Engine Operating Parameters

$1-$ Find : he diameter & stroke of a $4-$stroke $6-$cylinder internal combustion engine, which

develops $90kW$ brake power at a $3200rpm.$ The air to fuel ratio is $15$ and the calorific value

is $44Ni\frac{J}{k}..$ Assume that the the:mal indicated, mechanical and volumetric efficiencies are,

respectively, $35\%,90\%$ and $50\%.$ The ratio of stroke to bore is $1\mathrm{.}2$ and ambient air is at $1$

bar and $27C.$ Find also, the indicated specific fucl consumption.