Originally Posted by DanH
IIRC, Superior (specifically Bill Ross) is teaching the cause of guide sticking is not leaning properly, i.e. not operating in cruise with a high enough exhaust gas temperature. Many pilots do in fact shy away from the peak EGT region.
In retrospect, would you agree with Superior's position?
Another poster here. I have a Lycoming YIO-360-M1B (non-Thunderbolt) in my RV-8. I've had a sticking (not stuck) exhaust valve in Cylinder #2 happen twice, the first at 447 Tach Hours and then again at 1020 Tach Hours.
I purchased the RV-8 with about 210 Tach Hours on it. Since I've owned it I've leaned aggressively on the ground, use the Target EGT method for leaning in the climb, and run about 100°F ROP at 72% to 75% power, or 75°F to 100°F ROP at WOT and 2450 RPM at higher altitudes. I do run LOP sometimes, but not extensively. I normally don't run at peak EGT.
The first time the valve was sticking, we reamed all 4 exhaust valve guides, but only Cylinder #2 was crudded up, the other three were clean. The second time, we just reamed Cylinder #2.
My previous RV-8 had a Lycoming IO-360-A1A (PV) with 10:1 HC pistons (modified by LyCon). I ran it much richer in-flight (and never LOP) per LyCon's instructions, to make sure there was adequate detonation margins. In the 1900 hours I flew that airplane, the engine never had a sticky or stuck valve. I know the current owner and the engine now has about 2300 hours on it, with no difficulties.