Here is a combustion engine i came up in the shower. It is an alternative to the piston and shaft engine and you have three seconds to explain why its retarded. Basically there is a shaft with a rocket like combustion chamber but it is linked to it such that it makes the shaft rotate. Kinda like if i attached a rocket to a carousel and used the resulting torque for useful work. Please tell me why this is worst than exploding gasoline inside a cylinder to push a linear piston that then has to transfer the motion again into circular motion. Its like three stages just to get useful work which is mostly the reason they are so inefficient.