@Gordon Nichols posted:"The other thing I noticed was how fast the head temp increases when the mixture is too lean. I richened it up and the temp came down IMMEDIATELY. I think our engines are fuel-cooled as much as aircooled"
Sounds just like an airplane!
With Subies if you modify the air intake, and you do not check your engine ECU program, you could lean out the mixture so much as to heat up the combustion chamber and blow the engine. Something that I learned from my subie tech who builds race cars.