---------------------------------------------------------- RV-List Digest Archive --- Total Messages Posted Tue 07/26/05: 32 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:04 AM - Re: first flight (RAS) 2. 04:32 AM - Re: OAT Probe location (Stewart, Michael (ISS Atlanta)) 3. 05:08 AM - Re: OAT Probe location (rveighta) 4. 05:09 AM - Re: OAT Probe location (Alex Peterson) 5. 06:07 AM - Re:engine break- in / no fairings (Dale Ensing) 6. 07:33 AM - Re: OAT Probe location (Jeff Dowling) 7. 07:34 AM - Injector Balancing (Chuck Jensen) 8. 08:15 AM - Re: Injector Balancing (Scott Bilinski) 9. 08:55 AM - Re: OAT Probe location (sportav8r@aol.com) 10. 08:59 AM - Re: OAT Probe location (sportav8r@aol.com) 11. 09:37 AM - Need FAR update - pitot-static, transponder in VFR (Knicholas2@aol.com) 12. 10:16 AM - Re: Need FAR update - pitot-static, transponder in VFR (Chuck Jensen) 13. 10:48 AM - Re: first flight (Hull, Don) 14. 10:52 AM - Re: first flight (GMC) 15. 10:57 AM - Re: Need FAR update - pitot-static, transponder in VFR (sportav8r@aol.com) 16. 11:14 AM - Re: Need FAR update - pitot-static, transponder in VFR (Ron Lee) 17. 12:29 PM - Re: OAT Probe location (Chris W) 18. 01:07 PM - Re: Need FAR update - pitot-static, transponder in VFR (Dale Ensing) 19. 01:25 PM - Re: first flight (Sam Buchanan) 20. 01:36 PM - Re: Need FAR update - pitot-static, transponder in VFR (Ed Bundy) 21. 01:51 PM - Re: OAT Probe location (BELTEDAIR@aol.com) 22. 02:09 PM - Re: first flight (linn walters) 23. 03:16 PM - Re: first flight (Sam Buchanan) 24. 04:10 PM - Re: OAT Probe location (Kevin Horton) 25. 05:43 PM - () 26. 06:07 PM - Re: OAT Probe location "as it relates to cabin cooling" (Bill Schlatterer) 27. 06:17 PM - Re: first flight (Alex Peterson) 28. 06:51 PM - Re: first flight (Jerry Springer) 29. 07:23 PM - fresh engines and new airplanes (Sam Buchanan) 30. 08:07 PM - Re: fresh engines and new airplanes (Darrell Reiley) 31. 08:18 PM - Re: first flight (JOHN STARN) 32. 08:42 PM - Re: first flight (Jerry Springer) ________________________________ Message 1 _____________________________________ Time: 02:04:28 AM PST US From: "RAS" Subject: Re: RV-List: first flight --> RV-List message posted by: "RAS" Hi, It is in the Van's manual. Marcel ----- Original Message ----- From: "Alex Peterson" Subject: RE: RV-List: first flight > --> RV-List message posted by: "Alex Peterson" > > > >> I seriously suffer from RVgrin, we broke through the magic 200MPH this >> afternoon on the second flight. This is without wheelpants or leg >> fairings. >> It is recommended to fly without if you use factory new engines. > > Why? It seems like one would want to run the engine as cool as possible > when breaking it in. Flying without fairings will run the engine hotter. > > Alex Peterson > RV6A N66AP 641 hours > Maple Grove, MN > > > ________________________________ Message 2 _____________________________________ Time: 04:32:15 AM PST US Subject: RE: RV-List: OAT Probe location From: "Stewart, Michael (ISS Atlanta)" --> RV-List message posted by: "Stewart, Michael (ISS Atlanta)" Anywhere in the wing root works. Mine just hang in there strapped to a wire bundle NACA inlet was 8degF high for me too. Mike Do not archive -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of rveighta Subject: RV-List: OAT Probe location --> RV-List message posted by: rveighta Guys, when I was finishing up my RV-8A, I placed the OAT probe in the NACA air duct. Never been happy with it -temps run too hot. Now that I'm in the same building spot with my rv-8 I'm wondering where a better location might be? Maybe in the leading edge of the wing/fuselage fairing? Appreciate any ideas...... Walt Shipley ________________________________ Message 3 _____________________________________ Time: 05:08:30 AM PST US From: rveighta Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: rveighta Terry, I put mine in the left NACA vent and it runs around 10 degrees too hot. Walt -----Original Message----- From: Terry Watson Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: "Terry Watson" Walt, As you know but other builders might not, the 8 & 8A have two NACA vents, one in the fuselage and one in the bottom of the right wing. It has always seemed to me that the one in the right wing would be a good place for the OAT probe, so that's the direction I have run my probe wires. Which one did you install it in in your 8A? Terry RV-8A finishing? Seattle -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of rveighta Subject: RV-List: OAT Probe location --> RV-List message posted by: rveighta Guys, when I was finishing up my RV-8A, I placed the OAT probe in the NACA air duct. Never been happy with it -temps run too hot. Now that I'm in the same building spot with my rv-8 I'm wondering where a better location might be? Maybe in the leading edge of the wing/fuselage fairing? Appreciate any ideas...... Walt Shipley ________________________________ Message 4 _____________________________________ Time: 05:09:59 AM PST US From: "Alex Peterson" Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: "Alex Peterson" > Mine is in the NACA inlet and reads 8-10 deg C high. > Worthless location. > > Ron Lee Just as another data point, mine is also in the NACA inlet, and reads dead on in all conditions (thermistor based system). I think many of the errors people see with NACA located temperature probes have to do with the location of the reference junction (in the case of thermocouple based systems) or from heat conducting out through the wiring to the unit from underneath the panel. Even while idling in hot weather, my unit reads within 1 degree of what the ATIS reads, and has done so consistently for four years. In flight I see the same readings that others flying with me with probes in all sorts of locations see. That is a big breeze blowing by from the prop compared to leaks of hot air coming from the cowl hinges. Something other than those leaks is causing the majority of the errors, IMO. Alex Peterson RV6A N66AP 641 hours Maple Grove, MN ________________________________ Message 5 _____________________________________ Time: 06:07:53 AM PST US From: "Dale Ensing" Subject: RV-List: Re:engine break- in / no fairings --> RV-List message posted by: "Dale Ensing" Hi Alex, It is recommended by Van and engine books/people to create drag and therefore load on the engine during break-in. All the while watching the temps of course. Dale Ensing ________________________________ Message 6 _____________________________________ Time: 07:33:46 AM PST US From: "Jeff Dowling" Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: "Jeff Dowling" I put mine in the gear leg intersection fairing between the gear leg and wing. Is pretty inconspicuous and seems to work fine. I coiled the extra cable inside the fairing which makes it easy to remove. Shemp/Jeff Dowling RV-6A, N915JD 220 hours Chicago/Louisville ----- Original Message ----- From: "rveighta" Subject: RV-List: OAT Probe location > --> RV-List message posted by: rveighta > > Guys, when I was finishing up my RV-8A, I placed the OAT probe in the NACA > air duct. Never been happy with it -temps run too hot. Now that I'm in the > same building spot with my rv-8 I'm wondering where a better location > might be? Maybe in the leading edge of the wing/fuselage fairing? > > Appreciate any ideas...... > > Walt Shipley > > > ________________________________ Message 7 _____________________________________ Time: 07:34:13 AM PST US Subject: RV-List: Injector Balancing From: "Chuck Jensen" --> RV-List message posted by: "Chuck Jensen" Anyone have a reference or recommendation for a shop that does injector balancing, in this case for an IO-540 (in a Velocity, not RV or HRII). I went through the process with GAMI but they ended up at a dead end. One cylinder's injector was limit rich and another was limit lean, but the spread was still above 1.5 gph...this after checking induction, valve train lashing, spider, et al. GAMI says its 'unusual' but not unheard of, even though there is nothing specifically wrong with the engine. So, I'm looking for a shop that I can go to that will put hands-on to double check everything and come up with an injector solution. Currently, I run with 2 cylinders LOP and the other 4 ROP (per GRT EIS/EFIS). It works but it's not right. Suggestions? Chuck ________________________________ Message 8 _____________________________________ Time: 08:15:08 AM PST US From: Scott Bilinski Subject: Re: RV-List: Injector Balancing --> RV-List message posted by: Scott Bilinski Air Flow Performance can make the injector nozzles for you, I would think. They made some custom ones for me, I think they were about 15 bucks a piece. They have a flow bench which means they can make anything you need. http://www.airflowperformance.com/ At 10:32 AM 7/26/2005 -0400, you wrote: >--> RV-List message posted by: "Chuck Jensen" > > >Anyone have a reference or recommendation for a shop that does injector >balancing, in this case for an IO-540 (in a Velocity, not RV or HRII). >I went through the process with GAMI but they ended up at a dead end. >One cylinder's injector was limit rich and another was limit lean, but >the spread was still above 1.5 gph...this after checking induction, >valve train lashing, spider, et al. GAMI says its 'unusual' but not >unheard of, even though there is nothing specifically wrong with the >engine. > >So, I'm looking for a shop that I can go to that will put hands-on to >double check everything and come up with an injector solution. >Currently, I run with 2 cylinders LOP and the other 4 ROP (per GRT >EIS/EFIS). It works but it's not right. Suggestions? > >Chuck > > Scott Bilinski Eng dept 305 Phone (858) 657-2536 Pager (858) 502-5190 ________________________________ Message 9 _____________________________________ Time: 08:55:07 AM PST US From: sportav8r@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: sportav8r@aol.com Agree. My installation (RV-6A) suffers the same drawbacks. I did some experimentation awhile back (should be in the archives) which demonstrated that part of the temp rise was from conducted heat through the cowl (boundary-layer air picking up heat by passing over the cowl) and part was actual leakage of heated air through the piano hinge junction between upper and lower cowl halves. What REALLY peeved me was the realization that no only were my OAT's artificially high and therefore almost worthless, but that the vent air I was relying on for cockpit cooling was being bumped up about 8 degrees F over what should be available from adiabatic cooling at altitude. Pilot and passenger comfort was suffering (and still does). There is no easy way to plumb fresh air to an RV cockpit that avoids both pre-heating and CO risk... there are ways, but no easy ones that I can see. At least the wiring of an OAT probe in a suitable location is not as much of a hassle as routing long len gths of SCAT from a wing. -Stormy -----Original Message----- From: Ron Lee Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Ron Lee Mine is in the NACA inlet and reads 8-10 deg C high. Worthless location. Ron Lee ________________________________ Message 10 ____________________________________ Time: 08:59:31 AM PST US From: sportav8r@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: sportav8r@aol.com My experimentation included reading OAT from an independent, remote thermometer mounted outside under the wing for one flight, and in the outlet for cabin cooling air for another flight. It's not just heat seeping into the thermistor probe in the NACA inlet (which has no "reference junction," by the way, since it is not a thermocouple), as mine is amply insulated from the rear with expandable urethane foam insulation... the air coming out of the freash air vent is actually a measured 8 degrees F hotter than ambient. It's a sad but true data point. -Stormy -----Original Message----- From: Alex Peterson Subject: RE: RV-List: OAT Probe location --> RV-List message posted by: "Alex Peterson" > Mine is in the NACA inlet and reads 8-10 deg C high. > Worthless location. > > Ron Lee Just as another data point, mine is also in the NACA inlet, and reads dead on in all conditions (thermistor based system). I think many of the errors people see with NACA located temperature probes have to do with the location of the reference junction (in the case of thermocouple based systems) or from heat conducting out through the wiring to the unit from underneath the panel. Even while idling in hot weather, my unit reads within 1 degree of what the ATIS reads, and has done so consistently for four years. In flight I see the same readings that others flying with me with probes in all sorts of locations see. That is a big breeze blowing by from the prop compared to leaks of hot air coming from the cowl hinges. Something other than those leaks is causing the majority of the errors, IMO. Alex Peterson RV6A N66AP 641 hours Maple Grove, MN ________________________________ Message 11 ____________________________________ Time: 09:37:10 AM PST US From: Knicholas2@aol.com Subject: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: Knicholas2@aol.com Ok, I am having a brain cramp. I know that for IFR, the pitot-static system and transponder have to be calibrated and certified every 24 months. Does this have to be done for strictly VFR flying? Kim Nicholas RV9A ________________________________ Message 12 ____________________________________ Time: 10:16:23 AM PST US Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR From: "Chuck Jensen" --> RV-List message posted by: "Chuck Jensen" Nope. For VFR, you just need an engine and two wings. Need a radio to go into Class C and D and a radio/transponder into Class B. Chuck -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Knicholas2@aol.com Subject: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: Knicholas2@aol.com Ok, I am having a brain cramp. I know that for IFR, the pitot-static system and transponder have to be calibrated and certified every 24 months. Does this have to be done for strictly VFR flying? Kim Nicholas RV9A ________________________________ Message 13 ____________________________________ Time: 10:48:52 AM PST US From: "Hull, Don" Subject: RE: RV-List: first flight --> RV-List message posted by: "Hull, Don" I think there may be a misunderstanding here...he was talking about wheel pants and leg fairings, not the cowling. The engine probably would run hot without the cowling...I know on the ground it would. But flying without wheel fairings shouldn't affect the engine temperatures significantly. Don Hull -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Alex Peterson Subject: RE: RV-List: first flight --> RV-List message posted by: "Alex Peterson" --> > I seriously suffer from RVgrin, we broke through the magic 200MPH this > afternoon on the second flight. This is without wheelpants or leg > fairings. It is recommended to fly without if you use factory new > engines. Why? It seems like one would want to run the engine as cool as possible when breaking it in. Flying without fairings will run the engine hotter. Alex Peterson RV6A N66AP 641 hours Maple Grove, MN ________________________________ Message 14 ____________________________________ Time: 10:52:52 AM PST US From: GMC Subject: Re: RV-List: first flight --> RV-List message posted by: GMC Yes it is, see RV-6 manual page 15-4 George in Langley BC Do not archive RAS wrote: >Hi, > >It is in the Van's manual. > >Marcel > > > >>>I seriously suffer from RVgrin, we broke through the magic 200MPH this >>>afternoon on the second flight. This is without wheelpants or leg >>>fairings. >>>It is recommended to fly without if you use factory new engines. >>> >>> >>Why? It seems like one would want to run the engine as cool as possible >>when breaking it in. Flying without fairings will run the engine hotter. >> >> >> ________________________________ Message 15 ____________________________________ Time: 10:57:30 AM PST US From: sportav8r@aol.com Subject: Re: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: sportav8r@aol.com I believe if you have a transponder in the plane, it's supposed to be "on" whenever in flight,and if it's being used, the calibration is also a requirement (the static/encoder part, anyway). Having the transponder is optional, but using it if you have it isn't. Others will no doubt correct that idea if it's wrong. -Stormy -----Original Message----- From: Chuck Jensen Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Chuck Jensen" Nope. For VFR, you just need an engine and two wings. Need a radio to go into Class C and D and a radio/transponder into Class B. Chuck -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com] On Behalf Of Knicholas2@aol.com Subject: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: Knicholas2@aol.com Ok, I am having a brain cramp. I know that for IFR, the pitot-static system and transponder have to be calibrated and certified every 24 months. Does this have to be done for strictly VFR flying? Kim Nicholas RV9A ________________________________ Message 16 ____________________________________ Time: 11:14:14 AM PST US From: Ron Lee Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: Ron Lee No time to look it up but I suspect that if you USE a transponder it needs to be checked. Ron Lee ________________________________ Message 17 ____________________________________ Time: 12:29:57 PM PST US From: Chris W <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Chris W <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> sportav8r@aol.com wrote: >... the air coming out of the freash air vent is actually a measured 8 degrees F hotter than ambient. > Really?! Out of curiosity, what air speed was that measurement taken at? -- Chris W Gift Giving Made Easy Get the gifts you want & give the gifts they want http://thewishzone.com ________________________________ Message 18 ____________________________________ Time: 01:07:18 PM PST US From: "Dale Ensing" Subject: Re: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Dale Ensing" Kim, If you are asking about a Mode C transponder, yes the altitude reporting must be checked/calibrated every two years by a certified technician? If not mode C, I think the effective output of the transponder must still be checked for position reporting. Dale Ensing ________________________________ Message 19 ____________________________________ Time: 01:25:26 PM PST US From: Sam Buchanan Subject: Re: RV-List: first flight --> RV-List message posted by: Sam Buchanan Hull, Don wrote: > --> RV-List message posted by: "Hull, Don" > > I think there may be a misunderstanding here...he was talking about wheel > pants and leg fairings, not the cowling. The engine probably would run hot > without the cowling...I know on the ground it would. But flying without > wheel fairings shouldn't affect the engine temperatures significantly. > Don Hull As I understand the deal, the reason for flying without wheelpants and fairings when testing a new RV with a new engine is so the engine can be broken in properly. Most engine-types agree that the best way to seat the piston rings is with the use of high rpm under light load. The point is to get rpm up while keeping CHT's down. This allows the rings to "scuff-in" without heat-stressing the cylinders. This is also the reason that some engine manuals suggest periods of high rpm interspersed with lower rpm to prevent the cylinders from overheating. However, if this routine if followed with a brand new RV with all fairings installed, the pilot will quickly find himself operating the plane way up in the speed range. This is not good for the first few flights! Airspeed should be gradually increased during subsequent flights as the airframe is proven to have no problems with high airspeed. So the requirements of a new engine and a new airframe have opposing goals. The best way to run the engine at high rpm and keep airspeed down is to fly without wheelpants and fairings. By the way, an RV that can hit 200mph in level flight without wheelpants and fairings is a very impressive RV!!!! ;-) Sam Buchanan ========================= > > -----Original Message----- > From: owner-rv-list-server@matronics.com > [mailto:owner-rv-list-server@matronics.com] On Behalf Of Alex Peterson > To: rv-list@matronics.com > Subject: RE: RV-List: first flight > > > --> RV-List message posted by: "Alex Peterson" > --> > > >>I seriously suffer from RVgrin, we broke through the magic 200MPH this >>afternoon on the second flight. This is without wheelpants or leg >>fairings. It is recommended to fly without if you use factory new >>engines. > > > Why? It seems like one would want to run the engine as cool as possible > when breaking it in. Flying without fairings will run the engine hotter. > > Alex Peterson > RV6A N66AP 641 hours > Maple Grove, MN > ________________________________ Message 20 ____________________________________ Time: 01:36:39 PM PST US From: "Ed Bundy" Subject: RE: RV-List: Need FAR update - pitot-static, transponder in VFR --> RV-List message posted by: "Ed Bundy" This is one of the most misunderstood areas that I run into when giving a BFR. You *absolutely* need a transponder w/mode C to operate in Class C airspace. Also to operate above Class B or C within the lateral boundaries. Also required within 30nm of a Class B airport even outside the B airspace (the "veil"). Also necessary above 10,000' MSL everywhere. (unless at or below 2500 agl) There are a lot of places you can't go without a mode C transponder, but you don't HAVE to have one. If you do have one, you don't have to use it if not in the above mentioned airspace. However, if you do have one, and you do use it, it has to have been checked within the preceding 2 years. There is no pitot-static test requirement for VFR flight. Ed Bundy --> RV-List message posted by: "Chuck Jensen" Nope. For VFR, you just need an engine and two wings. Need a radio to go into Class C and D and a radio/transponder into Class B. --> RV-List message posted by: Knicholas2@aol.com Ok, I am having a brain cramp. I know that for IFR, the pitot-static system and transponder have to be calibrated and certified every 24 months. Does this have to be done for strictly VFR flying? -- ________________________________ Message 21 ____________________________________ Time: 01:51:52 PM PST US From: BELTEDAIR@aol.com Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: BELTEDAIR@aol.com The temp rise may well be from air exiting the cowl openings and flowing back along the fuselage to your air pickup. We relocated ours on top of the fuselage aft of the antenna, aft of the slider limit. The inlets are oversized for climb cooling. Jess Belted Air ________________________________ Message 22 ____________________________________ Time: 02:09:30 PM PST US From: linn walters Subject: Re: RV-List: first flight --> RV-List message posted by: linn walters Much as I hate to disagree with Sam, I'd like to make some points. First, the best way to seat the rings is to get max pressure in the cylinder. The rings aren't flat, and the high pressure forces the ring to 'flatten' a little and thus seal better. That's as I understand it. High RPMs aren't necessarily a requirement as much as a by-product of the high pressures in the cylinder (which equates to more power) and may be controlled by cranking in the pitch on a CS prop. On a FP prop, the only thing you can do to keep the engine somewhat under redline (depending on the pitch, of course) is to increase drag, which is (I'm guessing here) why removal of the pants and gear fairings are suggested. There is a caveat here. One of the byproducts of max power is heat, and you should keep a close eye on the CHTs to prevent cooking the cylinders. This means good baffling and enough airflow to keep max CHTs in the 400 range. Oil temps are important to monitor also and should be in the 170 to 220 (F) range. I run the crap out of my O-360 in my Pitts ...... and I see 3200-3300 a lot. My oil temps stay at the low end, 170 to 180 deg F. I don't know what the CHTs or EGTs do (no instrumentation) so maybe ignorance is bliss. What I did when breaking in the engine ..... the first and second times ..... was full power leaned at something around 3000 ASL and all cylinders (steel rings, chrome cylinders) seated in short time .... about 8 hours. Hard to judge oil consumption since a lot is lost through the inverted oil system and vent when doing really unusual attitudes. Hope this helps, rather than confuse! :-P Linn do not archive Sam Buchanan wrote: >--> RV-List message posted by: Sam Buchanan > >Hull, Don wrote: > > >>--> RV-List message posted by: "Hull, Don" >> >>I think there may be a misunderstanding here...he was talking about wheel >>pants and leg fairings, not the cowling. The engine probably would run hot >>without the cowling...I know on the ground it would. But flying without >>wheel fairings shouldn't affect the engine temperatures significantly. >>Don Hull >> >> > > >As I understand the deal, the reason for flying without wheelpants and >fairings when testing a new RV with a new engine is so the engine can be >broken in properly. Most engine-types agree that the best way to seat >the piston rings is with the use of high rpm under light load. The point >is to get rpm up while keeping CHT's down. This allows the rings to >"scuff-in" without heat-stressing the cylinders. This is also the reason >that some engine manuals suggest periods of high rpm interspersed with >lower rpm to prevent the cylinders from overheating. > >However, if this routine if followed with a brand new RV with all >fairings installed, the pilot will quickly find himself operating the >plane way up in the speed range. This is not good for the first few >flights! Airspeed should be gradually increased during subsequent >flights as the airframe is proven to have no problems with high airspeed. > >So the requirements of a new engine and a new airframe have opposing >goals. The best way to run the engine at high rpm and keep airspeed down >is to fly without wheelpants and fairings. > >By the way, an RV that can hit 200mph in level flight without wheelpants >and fairings is a very impressive RV!!!! ;-) > >Sam Buchanan > >========================= > > >>-----Original Message----- >>From: owner-rv-list-server@matronics.com >>[mailto:owner-rv-list-server@matronics.com] On Behalf Of Alex Peterson >>To: rv-list@matronics.com >>Subject: RE: RV-List: first flight >> >> >>--> RV-List message posted by: "Alex Peterson" >>--> >> >> >> >> >>>I seriously suffer from RVgrin, we broke through the magic 200MPH this >>>afternoon on the second flight. This is without wheelpants or leg >>>fairings. It is recommended to fly without if you use factory new >>>engines. >>> >>> >>Why? It seems like one would want to run the engine as cool as possible >>when breaking it in. Flying without fairings will run the engine hotter. >> >>Alex Peterson >>RV6A N66AP 641 hours >>Maple Grove, MN >> >> >> > > > > ________________________________ Message 23 ____________________________________ Time: 03:16:58 PM PST US From: Sam Buchanan Subject: Re: RV-List: first flight --> RV-List message posted by: Sam Buchanan linn walters wrote: > --> RV-List message posted by: linn walters > > Much as I hate to disagree with Sam, I'd like to make some points. > First, the best way to seat the rings is to get max pressure in the > cylinder. The rings aren't flat, and the high pressure forces the ring > to 'flatten' a little and thus seal better. That's as I understand it. > High RPMs aren't necessarily a requirement as much as a by-product of > the high pressures in the cylinder (which equates to more power) and may > be controlled by cranking in the pitch on a CS prop. On a FP prop, the > only thing you can do to keep the engine somewhat under redline > (depending on the pitch, of course) is to increase drag, which is (I'm > guessing here) why removal of the pants and gear fairings are > suggested. There is a caveat here. One of the byproducts of max power > is heat, and you should keep a close eye on the CHTs to prevent cooking > the cylinders. This means good baffling and enough airflow to keep max > CHTs in the 400 range. Oil temps are important to monitor also and > should be in the 170 to 220 (F) range. Linn, I think we are saying the same thing. Run the engine hard, keep the cylinders from getting too hot, and fly without fairings to keep airspeed in a reasonable range. Sam Buchanan ________________________________ Message 24 ____________________________________ Time: 04:10:36 PM PST US From: Kevin Horton Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Kevin Horton On 26 Jul 2005, at 15:27, Chris W wrote: > --> RV-List message posted by: Chris W > <1qazxsw23edcvfr45tgbnhy67ujm@cox.net> > > sportav8r@aol.com wrote: > > >> ... the air coming out of the freash air vent is actually a >> measured 8 degrees F hotter than ambient. >> >> > Really?! Out of curiosity, what air speed was that measurement > taken at? > I'd also be interested to know how one measures the ambient temperature so one can compare the output of the temp sensor to ambient. At 170 kt TAS, the temperature increase due to ram rise would be about 7 deg F. I.e, if you took the air coming in the NACA scoop, and let it slow down so it is at rest with respect to the aircraft, you would expect its temperature to be about 7 deg F hotter than the ambient temperature. Just be glad you aren't racing for the Unlimited Gold at Reno. At the speeds those guys are running, the ram rise would be over 45 deg F, and the ambient temperature is already pretty hot. The ram rise in deg C is equal to the square of the TAS in kt divided by 7592. The ram rise in deg F is equal to the square of the TAS in mph divided by 5587. The amount of the ram rise sensed by the temperature sensor will vary, depending on the probe's recovery factor. Good quality probes supposedly have recovery factors of between 0.95 and 1, but some probes may have lower recovery factors. The temperature measured by the probe would be about: IAT=OAT+K*(TAS 2/7592) where IAT is the indicated air temperature reported by the probe, in deg C OAT is the actual ambient air temperature, in deg C, K is the probe's recovery factor, and TAS is the true airspeed in kt You may be more familiar with the classical equation that relates ram rise to Mach. total air temperature/ambient air temperature = (1 + 0.2 * M 2), with both temperatures expressed in either degrees Kelvin, or degrees Rankin). Or, OAT = (IAT + 273.15) / (1 + 0.2*K*M 2) - 273.15 where where IAT is the indicated air temperature reported by the probe, in deg C, OAT is the actual ambient air temperature, in deg C, K is the probe's recovery factor, and M is the Mach number. The first time I saw the equation with TAS, I thought it must be an approximation, as we are always told that ram rise is a function of Mach. But, one day when I was bored, I dissected the equations and found that the equation with TAS was mathematically equivalent to the one with Mach. Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 25 ____________________________________ Time: 05:43:01 PM PST US From: "" Subject: RV-List: --> RV-List message posted by: "" Linn is correct here. It's not necessarily high RPM that seats the rings, it"s high manifold pressure. The higher MP forces the rings tighter against the cylinder walls and wears them in quicker. The object is to have the rings form their best seal before a layer of varnish forms on the Cyl. walls, at which point, further ring seating effectively ceases. For this reason, you should not go to high altitudes until break in is complete. With steel or Cerminil Cyls., break in is usually complete within 1 Hr. as evidenced by a stabilized oil consumption. Bill Davis rvpilot@access4less.net --> RV-List message posted by: linn walters Much as I hate to disagree with Sam, I'd like to make some points. First, the best way to seat the rings is to get max pressure in the cylinder. The rings aren't flat, and the high pressure forces the ring to 'flatten' a little and thus seal better. That's as I understand it. ________________________________ Message 26 ____________________________________ Time: 06:07:37 PM PST US From: "Bill Schlatterer" Subject: RE: RV-List: OAT Probe location "as it relates to cabin cooling" --> RV-List message posted by: "Bill Schlatterer" Perhaps an obvious question, but if the OAT is running 8-10 degrees hot, does that infer that the air coming through the NACA duct for cabin cooling is also 8 degrees hotter than ambient. If so, other than sheer volume it would appear that a cold air intake in the front intake would be better for passenger cooling. 8-10 degrees seems like a lot of difference in an airplane without AC. Is it worth the trouble to find a "cooler" intake area for cabin air? I fly mostly in the South and it seems like cooling not heat is the issue most of the time in this area. Bill S 7a Ark -----Original Message----- From: owner-rv-list-server@matronics.com [mailto:owner-rv-list-server@matronics.com]On Behalf Of Ron Lee Subject: Re: RV-List: OAT Probe location --> RV-List message posted by: Ron Lee Mine is in the NACA inlet and reads 8-10 deg C high. Worthless location. Ron Lee ________________________________ Message 27 ____________________________________ Time: 06:17:13 PM PST US From: "Alex Peterson" Subject: RE: RV-List: first flight --> RV-List message posted by: "Alex Peterson" > > I think there may be a misunderstanding here...he was talking about wheel > pants and leg fairings, not the cowling. The engine probably would run > hot > without the cowling...I know on the ground it would. But flying without > wheel fairings shouldn't affect the engine temperatures significantly. > Don Hull Flying without the wheel and gear fairings would be like flying a shallow climb, and the engine will definitely run hotter. How much is hard to tell, but it will be more than one would think. For the same power output (and hence heat load, mixture being the same), the airspeed will be less, and therefore less cooling air with no fairings. No way around it. Those who have only flown overcooled training aircraft will have a hard time believing the sensitivity of airspeed vs cooling in RV's. The -4's seem to have quite a bit more cooling reserve than the other RV's, due in part to their higher speeds for the same power. Alex Peterson RV6A N66AP 641 hours Maple Grove, MN ________________________________ Message 28 ____________________________________ Time: 06:51:43 PM PST US From: Jerry Springer Subject: Re: RV-List: first flight --> RV-List message posted by: Jerry Springer Alex Peterson wrote: >--> RV-List message posted by: "Alex Peterson" > > > >>I think there may be a misunderstanding here...he was talking about wheel >>pants and leg fairings, not the cowling. The engine probably would run >>hot >>without the cowling...I know on the ground it would. But flying without >>wheel fairings shouldn't affect the engine temperatures significantly. >>Don Hull >> >> > >The -4's seem to have quite >a bit more cooling reserve than the other RV's, due in part to their higher >speeds for the same power. > >Alex Peterson >RV6A N66AP 641 hours >Maple Grove, MN > > > > Alex I have to disagree with that. :-) I have a hard time getting oil temps up to 160 unless it is a 90 degree day, cylinder head temps run about 300-315 degrees in my RV-6. But the biggest thing I have to disagree about is a -4 being much faster than my -6 at a given power setting. Jerry do not archive ________________________________ Message 29 ____________________________________ Time: 07:23:49 PM PST US From: Sam Buchanan Subject: RV-List: fresh engines and new airplanes --> RV-List message posted by: Sam Buchanan rvpilot@access4less.net wrote: > --> RV-List message posted by: "" > > Linn is correct here. It's not necessarily high RPM that seats the rings, it"s > high manifold pressure. The higher MP forces the rings tighter against the cylinder walls > and wears them in quicker. The object is to have the rings form their best seal before a > layer of varnish forms on the Cyl. walls, at which point, further ring seating effectively ceases. > For this reason, you should not go to high altitudes until break in is complete. With > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as evidenced by a > stabilized oil consumption. Granted. But those of us with fixed-pitch props have to resort to higher rpm in order to pull more manifold pressure. I think we are getting hung up on semantics. The point I was making is the engine should not be flown gingerly, it needs to develop a lot of power (rpm or MP, whatever your particular engine/prop requires) in order to rapidly and reliably seat the rings. You guys with the CS props can load the engine at lower rpm, us folks with the cheap props have to wind up our engines (2400-2600 rpm) to get high MP unless we are flying at sea level. That's why a lot of us fly our new planes with new engines without the pants and fairings so breaking in the cylinders won't result in higher than desired airspeed. Sam Buchanan ________________________________ Message 30 ____________________________________ Time: 08:07:13 PM PST US From: Darrell Reiley Subject: Re: RV-List: fresh engines and new airplanes --> RV-List message posted by: Darrell Reiley Sam, You are correct... Thanks for your input! Sam Buchanan wrote: --> RV-List message posted by: Sam Buchanan rvpilot@access4less.net wrote: > --> RV-List message posted by: "" > > Linn is correct here. It's not necessarily high RPM that seats the rings, it"s > high manifold pressure. The higher MP forces the rings tighter against the cylinder walls > and wears them in quicker. The object is to have the rings form their best seal before a > layer of varnish forms on the Cyl. walls, at which point, further ring seating effectively ceases. > For this reason, you should not go to high altitudes until break in is complete. With > steel or Cerminil Cyls., break in is usually complete within 1 Hr. as evidenced by a > stabilized oil consumption. Granted. But those of us with fixed-pitch props have to resort to higher rpm in order to pull more manifold pressure. I think we are getting hung up on semantics. The point I was making is the engine should not be flown gingerly, it needs to develop a lot of power (rpm or MP, whatever your particular engine/prop requires) in order to rapidly and reliably seat the rings. You guys with the CS props can load the engine at lower rpm, us folks with the cheap props have to wind up our engines (2400-2600 rpm) to get high MP unless we are flying at sea level. That's why a lot of us fly our new planes with new engines without the pants and fairings so breaking in the cylinders won't result in higher than desired airspeed. Sam Buchanan Darrell Reiley Round Rock, Texas RV 7A "Reiley Rocket" N622DR (reserved) --------------------------------- ________________________________ Message 31 ____________________________________ Time: 08:18:08 PM PST US From: "JOHN STARN" Subject: Re: RV-List: first flight --> RV-List message posted by: "JOHN STARN" Same engine/prop, same power....the -4 has a lot less frontal area.....if the -4 is not faster there is something wrong with the -4. I don't have drag numbers on either plane but I'll bet Kevin does. (would the F-104 be faster than a A-6 with the same HP/thrust ?? . A-6: 9,300X2, 18,600 thrust = 644 MPH, F-104: 17,500 thrust= Mach 2)) Drag-weight (frontal area ?) KABONG 8*) Do Not Archive > thing I have to disagree about is a -4 being much faster than my -6 at a > given power setting. > > Jerry > do not archive ________________________________ Message 32 ____________________________________ Time: 08:42:44 PM PST US From: Jerry Springer Subject: Re: RV-List: first flight --> RV-List message posted by: Jerry Springer I don't have drag numbers either I have actual experience. :) A couple of -4s I have flown along side of with matching engines and props I was actually faster than they were. Generally a -4 is about 3-4 mph faster than an equally equipped -6. Most of the -6s I am aware of have a hard time getting temps up in operating range. The -6 also has for all practical purposes a shorter wing span due to the wider fuselage, what that has to do with anything I don't know. :-) Jerry do not archive JOHN STARN wrote: >--> RV-List message posted by: "JOHN STARN" > >Same engine/prop, same power....the -4 has a lot less frontal area.....if >the -4 is not faster there is something wrong with the -4. I don't have drag >numbers on either plane but I'll bet Kevin does. (would the F-104 be faster >than a A-6 with the same HP/thrust ?? . A-6: 9,300X2, 18,600 thrust = 644 >MPH, F-104: 17,500 thrust= Mach 2)) Drag-weight (frontal area ?) KABONG >8*) Do Not Archive > > > >>thing I have to disagree about is a -4 being much faster than my -6 at a >>given power setting. >> >>Jerry >>do not archive >> >> > > > >