Question

When scavenging is done, some of the air and fuel mix with the exhaust gases and are expelled out of the cylinder before the exhaust port closes.

(a) True

(b) False

This question was posed to me in a national level competition.

My doubt stems from Hydrocarbon Emissions topic in chapter Engine Emissions and their Control of IC Engine

Answer 1

correct answer is:

(a) True

Scavenging in an internal combustion engine refers to the process of clearing exhaust gases from the cylinder and filling it with a fresh air-fuel mixture. In some cases, especially in two-stroke engines, some of the fresh air-fuel mix can escape through the exhaust port before the exhaust valve or port fully closes, resulting in the expulsion of unburned fuel and air. This can contribute to increased hydrocarbon emissions.