Originally Posted by
TelsBoy
Rich/Lean of Peak refers to EGT.
Peak EGT is to the rich side of the best economy range IIRC - RPM wise I think that is when you set cruise power (e.g. 2200rpm), lean to peak RPM then keep leaning until RPM falls back to the original set value... however I could be wrong as I've never used that method in practice. ISTR that Best Power is lean to peak RPM then nudge it slightly rich, however my memory is somewhat hazy after several nights without sleep (teething toddler & pregnant wife about to pop No2 - not good
) - happy to be corrected where wrong.
(As said previously, all for NA fixed-pitch props)
Tels, been there, done that, have the tee-shirts re: children.
Peak EGT, is peak EGT. Period. The idea of setting '2200rpm' then leaning past max power (read more RPM) to (less power) the same RPM means you are at the same point in the power delivered arc in the Lycoming graph above. Nothing else.
You might or might not have gone past peak EGT, you might or might not be ROP. The method proves nothing and is just another OWT. By your own admission, you have heard about it but not tried it. Now you need not try it nor use it.
In a carbureted GA 'trainer' in cruise pull the red knob back till the engine runs rough, then richen only enough for smooth operation. If you have an EGT gauge then use it to set max EGT and leave it there provided it runs smooth. (Mr Lycoming's advice, not mine.) The reason for insisting on smooth running should be obvious, torsional vibration from uneven power pulses is bad.
Mr Lycoming says max power happens at 100 to 150F ROP, GAMI/Atkinson et al have found this figure is actually about 75 to 90F ROP so unless you have a fancy engine monitor, rather run 100 to 150 ROP if in a race.