[Ol' Ron]

I use Egge Pistons in most of my builds and never had a problem with them. Defamation, is usually caused by excessive ignition timing. However a low oct. ifuel, in a hi compression can cause this as well. It hard to get that much compression in a flathead. The spark plug doesn't enter the picture here, the worst thing would be if it hit the ex valve. I don't like using Ross pistons in a street engine, due to the excessive piston clearance. This can lead to pil commission in a low time engine. A street engine needs a tight piston.