Assignment 4

CI ENGINE

SI ENGINE

SI ENGINE SPECS CI ENGINE SPECS

bore 86mm Bore 86mm

stroke 86.07mm stroke 86.07mm

connecting rod length 175mm connecting rod length 175mm

compression ratio 9.7 compression ratio 21

SI ENGINE PERFORMANCE CHART

CI ENGINE PERFORMANCE CHART

for the same stroke length,connecting rod length and bore si engine have more brake power although ci engine have fuel injection controller. ci engine got good brake effeciency and mininmum bsfc for same specs mentioned above.

BSFC : it is the amount of fule intake per unit brakepower output. keeping bsfc to minimum is very important criteria in engine design.

EXHAUST TEMPERATURE: it is the temperature of gases coming out after combustion . the temperature also depends on specific heats of gases coming out.

A/F RATIO: it is the ratio of mass of air to fuel. this ratio decides weather fuel is rich or lean.it decides the emission charecteristics of engine

3)

the above table shows engine performane after MFB is reduced to 50

from the results if mfb is reduced to halaf brake power is reduced to half.