Originally Posted by
Charley
Why not? I ran 15% nitro in several Italian STs in the 1980's when I lived in El Paso, TX, @4500' MSL. I took two of them to Houston for an AMA fly-in. Guys there told me 15% would overheat my engines in the high humidity and sea level pressures. I said uh-huh and continued to fly my models all weekend.
CR
My experience is that the older ST's ran best with a lot of nitro, up to 20% anyway. The old crossflow engines had about the same compression as the US made versions. It was not till the 80's, probably the late 80's that US imported engines had higher compression ratio's.