Question: what are the 4 major parts of an elementary engine?
Answer: Cylinder. The engine cylinder is the part or space where fuel is admitted and reciprocating motion of the piston is obtained by burning it. ... 
Piston. ... 
Crankshaft. ... 
Connecting Rod. ... 
Cylinder Head. ... 
Camshaft. ... 
Valves. ... 
Rocker Arm.