What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Operating RPM for RV-8 FP O-360

werxcv01

Well Known Member
I purchased a flying RV-8 with a fixed pitch Sensenich metal prop on a O-360 Lycoming. Redline RPM is 2700. What RPMs do most of you operate at for 1) flying around the local area and 2) cross country cruise at 7,000 MSL and higher? I usually use around 2350 for local fun flights and 2450 for higher altitude cruise.
 
RPM

Depending on weight and altitude, 2200 - 2300 gives 130 knots indicated which I use for lollygagging around.

Cross country I run 2550 to 2600 which gives 162 - 168 knots true at 9.2 gph or so.

With my current Ellison induction, full throttle cruise at 9000 to 11000 feet yields 2650 - 2750 RPM at 172 knots true burning about 10 gph.

I set the mixture based on altitude so above 9000 or so I can start going LOP but at high throttle openings with the Ellison it doesn't give good mixture distribution. Normally at peak or slightly ROP at high throttle openings. With the throttle lever retarded slightly LOP becomes more and more usable.

At altitude on a cross country I rarely run less than 2500 unless there's a big tailwind.
 
I got an IO-360 with FP.

X-country I cruise 2700rpm lean of peak and have done so for a couple hundred hours now. As soon as I am over 7000 feet density altitude I always cruise with full throttle and lean to 2700rpm lean of peak which is around 8-9gph depending on altitude. Runs very smooth at those RPM. Actually feels better to me then 2500... .

Performance will obviously depend a lot on what FP you have....

Local whatever ... .

Oliver
 
Thanks for the replies. I will experiment with higher RPMs at altitude. I have an EI 4 cylinder engine analyzer but with a carbureted engine I am hesitant to try LOP operation.
 
I have the smae set-up on my RV6A - O-360-A1A with a FP Sensenich. I run 2600RPM LOP @ 8.2 GPH. You can do that at any altitude. The engine is not as smoth at 2500rpm, and gets rough at 2700rpm - maily due to the throttle position not providing enough turbulance for the induction system.
I did replace my oil sump with a Superior sump to try to improve LOP fuel distribution, but I cant say it helped much.
 
Bill, I have the same set up as you on my -8, O-360, Senenich FP, one mag, LS EI.

2300 rpm locally and 2500-2600 x-country depending on the turbulence.

I run LOP most of the time except at full power. I am pleasantly surprised on how smooth and even all my CHT and EGT are at all rpm ranges for a carb'd engine.
 
Back
Top