"Denny" wrote in message
ps.com...
Confusion reigns, Dan... Lets assume a 2700 rpm continuous engine...
Extra fuel for cooling the exhaust valves comes when the throttle is
firewalled.... Pull it back a quarter inch and you lose the cooling...
Prop speed control comes from the setting of the prop governor
adjustment screw and/or the prop lever position... This also controls
the engines power...

So, if a 2700 rpm engine is adjusted to run 2700 at full throttle and
full prop lever then you climb at full throttle and full prop lever,
gaining the benefits of fuel cooling at max continuous power...
If the engine governer is set at 2750 and the pilot pulls the
throttle
back to reduce power to max continuous, then he loses the benefits of
extra fuel flow for valve cooling...

It's really got nothing to do with the RPM setting, per se, which
Robert's post implied. It's purely a matter of throttle and/or mixture
setting: one can run max rich at lower RPM.

--
Dan
C172RG at BFM