Crankcase Ventilation

ENGINE - K SERIES KV6

DESCRIPTION AND OPERATION 12-3-17

Operation

Lubrication Circuit
The lubrication system is of the full-flow filtration, force fed type.

Oil is drawn, via a strainer and pick-up pipe in the sump, through the bearing ladder and into a crankshaft driven oil 
pump which has an integral pressure relief valve. The strainer in the pick-up pipe prevents any ingress of foreign 
particles from passing through to the inlet side of the oil pump and damaging the oil pump and restricting oil drillings. 
The oil pressure relief valve in the oil pump opens if the oil pressure becomes excessive and diverts oil back around 
the pump.

Pressurised oil is pumped through a full-flow cartridge type oil filter, mounted on the oil pump housing.  The lubrication 
system is designed so that a higher proportion of oil flow is directed to the cylinder block main oil gallery while a lower 
proportion of oil flow, (controlled by a restrictor in the oil filter housing), is directed to the engine oil cooler. The 
remainder of the oil flow from the outlet side of the oil filter is combined with the return flow from the oil cooler before 
being passed into the cylinder block main oil gallery.

The main oil gallery has drillings that direct the oil to the main bearings. Cross drillings in the crankshaft main bearings 
carry the oil to the connecting rod big-end bearings.

The oil pressure switch is located at the outlet side of the oil filter housing to sense the oil pressure level before the 
oil flow enters the main gallery in the engine block. A warning lamp in the instrument pack is illuminated if low oil 
pressure is detected.

Oil at reduced pressure is directed to each cylinder bank via two restrictors in the cylinder block/cylinder head locating 
dowels, one at the front on the LH bank and the other at the rear on the RH bank. Oil then passes through a drilling 
in the cylinder head to the camshaft carrier, where it is directed via separate galleries to the camshaft bearings and 
hydraulic tappet housings. Return oil from the cylinder head drains into the sump via the cylinder head bolt passages.

Crankcase Ventilation
A positive crankcase ventilation system is used to vent blow-by gas from the crankcase to the air intake system. The 
blow-by gas passes through a gauze oil separator in the camshaft cover, and then through hoses into the throttle 
housing and inlet manifold. 
 

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 EMISSION CONTROL - K SERIES KV6, DESCRIPTION AND OPERATION, Description.