300Tdi Engine
ENGINE
DESCRIPTION AND OPERATION
15
OPERATION
The 300 TDi is a 4 cylinder, water cooled,
turbocharged diesel engine with a capacity of 2.5
litres.
The cast iron cylinder block is integral with the
crankcase and incorporates direct bored cylinders.
The crankshaft is carried in 5 main bearings,
end-float being controlled by thrust washers which
are positioned on both sides of the centre main
bearing.
The flywheel/drive plate housing is an aluminium
alloy casting secured to the rear of the cylinder
block, it also forms the mounting for the starter
motor. A plugged aperture in the housing allows
access for the insertion of the timing pin.
The aluminium alloy cylinder head carries a
conventional rocker shaft and rockers, operating 2
valves per cylinder via camshaft followers and push
rods from a single camshaft, supported in the
cylinder block by 4 bearings and driven by a gear
and toothed belt from the crankshaft. A lobe formed
between the 2 inner bearing journals provides drive
for the fuel lift pump and another lobe, between the 2
drive end journals provides drive for the brake servo
pump. Camshaft end-float is controlled by a thrust
plate bolted to the cylinder block.
Graphite coated, aluminium alloy pistons are fitted
with 2 compression and an oil control ring and are
secured to the connecting rods by semi-floating
gudgeon pins which are an interference fit in the
small end bush. A swirl chamber is incorporated in
the piston crown to facilitate combustion.
The timing case consists of cast aluminium alloy
front and rear covers which house the oil pump,
crankshaft and camshaft front oil seals and which
also carry the fuel injection pump and drive belt idler
pulley. Housed within the timing case housing is the
crankshaft gear which provides drive for the
camshaft and fuel injection pump gears via a rubber
toothed belt.