Question

The pumping loss is negligible in two-stroke cycle engines.

(a) True

(b) False

This question was addressed to me in final exam.

My question is taken from Total Engine Friction topic in portion Engine Friction and Lubrication of IC Engine

Answer 1

The correct answer is:

(b) pressure

In four-stroke cycle engines, pressure plays a significant role during the intake and exhaust processes. During intake, air (or air-fuel mixture) is drawn into the cylinder as the piston moves down, creating a vacuum. During exhaust, the piston moves up, and the exhaust gases are pushed out of the cylinder, creating pressure to expel the gases.