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crank case vent pipe

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Most likely bad piston rings - combustion gasses leak past, pressurize the sump and this forces air/oil mist up the vent pipe. Sorry for the bad news.
 
Agree, rocker needs re-build. Take valve cover off and run the engine. If you see more than a dribble from any rocker arm then you have found your problem.
 
I just replaced the rocker shaft on a BJ8. #9 rocker was so bad the oil squirted high enough to hit the open bonnet. Many times the shaft takes the wear and the bushings can be left alone.
Alan T
 
British Car Specialists on the West Coast and Healey Surgeons on the east coast can do this. You remove the shaft and pedestals and rocker arms and send them in. They replace the shaft and re-bush the pedestals and ream the rocker arms (I think--I had mine done 30 years ago, hard to remember the details, but it is a common Healey repair. You reinstall taking care to reassemble the oil banjo fitting carefully. A worn shaft will have deep grooves on the bottom of the shaft where the rocker arms pivot. Oil will shoot up in this case instead of dribbling out of the top of the rocker arms when the engine is running (idling).
 
If the rocker shaft is worn, then oil pressure might be down as low as 25 PSI at 70 MPH. 40 psi on a hot engine is about what BJ7s manage with the standard oil pump.

Crank case pressure from the breather is as Bill says, worn pistons and bores.

Ash
 
I second Bob's advice. Rocker Arm Specialist did mine too. Great job and fast. I don't believe British Car Specialist do the work but farm it out. Best to have the experts do it.
 
Do a compression test - this will help determining whether it's a worn rocker shaft or piston rings. Don't ignore the "both" answer.
 
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