ENGINE - V8 DESCRIPTION AND OPERATION 12-2-3 Crankcase The crankcase is made from Alusil for markets where the fuel contains a high sulphur content. The cylinder barrels have a nickel dispersion coating (Nikasil), and are finished by polishing only. An adaptor plate for the feed and return flexible pipes to the oil filter assembly is fitted to the left side of the crankcase. A water drain plug is located at the lower LH rear corner to drain coolant from the crankcase. Crankcase Ventilation The crankcase ventilation system is pressure regulated by a valve mounted at the rear of the inlet manifold. Vacuum supply ports are incorporated on the valve for the power brake booster and the fuel pressure regulator The pressure regulating vent valve varies the vacuum applied to the crankcase depending on engine load. The valve is balanced between spring pressure and the amount of manifold vacuum. At idle when the vacuum is high, the valve closes down and only allows a small amount of blow-by vapours to pass into the manifold. At part to full load conditions, the spring opens the valve and additional blow-by gasses flow into the manifold. An additional tube leads the blow-by gasses through the manifold and up to the mixing plate. The crankcase ventilation system is completely sealed. Hose clamps are used at all connections to ensure that the system does not contain any leaks. The crankcase ventilation system uses a cyclone separator to purge the blow-by gasses of any oil vapours. The oil vapours condense in the separator and drain back into the sump.