Cruise at wide open throttle above 8000 feet sounds like

alot of things are

wrong! Wait a minute maybe a fixed pitched prop could do

that. I'm not use to

that. One of the best advantages to using a rotary engine

would be a variable

pitch prop. Skip

Same for a constant speed prop! WOT 70% power at 8,000 feet roughly.
Manifold pressure down around 22 inches of Hg.
The RPM can be set on almost whatever.

The RPM will also be down I think for a fixed pitch prop
although I don't fly those very often.

Tracy, Ed, Finn, Chuck, Ken, Perry  what are you seeing at 8K WOT?

Paul Lamar

WOT at 8000' I get between 5350 and 5580 RPM, EGT's between 1480 and 1550

Chuck Dunlap

Am I reading you prop guys correctly, WOT RPM drops with altitude?
Looks like Chuck is leaning, which would cause some RPM drop.
My RPM seems to be the same regardless of altitude.  If I set the
throttle to a RPM, such as 5000 for example, it will be about 5000
at any altitude.  Of course manifold pressure and power are dropping
off as I go higher.  WOT is about 5400 RPM at any altitude 0-10,000 feet.
Next time I fly I'll get better numbers.
--
Perry Mick
Duckt N7XR
http://www.ductedfan.com

That is consistent with what Tracy says. The bite of the prop is dropping off
in the low density air so the RPM is not changing.

This chart shows that the blade angle must go up with altitude for cruise 
and maximum speed. Unfortunately is says nothing about RPM.

Paul Lamar
 
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