Compare SI and CI engine on the basis of air-fuel ratio, power output, emission and knocking.

Compare SI and CI engine on the basis of air-fuel ratio, power output, emission and knocking.
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1 Answer

Answer :

Parameter
SI engine
CI engine
Air-fuel ratio
air-fuel ratio is 14.7:1
air-fuel ratio is 20:1 to 70:1 
Power output 
Power output is Less than CI engine due to lower compression ratio.
Power output is more than SI engine due to higher compression ratio. 
Emission
Emission is more.
Emission is less.
Knocking
Knocking take place at the end of combustion.
Knocking take place at beginning or start of the combustion. 
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