Question

Blow by losses are reduced as the engine speed is ____________

(a) increased

(b) reduced

(c) unpredictable

(d) none of the mentioned

I had been asked this question during an interview.

My enquiry is from Engine Friction in section Engine Friction and Lubrication of IC Engine

Answer 1

The correct answer is:

(b) reduced

Blowby losses tend to be reduced as engine speed is reduced. At higher speeds, the pressure and temperature within the combustion chamber increase, which can cause more combustion gases to leak past the piston rings into the crankcase. At lower engine speeds, these losses are typically lower due to reduced pressure and combustion forces.