A six cylinder engine has a 1 5 3 6 2 4 firing order. Technician A says that after cylinder number 1 begins its intake stroke, the crankshaft will have to travel 240° before cylinder number 3 begins its intake stroke. Technician B says that when cylinders number 3 and 4 are at TDC, cylinders number 5 and 2 are at BDC. Who is right?
A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question

Quizplus · Accepted Answer

In a six-cylinder engine with a firing order of 1 5 3 6 2 4, the crankshaft completes a 720° rotation to complete a cycle for all cylinders. Since there are six cylinders, each cylinder fires every 120° (720°/6). Therefore, after cylinder number 1 begins its intake stroke, the crankshaft will indeed have to travel 240° before cylinder number 3 begins its intake stroke (120° for cylinder 5's firing event, then another 120° to cylinder 3's firing event), making Technician A correct. Technician B's statement is incorrect because when cylinders 3 and 4 are at TDC, it does not necessarily mean that cylinders 5 and 2 are at BDC due to the engine's firing order and the positions of the pistons in their respective cycles.

A Six Cylinder Engine Has a 1 5 3 6