hi there, i am studying the feasibility of compressed air to power a car as my final year project and i need some guidance. How i proceeded: (1) I derived equations for the driving force and consequently for the road-load power of a car, with speed as the variable. (2) I worked backwards using data about power losses in engine and in car transmission which i assumed to be almost constant. I tabulated the indicated power and indicated mean effective pressure inside the cylinder required at different speed (3) I then calculated the inlet pressures of compressed air required at different cut-off ratio and at different speed if the engine was to operate as a reciprocating piston air motor with 4 cyl in line such that when two pistons are doing the power stroke, the other two are performing the exhaust stroke. My questions are : 1.Can a conventional car engine be used as a reciprocating air motor, that is, with the same piston-cylinder assembly, piston rings, connecting rod, crankshaft? 2.What about the valves?