ENGINE
DESCRIPTION AND OPERATION17
Lubrication
The engine lubrication system is of the wet sump
type, oil pressure being provided by the rotor type oil
pump (1) driven directly by the crankshaft.
Oil is drawn from the sump (2) through the strainer
(3), suction pipe (4) and passes through internal
drillings in the cylinder block to an external, full flow
filter (5). Further drillings feed oil to the cylinder
block main oil gallery (6) which, in turn, supplies the
crankshaft main bearings (7). Cross drillings in the
crankshaft carry oil to the connecting rod big-end
bearings (8). The camshaft bearings (9) are supplied
with oil from the main oil gallery.
An internal oilway from the camshaft front bearing
connects the cylinder block to the cylinder head and
feeds oil to the rocker shaft assembly (10),
lubricating the valves and springs.
The pistons, gudgeon pins and small end bushes
are lubricated and cooled by oil jets (11) which are
supplied from the main oil gallery via relief valves
which allow the oil to flow at a pre-determined
pressure.
Oil pressure is controlled by a pressure relief valve
(12) incorporated in the timing case housing
together with the oil pump. The valve allows excess
oil to be recirculated back into the oil feed gallery.
The rotor type oil pump is driven by 2 flats machined
on the front of the crankshaft.
Oil cooling is maintained by an oil cooler which is
integral with the radiator and linked to adaptors on
the oil filter head by pre-formed feed and return
hoses. A thermostatic valve in the filter head allows
oil to flow to the cooler when it reaches a
pre-determined temperature.
