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oil pressure query - b series donk
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Author:  justincase42 [ Fri Jun 13, 2008 5:49 pm ]
Post subject:  oil pressure query - b series donk

Howdy, Just chasing a few ideas in relation to the oil pressure in my b-series donk. Motor is fully rebuilt, done approx 600km now and running like a trooper. The only problem is its leaking oil pretty bad out the rear end. The engine does not have a rear main oil seal but the spiral thingy on the crank that throws oil back into the engine.

My query is at idle the oil pressure sits at 50psi and at speed the oil pressure sits at 55psi. Irt doesnt matter if the engine is hot or cold, these values dont change. The Manuals suggest that at speed the engine should sit around 50-55 psi and and idle any where above 15 psi. I have put two breathers on the engine to minimise the crank case pressure but reakon the high oil pressure maybe causing some of the oil leak problems. Is it normal for the oil pressure to sit at 55 at high speed and 50 at idle, whether the engine is hot or cold? The manual suggests that the oil pressure releif valve opens at 50psi to re-leave oil pressure? Is there a possibility that the oil pressure valve isnt functioning correctly?

Im thinking of pulling the motor out and inspect the rear engine plate and check the gasket.

Any thoughts, suggestions, donations??
cheers
justin

Author:  Morris 1100 [ Fri Jun 13, 2008 6:23 pm ]
Post subject: 

Oil pressure is not related to crankcase pressure.
You can have very high oil pressure and negative crankcase pressure.

Is the oil leaking out in a stream, or just a mist or slow drip?

How did BMC fit the breathers to that engine originally?

Author:  justincase42 [ Fri Jun 13, 2008 6:58 pm ]
Post subject: 

I reakon the oil isslowly streaming out. It it blowing all over the gearbox, rear gearbox mounts and leaving a bad oil mess on the driveway. IT is using engine oil but gearbox oil is fine to eliminate a gearbox oil leak. Bmc had put the breather on top of the rocket cover and the pvc pipe to the air filter assembly. I have a zenith carby. I have added a side tappet cover with a breather pipe. THe 1500cc motors come with the side breather but the 1620cc motors didn't

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