RE: Cox Tee Dee 049 High Performance Cylinders
As I recall, with the original metalurgy of the piston and the cylinder, the hotter the engine got the tighter the fit became. Thus the taper was introduced to keep the bottom end friction down. My old speed engine I could drop a piston in from the top and it would drop through the cylinder when dry. How ever it takes a high RPM starter to start the engine. I think Bernie and his support group have the metalurgy better accounted for now.
George