Engine Lubrication: Description and Operation

SYSTEM FLOW
The engine lubricating system has forced-flow circulation, with the oil pressure being generated by a gear pump consisting of a pinion and an eccentric ring gear. The pump is driven by the crankshaft and is interposed between the timing cover and the crankshaft pulley. Oil is drawn from the sump to the oil pump (1) via an inlet strainer and pipe. A relief valve (2) in the timing cover limits the oil pressure and returns surplus oil to the inlet side of the pump. From the pump the oil flows through a passage in the block to the oil filter (3). The filtered oil flows to a thermostat in the oil pump adaptor. If the oil temperature is below 80°C (176°F) the thermostat delivers the oil to the main gallery. If the oil temperature is above 80°C (176°F), the thermostat opens and the oil circulates through the oil cooler (4) before being returned to the main gallery. The oil cooler is standard. The oil pressure switch (5), located in the main gallery, sends a signal to switch on the oil-pressure warning light on the instrument panel, to alert the driver if the pressure has fallen too low. The crankshaft main bearings and big-end bearings are supplied with oil from the main gallery and via passages in the crankshaft, whereas the pistons and cylinder walls are splash lubricated.








BEARING LUBRICATION
The front bearing (1) and the rear bearing (2) on the inlet-side balance shaft (3) are supplied with oil by the main gallery. The front bearing (4) on the exhaust-side balance shaft (6) is supplied with oil through a drilling from the No. 1 main bearing. The rear bearing (5) on the exhaust-side balance shaft (6) is supplied with oil through a drilling from the No. 3 main bearing. From the main gallery in the block, rising oil-ways to the cylinder head supply oil to the camshafts and cam followers. Via one of the cylinder head bolt holes, the oil flows to the camshaft bearings and cam followers through drilled passages in the head.