ORIGINAL: Sport_Pilot
have to ask, in our glow engines isn't lubrication failure of the piston to cylinder seal a direct response to over heating?
No it is in direct response to a lean mixture which means less fuel, and thus also less oil. Run long enough and I suppose friction and lack of oil will cause overheating, especially in high reving racing engines. But the flame temp of low nitro fuel will not be hot enough on its own. A lean run on high nitro is another thing as the nitro can exceed the temp of gasoline, but much lower at max power.
ORIGINAL: Sport_Pilot
There is no problem with overheating on glow fuel, unless you are using high nitro fuel. The problem is lack of lubrication with lean fuel mixtures. If you convert them to gas they will operate at much higher temps without any problems, except perhaps a few with small fin areas.
There are perhaps a few exceptions to the above. For example a Fox Stunt .35 may overheat with a lean run with moderate nitro because of its very small fin area.
Now, I think we are all thoroughly confused?