Boilermonkey Posted August 12, 2017 Report Posted August 12, 2017 The cowl flaps on our M20C don't close flush with the body of the airframe. They are not hitting anything, it actually looks like the linkages are adjusted intentionally for this. Is this common? Are they meant to close flush? Or are they intentionally left open a bit for airflow? Quote
carusoam Posted August 12, 2017 Report Posted August 12, 2017 It depends... Early in the C timeline cowl flaps were adjustable. At the end of the timeline, the flaps were set and not adjustable. With cowl closures, and other aerodynamic mods combined with the plane's personal OAT profile... Being set about an inch or two open seems to be the way... More attention to the health of the doghouse for cracks, holes and seals will probably result in better CHTs... To get a better idea of the future of the C timeline... look up David's cowling mod that has better air flow in its design... The old dog house came before the time when aerodynamics was applied to everything... From my hours as a C owner... not a mechanic. Best regards, -a- 1 Quote
orionflt Posted August 12, 2017 Report Posted August 12, 2017 They should be flush when closed and if I remember correctly 3/4 in open. I actually have Mike a bit more but I will look up the exact specs when I get home. Brian Quote
RLCarter Posted August 12, 2017 Report Posted August 12, 2017 (edited) Here ya go Edited August 12, 2017 by RLCarter Quote
Raptor05121 Posted August 12, 2017 Report Posted August 12, 2017 I'm curious why the M20C and M20D are different Quote
RLCarter Posted August 12, 2017 Report Posted August 12, 2017 1 minute ago, Raptor05121 said: I'm curious why the M20C and M20D are different They do seem to be all over the board Quote
Boilermonkey Posted August 12, 2017 Author Report Posted August 12, 2017 What about when it is retracted? Quote
RLCarter Posted August 12, 2017 Report Posted August 12, 2017 12 minutes ago, Boilermonkey said: What about when it is retracted? No spec for closed, only open 1 Quote
philipneeper Posted August 12, 2017 Report Posted August 12, 2017 7 hours ago, carusoam said: It depends... Early in the C timeline cowl flaps were adjustable. At the end of the timeline, the flaps were set and not adjustable. With cowl closures, and other aerodynamic mods combined with the plane's personal OAT profile... Being set about an inch or two open seems to be the way... More attention to the health of the doghouse for cracks, holes and seals will probably result in better CHTs... To get a better idea of the future of the C timeline... look up David's cowling mod that has better air flow in its design... The old dog house came before the time when aerodynamics was applied to everything... From my hours as a C owner... not a mechanic. Best regards, -a- Mine are fixed, non adjustable Quote
Boilermonkey Posted August 13, 2017 Author Report Posted August 13, 2017 6 minutes ago, RLCarter said: No spec for closed, only open Hmm the saga continues.... Quote
Raptor05121 Posted August 13, 2017 Report Posted August 13, 2017 1 hour ago, RLCarter said: No spec for closed, only open Interesting, only 2" when open? My cowls open to...a lot of inches. Way more than 2! Quote
Sabremech Posted August 13, 2017 Report Posted August 13, 2017 1 hour ago, daver328 said: Bob Kroemer (Mooney test pilot) in his classes the past two Mooney Summits has mentioned leaving them open about an inch and a half (1-1/2") during cruise ... Ever since I heard that - that's what I do! Ours ARE adjustable. I have mine adjusted as Bob Kroemer suggested. Quote
Raptor05121 Posted August 13, 2017 Report Posted August 13, 2017 I think I need to replace the cowl flap lever in mine and then rerig to these specs Quote
carusoam Posted August 13, 2017 Report Posted August 13, 2017 For the adjustable flaps... Also check how the cowl flap controls are connected to the engine mount. 1) My C's were connected with some hardware that was not very solid. 2) oil drops and dirt seemed to be part of the system. 3) some parts would slide when they were not supposed to. 4) some parts were stuck when they were supposed to slide. 5) I used Bob Kromer's advice and set them open and compared to a newer M20C with fixed flaps. I used Bob Kromer's written advice (often), printed in the MAPA magazine... 6) This all seemed OK, but there was no engine monitor to show how good this was working. Just a sole CHT and single EGT to work with. PP thoughts and old memories... Best regards, -a- Quote
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