Percentage of gain/per point of compression

[houser45]

Methanol engine. Sbc 11.0 to 1 compression with a flat top piston. Same engine with 12.0 to 1. Hp and torque gain of 2% ? Would it possibly be more?

[Walter R. Malik]

Methanol engine. Sbc 11.0 to 1 compression with a flat top piston. Same engine with 12.0 to 1. Hp and torque gain of 2% ? Would it possibly be more?

The lower the initial compression, the more the increase will be ... going from 11/1 to 12/1 I would imagine to be about 2 to 3 percent; If there is not a piston dome in the way of ignition.

[Alaskaracer]

As Walter said, piston dome will affect that, but also so will combustion chamber shape......piston dome impedes the flame front.....but poor combustion chamber shape affects it as well....then toss in camshaft and dynamic compression which is what the engine really sees.......it all starts piling up......