Question

In CI engines fuel is injected into the combustion chamber at about 15ºC ___________ TDC during compression stroke.

(a) after

(b) before

(c) at

(d) none of the mentioned

I got this question in an online interview.

Asked question is from Combustion in C.I. Engine topic in chapter Combustion and Combustion Chambers of IC Engine

Answer 1

The correct answer is:

(b) delay period

The delay period typically extends for about 13° of crank movement, during which the fuel injection occurs, and the ignition process starts, but the pressure has not yet significantly risen. This period is critical for the proper combustion initiation in the engine.