Question $3$: Internal Combustion Engines$/$ Tractors and their Power Units

$3\mathrm{.}1.$Briefly explain the following $($support your explanations$/$discussion with sketches$)$:

$3\mathrm{.}1\mathrm{.}1.$ The operation of a four$-$stroke petrol engine.

$(10$ marks$)$

$3\mathrm{.}1\mathrm{.}2.$ The operation of a four$-$stroke diesel engine.

$(10$ marks$)$

$3\mathrm{.}1\mathrm{.}3.$ Discuss the differences between a two$-$stroke engine and a four$-$stroke engine

$(6$ marks$)$

$3\mathrm{.}2.$Given a $4-$stroke petrol engine with $6$ cylinders, with bore of $10$ cm $,$ stroke of piston of $15$ cm $.$ The mean effective pressure is $2000$ kPA and engine speed is $2000$ rpm $.$ Determine the engine theoretical power.

$(9$ marks$)$

$[35$ marks$]$