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MG MGB Technical - V8 Oil Leak

I have a racing 3.9 V8. There is quite a lot of oil on and around the pinion housing on the steering rack but I cannot detect where it is coming from. The steering rack is brand new. It may be coming from the sump gasket as crankcase pressure is a bit higher than I would like. I am trying to reduce this by fitting larger diameter breather pipes. It is most eveident after several fast laps but it is by then spread around quite a bit. Anyone have any ideas?
Richard Tinkler

Have a look at the rubber oil feed pipe to the gauge at the pump end found mine had rubbed through. It made it look as if the sump gasket had failed it is very near the pinion housing of the rack.
a goldup

How come there is any positive pressure in the crankcase at all? There should be negative pressure, from carb suction, as well the filtered fresh-air inlet to the crankcase. They are going to relieve any pressure long before you will blow it past a sump gasket, unless the sump gasket is knackered anyway. Could be from the front cover gasket, and there is nothing to say it *isn't* leaking past the rack oil seal and gaskets anyway. Clean the rack, wrap it in something, and see whether oil appears on the outside or the inside of the wrapping.
PaulH Solihull

As it's a race engine, I would assume that the crank breathers are venting into a catch tank, therefore no vacuum.
Dave O'Neill 2

But why so much pressure it might blow the sump gasket? No port to atmosphere to equalise pressures?
PaulH Solihull

This thread was discussed between 20/09/2010 and 24/09/2010

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