I have looked into this and have decided that the spark plug > probes (mine anyway) position the thermocouple wire attachment > point...the point where the actual reading is made, the "business end" if > you will, (and it is NOT the area that actually touches the > head)...one-half inch above the head surface, and well into the airflow > that goes past this area. This spark plug thermocouple is further > insulated by having it *above* the spark plug gasket, making it even > further from the cylinder head, albeit by a very small amount. I believe > this 1/2" of separation from the head is enough to place the "business > end" of the t'couple in the relatively cool air passing by. I used to see > CHT's of an average of about 275 F, while I now see my CHT's read about > 350-360 F, and up to about 385 F in climb, at 1500' MSL, @ 80 F > ambient. Straight and level flight after a 5 minute settling down period > after climbout will see the 350's I mentioned. My thermocouple attachment > point...the business end...is now closer to the head, and tucked between > the head and a fin instead of sticking up into the airflow, so I can > accept the higher readings, especially when the engine is running so > strong now and climbing better than I recall it doing before the engine > breakdown. I might add that each flight sees lower CHT's as the engine > breaks in. > Any comments? > > Lynn Matteson > Kitfox IV Speedster > Jabiru 2200, 562 hrs, and counting...all systems are go. > > > ________________________________ Message 2 _____________________________________ Time: 06:06:52 AM PST US From: Lynn Matteson Subject: Re: JabiruEngine-List: CHT probe placement Here ya go, Tex. I had to grind a bit off the fins just above the area, then level out the little hump, and it was clear sailing to drill it and tap it with an 8-32 tap. I just cut the old 12mm terminal off the t'couple lead, bared the leads a bit, shrink tubed them right up to the bare area and inserted them into a new #8 stud size, eye terminal. Where the leads contact each other is where the temp reading actually takes place, so be sure to shove the bare leads right up to the terminal before crimping. At least that's how this anal reporter did/does it. : ) Lynn Matteson Kitfox IV Speedster Jabiru 2200, 562 hrs, and counting...all systems are go. On Sep 28, 2008, at 7:38 AM, Tex Mantell wrote: > > > Lynn, can you post a picture of where you placed the probe. Tex > > ________________________________ Message 3 _____________________________________ Time: 08:25:24 AM PST US From: "Tex Mantell" Subject: Re: JabiruEngine-List: CHT probe placement Thanks , great pictures.. ----- Original Message ----- From: "Lynn Matteson" Sent: Sunday, September 28, 2008 9:04 AM Subject: Re: JabiruEngine-List: CHT probe placement > Here ya go, Tex. I had to grind a bit off the fins just above the > area, then level out the little hump, and it was clear sailing to > drill it and tap it with an 8-32 tap. I just cut the old 12mm > terminal off the t'couple lead, bared the leads a bit, shrink tubed > them right up to the bare area and inserted them into a new #8 stud > size, eye terminal. Where the leads contact each other is where the > temp reading actually takes place, so be sure to shove the bare leads > right up to the terminal before crimping. At least that's how this > anal reporter did/does it. : ) > > > Lynn Matteson > Kitfox IV Speedster > Jabiru 2200, 562 hrs, and counting...all systems are go. > > -------------------------------------------------------------------------------- > > -------------------------------------------------------------------------------- > > > On Sep 28, 2008, at 7:38 AM, Tex Mantell wrote: > >> >> >> Lynn, can you post a picture of where you placed the probe. Tex >> >> > ________________________________ Message 4 _____________________________________ Time: 10:31:38 AM PST US From: "Jim Crowder" Subject: RE: JabiruEngine-List: CHT probe placement Just what is a "#8 stud size, eye terminal." A picture of this would be a help to me. I have the 3300 and my engine has the small holes. I have not measured them precisely, but as I remember a 1/8" drill will fit inside. I also have the Grand Rapids EIS. I have been following your saga with great interest. Have you checked with GR to see if they might now offer a sensor that might fit or be more adaptable to the hole? As you have been experimenting with a small daylight readable screen HP tablet computer which I have interfaced to the GR EIS. I have programmed Excel spreadsheet to graphically display the output from the EIS. I will post pictures of all of this soon. I have also built my own cowling for my Kitfox 5 and then more recently greatly modified the lower cowl to increase the exit area and greatly modify the exit lip to hopefully increase the negative air pressure to further aid cooling. I did this without even checking the first version after all of the comments regarding cooling. I will also send pictures of this soon. My engine has yet to run, but in the next two months I hope to have all together. Jim Crowder > -----Original Message----- > From: owner-jabiruengine-list-server@matronics.com > [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of Lynn > Matteson > Sent: Sunday, September 28, 2008 7:05 AM > To: jabiruengine-list@matronics.com > Subject: Re: JabiruEngine-List: CHT probe placement > > > Here ya go, Tex. I had to grind a bit off the fins just above the > area, then level out the little hump, and it was clear sailing to > drill it and tap it with an 8-32 tap. I just cut the old 12mm > terminal off the t'couple lead, bared the leads a bit, shrink tubed > them right up to the bare area and inserted them into a new #8 stud > size, eye terminal. Where the leads contact each other is where the > temp reading actually takes place, so be sure to shove the bare leads > right up to the terminal before crimping. At least that's how this > anal reporter did/does it. : ) > > > Lynn Matteson > Kitfox IV Speedster > Jabiru 2200, 562 hrs, and counting...all systems are go. > > ________________________________ Message 5 _____________________________________ Time: 02:36:14 PM PST US From: Lynn Matteson Subject: Re: JabiruEngine-List: CHT probe placement If you go to the hardware store or auto parts store, and look for the electrical terminals, you will see that there are red, blue and yellow-colored terminals for wiring. The red ones are for wire sizes 22 to 18, the blue are for 16-14, I believe, and the yellows are for wire sizes 12 to 10 as I recall. The colors are the colors of the insulating sleeves that are fitted to the wire entry hole. That seems to be industry-wide color coding. The other sizing is the size of the eye, so a #8 stud size will fit over a #8 stud, or a #8 screw will go through the hole. When I said a "#8 stud size" that means a #8 screw will bolt the terminal to the head in this case. If you had a large wire, like a #10 wire, you would look for a #8 (in this case) for the hole size, but a #10 wire size. There are blade terminals, open eye terminals, and spade terminals, and possibly others, and this refers to the shape of the terminal where it makes a mechanical attachment to whatever you are fastening the wire to. In the case of your 1/8" hole in your head, that is close to the size needed to tap it to 8-32. The 8-32 tap calls for a #29 drill for the tap to work properly. A #29 drill measures .136", so you would want this size hole in your head to properly tap the hole with an 8-32 tap. If your hole is only 1/8" or .125", you will need to drill to . 136" or the tap will probably break from trying to force it to go into a hole that is too small. I have not checked with GR, preferring to just drill to the size needed for the 8-32 tap. Remember, I had no holes in my head, and needed to drill my own holes. I understand that some heads are already drilled, and it was Peter Disher's post regarding the already-drilled heads that led me to try this thermocouple placement on my heads. Your interfacing sounds like a great way to record data, Jim...wish I was more computer oriented, but a pencil and paper work for me, although I'm sure I miss a LOT of data. Lynn Matteson Kitfox IV Speedster Jabiru 2200, 562 hrs, and counting...all systems are go. On Sep 28, 2008, at 1:28 PM, Jim Crowder wrote: > > > Just what is a "#8 stud size, eye terminal." A picture of this > would be a > help to me. I have the 3300 and my engine has the small holes. I > have not > measured them precisely, but as I remember a 1/8" drill will fit > inside. I > also have the Grand Rapids EIS. I have been following your saga > with great > interest. Have you checked with GR to see if they might now offer > a sensor > that might fit or be more adaptable to the hole? > > As you have been experimenting with a small daylight readable > screen HP > tablet computer which I have interfaced to the GR EIS. I have > programmed > Excel spreadsheet to graphically display the output from the EIS. > I will > post pictures of all of this soon. I have also built my own > cowling for my > Kitfox 5 and then more recently greatly modified the lower cowl to > increase > the exit area and greatly modify the exit lip to hopefully increase > the > negative air pressure to further aid cooling. I did this without even > checking the first version after all of the comments regarding > cooling. I > will also send pictures of this soon. My engine has yet to run, > but in the > next two months I hope to have all together. > > Jim Crowder > >> -----Original Message----- >> From: owner-jabiruengine-list-server@matronics.com >> [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of >> Lynn >> Matteson >> Sent: Sunday, September 28, 2008 7:05 AM >> To: jabiruengine-list@matronics.com >> Subject: Re: JabiruEngine-List: CHT probe placement >> >> >> Here ya go, Tex. I had to grind a bit off the fins just above the >> area, then level out the little hump, and it was clear sailing to >> drill it and tap it with an 8-32 tap. I just cut the old 12mm >> terminal off the t'couple lead, bared the leads a bit, shrink tubed >> them right up to the bare area and inserted them into a new #8 stud >> size, eye terminal. Where the leads contact each other is where the >> temp reading actually takes place, so be sure to shove the bare leads >> right up to the terminal before crimping. At least that's how this >> anal reporter did/does it. : ) >> >> >> Lynn Matteson >> Kitfox IV Speedster >> Jabiru 2200, 562 hrs, and counting...all systems are go. >> >> >> > > ________________________________ Message 6 _____________________________________ Time: 03:23:17 PM PST US From: "Jim Crowder" Subject: RE: JabiruEngine-List: CHT probe placement Lynn, If others want, I will take this thread off line. I already understood most of what you have related. Just what you were referring to as the stud and the eye was not clear to me. I am also not clear on just what and how much remains outside of the hole. I was thinking you were somehow inserting the crimped portion containing the junction into the hole. I am now thinking you leave the crimped junction outside of the hole while threading the screw through the eye or ring of a terminal and into the hole. Will this not leave the actual sensor junction just above the head and then therefore depending on the heat transfer from the eye and terminal to the junction? Does this not leave the actual terminal end and the enclosed junction to remain in the air just above the head? This seems to be different than my son's bayonet sensor which as I remember inserts into a hole in his IO360 on his RV8 which is also about to fly. I have just spent most of the last two days bucking rivets with him as he finish closing his wings. We are about to take his plane out to my hangar for a coming first flight. I am concerned that if I make use of the holes as you are when making my first flights, I will not know if my CHT's readings are too high or low. Since you are further along in this, maybe you will have established the correct temperature thresholds. The computer interface has taken me a long time to get working and while it is nearly there and generally working on my bench, it is not yet complete. It is another whole discussion which I will share either when I am just a bit more finished, or as the group has interest. In my post to which you have replied, I meant to say "as you have been experimenting, I have been experimenting." You did seem to get my meaning, though. Jim Crowder Kitfox 5 3300 Jabiru Engine > -----Original Message----- > From: owner-jabiruengine-list-server@matronics.com > [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of Lynn > Matteson > Sent: Sunday, September 28, 2008 3:36 PM > To: jabiruengine-list@matronics.com > Subject: Re: JabiruEngine-List: CHT probe placement > > > > If you go to the hardware store or auto parts store, and look for the > electrical terminals, you will see that there are red, blue and > yellow-colored terminals for wiring. The red ones are for wire sizes > 22 to 18, the blue are for 16-14, I believe, and the yellows are for > wire sizes 12 to 10 as I recall. The colors are the colors of the > insulating sleeves that are fitted to the wire entry hole. That seems > to be industry-wide color coding. The other sizing is the size of the > eye, so a #8 stud size will fit over a #8 stud, or a #8 screw will go > through the hole. When I said a "#8 stud size" that means a #8 screw > will bolt the terminal to the head in this case. If you had a large > wire, like a #10 wire, you would look for a #8 (in this case) for the > hole size, but a #10 wire size. There are blade terminals, open eye > terminals, and spade terminals, and possibly others, and this refers > to the shape of the terminal where it makes a mechanical attachment > to whatever you are fastening the wire to. > > In the case of your 1/8" hole in your head, that is close to the size > needed to tap it to 8-32. The 8-32 tap calls for a #29 drill for the > tap to work properly. A #29 drill measures .136", so you would want > this size hole in your head to properly tap the hole with an 8-32 > tap. If your hole is only 1/8" or .125", you will need to drill to . > 136" or the tap will probably break from trying to force it to go > into a hole that is too small. I have not checked with GR, preferring > to just drill to the size needed for the 8-32 tap. Remember, I had no > holes in my head, and needed to drill my own holes. I understand that > some heads are already drilled, and it was Peter Disher's post > regarding the already-drilled heads that led me to try this > thermocouple placement on my heads. > > Your interfacing sounds like a great way to record data, Jim...wish I > was more computer oriented, but a pencil and paper work for me, > although I'm sure I miss a LOT of data. > > Lynn Matteson > Kitfox IV Speedster > Jabiru 2200, 562 hrs, and counting...all systems are go. > > > On Sep 28, 2008, at 1:28 PM, Jim Crowder wrote: > > > > > > > Just what is a "#8 stud size, eye terminal." A picture of this > > would be a > > help to me. I have the 3300 and my engine has the small holes. I > > have not > > measured them precisely, but as I remember a 1/8" drill will fit > > inside. I > > also have the Grand Rapids EIS. I have been following your saga > > with great > > interest. Have you checked with GR to see if they might now offer > > a sensor > > that might fit or be more adaptable to the hole? > > > > As you have been experimenting with a small daylight readable > > screen HP > > tablet computer which I have interfaced to the GR EIS. I have > > programmed > > Excel spreadsheet to graphically display the output from the EIS. > > I will > > post pictures of all of this soon. I have also built my own > > cowling for my > > Kitfox 5 and then more recently greatly modified the lower cowl to > > increase > > the exit area and greatly modify the exit lip to hopefully increase > > the > > negative air pressure to further aid cooling. I did this without even > > checking the first version after all of the comments regarding > > cooling. I > > will also send pictures of this soon. My engine has yet to run, > > but in the > > next two months I hope to have all together. > > > > Jim Crowder > > > >> -----Original Message----- > >> From: owner-jabiruengine-list-server@matronics.com > >> [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of > >> Lynn > >> Matteson > >> Sent: Sunday, September 28, 2008 7:05 AM > >> To: jabiruengine-list@matronics.com > >> Subject: Re: JabiruEngine-List: CHT probe placement > >> > >> > >> Here ya go, Tex. I had to grind a bit off the fins just above the > >> area, then level out the little hump, and it was clear sailing to > >> drill it and tap it with an 8-32 tap. I just cut the old 12mm > >> terminal off the t'couple lead, bared the leads a bit, shrink tubed > >> them right up to the bare area and inserted them into a new #8 stud > >> size, eye terminal. Where the leads contact each other is where the > >> temp reading actually takes place, so be sure to shove the bare leads > >> right up to the terminal before crimping. At least that's how this > >> anal reporter did/does it. : ) > >> > >> > >> Lynn Matteson > >> Kitfox IV Speedster > >> Jabiru 2200, 562 hrs, and counting...all systems are go. > >> > >> > >> > > > > > > > > > > > > ________________________________ Message 7 _____________________________________ Time: 09:36:27 PM PST US From: Lynn Matteson Subject: Re: JabiruEngine-List: CHT probe placement Yes, I use the hole that I drilled for the screw, and the crimped portion lays parallel to the head and very close to the surface..as close as a few thousandths from it....as close as the screw can clamp it to the surface. You could also do as you say, or suggest, cut off the eye and insert the crimped portion right into the hole if you could come up with a suitable way to retain it there. That may be how Peter Disher did his..see the archives from Aug 25, 2008 from this List...he has pictures there. I just forwarded this post to you. It *does* sound like he inserted the bare wires perhaps, right into the hole, then ran the screw into the hole. I suppose you could tap the hole, then maybe rout a small groove on one side of the hole in which to insert the bare wires of the t'couple. In any case, the closer to the head, or even right into it, the more accurate the reading. What we are dealing with here however is "uncharted waters", in that because no one else has done this, or reported their findings, we don't know just what the readings should be. That's where the pucker factor for my first flight came from. I was quick to get the plane off the ground, thinking that I'd better get it up there and get cooler air flowing over the engine. I was thinking that my seemingly elevated temps were the result of the newly honed cylinders and new piston rings causing high friction, but it was the more accurate readings of the t'couple probe placement that revealed the higher temps. So what IS the proper temp, now that we have the more accurate readings....beats me!! Maybe Jabiru knows. For me, I just tried to keep it below their posted max of 392 F, but it did go over that once, on the initial startup, running it on the ground. That's why I quickly got it into the air, and that act almost bit me in the butt. The tight engine wasn't climbing very well, so I kept it above tree level, climbing slightly and getting it turned around and landed. When I realized that the engine didn't feel any hotter than before, I started to realize that the feel of the engine was the same as before, but the readings were higher because the probe was no longer 1/2" away from the head, up into the airstream, being cooled and giving lower but inaccurate readings of the actual temp of the head. This is all fine and good if we all do it just the way Jabiru does it, with the spark plug probes. So I unpuckered, and began to accept that I would now be seeing 350-380 F as the norm....my norm, instead of the 275 of before. I guess this is where the "experimenting" part comes in. : ) I flew to an airport about 40 miles away today, and my head temps were running about 358 for the most part, and I've accepted that as my new norm. It comforts me to know that I haven't changed anything relating to airflow, so I'm accepting the higher readings as being "normal." I also wish that Jabiru would give us a socket for a bayonet sensor, or at least report what such a probe placement would reveal in the way of temps. Yes, I kind of read between the lines on your experimenting, and please do keep *us all* posted on your progress....I'm sure that this is the kind of thing that this List is meant to do...inform and share all aspects of Jabiru engine-related experimentation. At least that's the way I read it. Lynn Matteson Kitfox IV Speedster Jabiru 2200, 562 hrs, and counting...all systems are go, or nearly so... On Sep 28, 2008, at 6:22 PM, Jim Crowder wrote: > > > Lynn, > If others want, I will take this thread off line. > > I already understood most of what you have related. Just what you were > referring to as the stud and the eye was not clear to me. I am > also not > clear on just what and how much remains outside of the hole. I was > thinking > you were somehow inserting the crimped portion containing the > junction into > the hole. I am now thinking you leave the crimped junction > outside of the > hole while threading the screw through the eye or ring of a > terminal and > into the hole. Will this not leave the actual sensor junction just > above > the head and then therefore depending on the heat transfer from the > eye and > terminal to the junction? Does this not leave the actual terminal > end and > the enclosed junction to remain in the air just above the head? > This seems > to be different than my son's bayonet sensor which as I remember > inserts > into a hole in his IO360 on his RV8 which is also about to fly. I > have just > spent most of the last two days bucking rivets with him as he > finish closing > his wings. We are about to take his plane out to my hangar for a > coming > first flight. > > I am concerned that if I make use of the holes as you are when > making my > first flights, I will not know if my CHT's readings are too high or > low. > Since you are further along in this, maybe you will have > established the > correct temperature thresholds. > > The computer interface has taken me a long time to get working and > while it > is nearly there and generally working on my bench, it is not yet > complete. > It is another whole discussion which I will share either when I am > just a > bit more finished, or as the group has interest. In my post to > which you > have replied, I meant to say "as you have been experimenting, I > have been > experimenting." You did seem to get my meaning, though. > > Jim Crowder > Kitfox 5 > 3300 Jabiru Engine > >> -----Original Message----- >> From: owner-jabiruengine-list-server@matronics.com >> [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of >> Lynn >> Matteson >> Sent: Sunday, September 28, 2008 3:36 PM >> To: jabiruengine-list@matronics.com >> Subject: Re: JabiruEngine-List: CHT probe placement >> >> >> >> >> If you go to the hardware store or auto parts store, and look for the >> electrical terminals, you will see that there are red, blue and >> yellow-colored terminals for wiring. The red ones are for wire sizes >> 22 to 18, the blue are for 16-14, I believe, and the yellows are for >> wire sizes 12 to 10 as I recall. The colors are the colors of the >> insulating sleeves that are fitted to the wire entry hole. That seems >> to be industry-wide color coding. The other sizing is the size of the >> eye, so a #8 stud size will fit over a #8 stud, or a #8 screw will go >> through the hole. When I said a "#8 stud size" that means a #8 screw >> will bolt the terminal to the head in this case. If you had a large >> wire, like a #10 wire, you would look for a #8 (in this case) for the >> hole size, but a #10 wire size. There are blade terminals, open eye >> terminals, and spade terminals, and possibly others, and this refers >> to the shape of the terminal where it makes a mechanical attachment >> to whatever you are fastening the wire to. >> >> In the case of your 1/8" hole in your head, that is close to the size >> needed to tap it to 8-32. The 8-32 tap calls for a #29 drill for the >> tap to work properly. A #29 drill measures .136", so you would want >> this size hole in your head to properly tap the hole with an 8-32 >> tap. If your hole is only 1/8" or .125", you will need to drill to . >> 136" or the tap will probably break from trying to force it to go >> into a hole that is too small. I have not checked with GR, preferring >> to just drill to the size needed for the 8-32 tap. Remember, I had no >> holes in my head, and needed to drill my own holes. I understand that >> some heads are already drilled, and it was Peter Disher's post >> regarding the already-drilled heads that led me to try this >> thermocouple placement on my heads. >> >> Your interfacing sounds like a great way to record data, Jim...wish I >> was more computer oriented, but a pencil and paper work for me, >> although I'm sure I miss a LOT of data. >> >> Lynn Matteson >> Kitfox IV Speedster >> Jabiru 2200, 562 hrs, and counting...all systems are go. >> >> >> On Sep 28, 2008, at 1:28 PM, Jim Crowder wrote: >> >>> >>> >>> Just what is a "#8 stud size, eye terminal." A picture of this >>> would be a >>> help to me. I have the 3300 and my engine has the small holes. I >>> have not >>> measured them precisely, but as I remember a 1/8" drill will fit >>> inside. I >>> also have the Grand Rapids EIS. I have been following your saga >>> with great >>> interest. Have you checked with GR to see if they might now offer >>> a sensor >>> that might fit or be more adaptable to the hole? >>> >>> As you have been experimenting with a small daylight readable >>> screen HP >>> tablet computer which I have interfaced to the GR EIS. I have >>> programmed >>> Excel spreadsheet to graphically display the output from the EIS. >>> I will >>> post pictures of all of this soon. I have also built my own >>> cowling for my >>> Kitfox 5 and then more recently greatly modified the lower cowl to >>> increase >>> the exit area and greatly modify the exit lip to hopefully increase >>> the >>> negative air pressure to further aid cooling. I did this without >>> even >>> checking the first version after all of the comments regarding >>> cooling. I >>> will also send pictures of this soon. My engine has yet to run, >>> but in the >>> next two months I hope to have all together. >>> >>> Jim Crowder >>> >>>> -----Original Message----- >>>> From: owner-jabiruengine-list-server@matronics.com >>>> [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of >>>> Lynn >>>> Matteson >>>> Sent: Sunday, September 28, 2008 7:05 AM >>>> To: jabiruengine-list@matronics.com >>>> Subject: Re: JabiruEngine-List: CHT probe placement >>>> >>>> >>>> Here ya go, Tex. I had to grind a bit off the fins just above the >>>> area, then level out the little hump, and it was clear sailing to >>>> drill it and tap it with an 8-32 tap. I just cut the old 12mm >>>> terminal off the t'couple lead, bared the leads a bit, shrink tubed >>>> them right up to the bare area and inserted them into a new #8 stud >>>> size, eye terminal. Where the leads contact each other is where the >>>> temp reading actually takes place, so be sure to shove the bare >>>> leads >>>> right up to the terminal before crimping. At least that's how this >>>> anal reporter did/does it. : ) >>>> >>>> >>>> Lynn Matteson >>>> Kitfox IV Speedster >>>> Jabiru 2200, 562 hrs, and counting...all systems are go. >>>> >>>> >>>> >>> >>> >>> >>> >>> >> >> >> >> >> > > ________________________________ Message 8 _____________________________________ Time: 09:45:18 PM PST US From: "Craig Payne" Subject: RE: JabiruEngine-List: CHT probe placement Temporarily install a thermocouple under the plug and in your new hole. That will allow you to build a conversion chart. -- Craig ________________________________ Message 9 _____________________________________ Time: 11:22:01 PM PST US From: "Jim Crowder" Subject: RE: JabiruEngine-List: CHT probe placement Lynn, I now understand. Unless I am confident of where I am going with this, I am reluctant to drill into my head as Peter did. Has Peter reported the temperatures he is getting, or is he not flying yet? I should think your temperatures would be similar to what others get with the rings under the head bolts if they allow the sensor to lie flat upon the head. There is a paste that could also be placed under the terminal that enhances heat conduction. It is used with heat sinks, etc. I do not know the operating temperature of it. I just looked at my temperature probes and I could cut the end portion of the rings so as to remove a horseshoe shaped portion of the ring and leave a spade like flat remainder that I could easily drill for a #8 screw. That way I believe I would not need to remove the old terminal and still get the same result. Did you consider that or were your sensors different? I have copied my Excel display screen to a Word document and I will attempt to post by attaching hereto. On the display you will see the graph with inserted values except for CHT which were actual values from my GR instrument with the sensors attached and I had heated them with a heat gun while held in a cluster by hand. When the snapshot was taken they had cooled down to below normal operating temperature. They are all displayed in red as I had set the program to display red when above or below the safe operational range. If above safe temperature they would also display red. Yellow is for near high or low and green is for the optimum range. It is really fun to watch them change colors and move up and down as I apply heat or remove it. These ranges are set by typing the various numbers into the spreadsheet at setup. I do not have rate of cooling programmed yet. My Tablet Computer is very flat and has only a 12" diag. display. In use I will mount it on my instrument panel and the display I have attached will take up one half of the display with Vista GPS driven moving chart taking up the other half. I have tried this in my car and boat and it works nicely. Note the fuel flow is red as such a flow would indicate a problem. The same for the cooling rate which is not now truly functional yet. This should work on any laptop with my software and interface. I have spent way too much time on this. I will be interested to see if the attached file goes through. If not I will send it directly to you. Jim Crowder Kitfox 5 Jabiru 3300 engine > -----Original Message----- > From: owner-jabiruengine-list-server@matronics.com > [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of Lynn > Matteson > Sent: Sunday, September 28, 2008 10:36 PM > To: jabiruengine-list@matronics.com > Subject: Re: JabiruEngine-List: CHT probe placement > > > > > Yes, I use the hole that I drilled for the screw, and the crimped > portion lays parallel to the head and very close to the surface..as > close as a few thousandths from it....as close as the screw can clamp > it to the surface. You could also do as you say, or suggest, cut off > the eye and insert the crimped portion right into the hole if you > could come up with a suitable way to retain it there. That may be how > Peter Disher did his..see the archives from Aug 25, 2008 from this > List...he has pictures there. I just forwarded this post to you. It > *does* sound like he inserted the bare wires perhaps, right into the > hole, then ran the screw into the hole. I suppose you could tap the > hole, then maybe rout a small groove on one side of the hole in which > to insert the bare wires of the t'couple. In any case, the closer to > the head, or even right into it, the more accurate the reading. What > we are dealing with here however is "uncharted waters", in that > because no one else has done this, or reported their findings, we > don't know just what the readings should be. That's where the pucker > factor for my first flight came from. > I was quick to get the plane off the ground, thinking that I'd better > get it up there and get cooler air flowing over the engine. I was > thinking that my seemingly elevated temps were the result of the > newly honed cylinders and new piston rings causing high friction, but > it was the more accurate readings of the t'couple probe placement > that revealed the higher temps. So what IS the proper temp, now that > we have the more accurate readings....beats me!! Maybe Jabiru knows. > For me, I just tried to keep it below their posted max of 392 F, but > it did go over that once, on the initial startup, running it on the > ground. That's why I quickly got it into the air, and that act almost > bit me in the butt. The tight engine wasn't climbing very well, so I > kept it above tree level, climbing slightly and getting it turned > around and landed. When I realized that the engine didn't feel any > hotter than before, I started to realize that the feel of the engine > was the same as before, but the readings were higher because the > probe was no longer 1/2" away from the head, up into the airstream, > being cooled and giving lower but inaccurate readings of the actual > temp of the head. This is all fine and good if we all do it just the > way Jabiru does it, with the spark plug probes. So I unpuckered, and > began to accept that I would now be seeing 350-380 F as the > norm....my norm, instead of the 275 of before. I guess this is where > the "experimenting" part comes in. : ) > > I flew to an airport about 40 miles away today, and my head temps > were running about 358 for the most part, and I've accepted that as > my new norm. It comforts me to know that I haven't changed anything > relating to airflow, so I'm accepting the higher readings as being > "normal." > > I also wish that Jabiru would give us a socket for a bayonet sensor, > or at least report what such a probe placement would reveal in the > way of temps. > > Yes, I kind of read between the lines on your experimenting, and > please do keep *us all* posted on your progress....I'm sure that this > is the kind of thing that this List is meant to do...inform and share > all aspects of Jabiru engine-related experimentation. At least that's > the way I read it. > > > Lynn Matteson > Kitfox IV Speedster > Jabiru 2200, 562 hrs, and counting...all systems are go, or nearly so... ________________________________ Message 10 ____________________________________ Time: 11:41:04 PM PST US From: "Jim Crowder" Subject: RE: JabiruEngine-List: CHT probe placement For myself, I thought of that, but it would add another issue to a first flight and my displays would be confusing with incorrect labeling. It might be a thing to do later. Anyway, I am hoping someone else will have done that for me. ;>) Jim Crowder > -----Original Message----- > From: owner-jabiruengine-list-server@matronics.com > [mailto:owner-jabiruengine-list-server@matronics.com]On Behalf Of Craig > Payne > Sent: Sunday, September 28, 2008 10:45 PM > To: jabiruengine-list@matronics.com > Subject: RE: JabiruEngine-List: CHT probe placement > > > > > Temporarily install a thermocouple under the plug and in your new > hole. That > will allow you to build a conversion chart. > > -- Craig > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message jabiruengine-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/JabiruEngine-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/jabiruengine-list Browse Digests http://www.matronics.com/digest/jabiruengine-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.