beam engine bourke engine britalus rotary engine cam connecting rod controlled combustion engine crankshaft cylinder head porting flat engine free-piston engine gas turbine h engine heat engine jet engine lubrication mechanical engineering multi-valve napier deltic one-stroke cycle opposed piston engine orbital engine peaucellier-lipkin linkage piston piston valve piston valves pistonless rotary engine poppet valve quasiturbine radial engine rectilinear rocket engine rocket engine nozzle rotary engine single cylinder engine six stroke engine sleeve valve steam engine steam locomotive stelzer engine stirling engine straight engine superheater swing-piston engine thermodynamic cycle twingle engine v engine valve valve gear w engine wankel engine william murdoch