If two engines are rated at 20 hp and at the same rpm, it will produce the same torue at that rpm independent of the displacement or the compression ratio. Horsepower is horsepower.
An engine with a higher compression ratio will produce a given horsepower with less displacement than one with lower compression ratio. A large displacement low compression ratio engine can produce the same horsepower as small displacemnt high compression ratio engine. How ever if they are rated at the same horsepower and they have the same OUTPUT SHAFT RPM, THEY WILL PRODUCE THE SAME TORQUE.
Torque = HP/C X RPM!
These are facts. You can believe what you want.