Scott Gentile - CEO/Owner of A2A Simulations, he flies his Comanche with 18-1900 RPM and feed the throttle higher. it makes his engine run smoothly. Personally, as a sim pilot, I found that flying with "known power settings" makes the biggest difference to the enjoyment of flying and being ahead of the plane instead of behind it. At an indicated airspeed of 140 MPH. 2290 RPM. and MP of 19.5 I get straight and level flight putting the throttle down to 9.7 MP gives a descent of 500 feet. adjusting the throttle and knowing what "exactly" it will do has changed my mental capacity. But now I made it sound like I'm a flight instructor. I am not. 😊
Mike Bush has a video on leaning that covers the MP/RPM relationship. He says higher MP with a lower RPM allows for better prop efficiency with less frictional power loss, engine breaths better with better volumetric efficiency, runs quieter, and allows for an increase time for combustion to occur (as LOP slows combustion).
I too was going to suggest Mike watch some of Mike Busch's videos (YT: Savvy Aviation Channel). Mike B is a big believer in Low RPM, wide-open-throttle and Lean of Peak. The Low RPM & WOT allows for better combustion efficiency, and the LOP allows for better fuel efficiency and most importantly low CHT, which in turns extends the life of the engine, especially the exhaust valves. The tradeoff is slightly slower aircraft speed.
Of all the flying you’ve been doing, I thought maybe you would have been at the ICS convention in KC since it was so close to home……It was a great time…..8928P here :)
Thanks for sharing,looking forward to what you’re mechanic has to say. My guess is the prop taking a bigger bite and that is the slight vibration you are feeling. Mine does the same. Now try going lean of peak.....no chart for that, was not recommended in the 60s.
Hi Dan, I have dabbled with LOP very slightly in the past. I'm have a carburetor so cannot get a perfect GAMI Spread and have been reluctant to do it. I just figured out how to get 10 MPH back...and don't want to give it away. Maybe with $8.00 Avgas I will change my mind. :-)
I am a 250 carburetor also, my home airport is at 4600 ft. So most always full throttle,RPM like you do, clime to cruising altitude. When I go lean of pick CHT come way down ....burning 10 gallons a hour are less( RPM 2100). I do give up some air speed,some vibration, but works great with a tail wind!
You should land at my grass strip, about a two minute flight to 60IA, I can explain exactly why you picked up 10 knots. Great video as usual my friend.
I don't know if it warrants that but I would like to talk to one of the guys that have done all the aerodynamic tweaks to see if they get the same thing. One of the guys down in Missouri got is 180 going pretty quick by doing that.
Awesome video!! Question for ya usually a 3 bladed prop will cost a little in cruise speed. Does your published POH cruise speed/burn for a 2 bladed or corrected for a 3 bladed prop? Again great video! I’ve done the very same thing on my aircraft! 1967 Mooney M20E ( short body) IO360/200. I went with a 2 bladed scimitar prop instead of the 3 bladed. I’m like you, I get curious when numbers don’t align. 😃😃😃
Hi SierraBravo, No my POH does not reflect changes a different Prop makes. I have heard the same thing about a 3 blade providing a better climb but slower cruise. I also have to add in the extra drag from the Tip tanks. I guess the 10 MPH does not really bother me as I think the 3 blade simply looks cooler. lol :-)
@@pipercomanche2506 I 100% agree. Ramp presence with a 3 blades especially on the Comanche is 😎😎😎. Have a great day!! Again thanks for sharing the video
Like your videos! I generally need 50 more rpm than mp or it is a little rough. I also noticed in POH that running extended times between 2225 and 2275 is not recommended? I’m a 3 blade guy
@@raleighleesman1281 Morning Raleigh, I just looked in the limitations section of my POH and did not see that recommendation. Let me know when you find it and on what page. I am looking in the Killough manual for a 1958-1960 model serial number 24-103 through 24-2298 which is where my plane falls into.
Mike. I do not know where I read that? I retraced my steps and can only find limitations on running engine smoothly and avoiding high mp on a 180. I look forward to trying some different settings with more confidence if it ever warms up again. I do wonder about the the vibration and if it is a huge deal with a 3 blade prop? As I do not need additional aviation expenses:-) I’m based out of KPIR an old outfit there used Comanche’s for charter and said 24 square I know mine sure runs smooth at 2350-2400. You’re a Great American!
Looks right to me. Think this way, you dropped the RPM but you done that by decreasing the angle of the blades to the wind, and the prop now takes more bites of air per one rotation, less resistance, more efficient. The strange thing is the Gallons per hour, but you also added throttle. Can't tell exactly. Looks strange, but normal in the same way.
Lol, I have been flying 3-4 times since I made this video, I just have not recorded anything. It is a pain in the backside to edit everything taking me an entire afternoon to download videos. I would rather play Squad. :-) I have to goto Annual end of next month, I may record that.
