How to, and why to:

This article has been reproduced by kind permission of Norman Nock, British Car Specialists in California. The original is contained in his excellent book, Tech Talk.

Austin Healey Oil Leaks
by Norman Nock

Does your Austin Healey leak oil from the rear crankshaft into the clutch housing?

To use this modification, your engine has to be in good mechanical condition and the rocker arms must not be worn, Remove the the rocker cover and inspect for excessive oil flow to the rocker arms. Run the engine at 3,000rpm for the inspection. If oil flow is high, or you have a gusher, or your fenders are now splattered with oil, do not introduce this modification to your engine.

6 Cylinder Engine Only
1. Remove the hose from the air filter to valve cover.
2. Remove tapered plug from rear of inlet manifold.
3. Insert an appropriate fitting into the manifold.
4. Remove oil filler cap and close up the small breather hole with solder.

The Type 1 metering valve is obtainable from most auto parts stores.The device conducts crankcase blow-by gases to the intake manifold through a variable orifice valve, the opening of which is controlled by intake manifold vacuum. The valve is designed to have a scheduled flow rate to handle blow-by gases.

When the engine is idling and manifold vacuum is high, the valve is closed. A small orifice handles the flow.
At manifold vacuum of 12 to 15 inches of mercury, the valve begins to open allowing the increased blow-by of the engine to flow through as the manifold vacuum decreases.
With the removal of the positive crankcase pressure to a negative pressure, the oil will not be forced out of the rear crankshaft seal.
AUSTIN HEALEY TECH TALK l have been writing technical articles for the Healey clubs for over 20 years. After numerous requests l have gathered them together along with some never before published articles and had them spiral bound in book form. Available from British Car Specialists. Norman Nock.

I had fitted a Denis Welch crankshaft oil seal to the back of my BJ8 some time ago but still experienced the customary slight leak. It was better, but not cured. During my RHD conversion, and with the engine out of the car, I re-fitted the device, using a new seal. I felt at that stage perhaps I hadn't done a very good job the first time. Well, it is a pain fitting the seal from inside the cockpit with the only the gearbox out. Unfortunately the weep persisted.

Having read Norman's article in his excellent 'Tech Talk' book, I felt it had to be done, so I bought a kit from his company. A fax confirmation with my credit card details supplied a complete kit of parts. The PCV costs just $10 but shipping increased that by a further $20. The exchange rate is good for us in the UK so it wasn't too painful.

Fitting was simple enough. It took less than an hour. The breather hole in the flip-up filler cap was filled with Araldite to maintain the vacuum. I use K&N air filters and that resulted in the original breather venting to atmosphere by dropping a longer breather tube into the inner wing area. Connecting the breather to the manifold tidies up the arrangement nicely.

The negative pressure created in the engine absolutely eliminated the slight weep from the rear bearing. It also resolved a problem with a slight dribble on the rocker cover from the filler cap seal whenever I gave the car a high-speed run.

Highly recommended.

Alan Bromfield
(We're just the current and temporary custodians .................)