Oil from Vents

Something like these? :

"Joakim Soya" wrote

The rocker case vent contains a sort of metal sponge on mine, and it's also got a vent pipe to a valve and then to a pipe on the Carb flange. One tip, if you take off the rocker cover get a new cork gasket and use that red gunge to stick it to the cover only, do not stick it to the head, just a smear of oil. No oil leeks then.

Depends on the age of the engine. As originally built, the two vents had wire wool in them, oiled to act as air cleaners. The oil is renewed by oil mist from the engine, and these can be expected to emit small amounts of oil mist, especially if there is a fair bit of leakage past the rings. In later engines the one on the crankcase vent was replaced with a sealed cap and a hose added which led to a Positive Crankcase Ventilation Valve and thence to the intake manifold. A further hose led from the rocker cover vent to the intake hose elbow above the carburetter. (I think the change depended on the market, but probably about late sixties - but of course both the engine and the bits are interchangeable)

This later system should not emit any oil vapour, but with a lot of leakage past the rings allowing crankcase pressure to build up despite the PCVV, or if the latter is faulty, leaks may appear anywhere. The most common source of leaks is the rocker cover gasket and the seal below the rocker cover vent. JD

Thank You all for reply - It's a 69 Series engine - And the small domes are empty, i will add some kind of metal Sponge to catch oil mist.

Joakim "Joakim Soya" skrev i en meddelelse news:43ae74a7$0$47000$ snipped-for-privacy@dread15.news.tele.dk...

Don't know what I was thinking of with my reply but had a look at the SIIa and the metal sponge looks similar to the wire pan scourers you can get. More like metal straw than sponge or wire wool. One of those might do the job. Didn't feel like taking the mushroom apart to see how it came out though, despite the earlier bollock I dropped :)

All the best

I always thought they were flame traps.

Wayne - I'm not convinced that you did necessarily drop anything!

Joakim - how many liitle domes do you have? How big are they?

The rocker and crankcase breathers can drip oil if they are not washed out regularly. I'm trying to remember if it is easy (or even possible) to get the gauze out of these breathers.

Another leak point is the O-ring on the rocker cover breather.

I have 2 little domes - one on the Crankcase Vent Pipe and one on top of the rocker Cover Both are emitting oil (crankcase breather the most), and it is leaving the domes thru the Horisontal cutout's - where fumes are suposed to exit - so if someting insde the "little" domes are missing, a gadget that makes the Fumes go out the cutouts, but "catches the oil mist" and recirculates it. The diameter of the domes are 3-4 Inches, i will start a search for the O-Ring under the breather, when Snowing stops.

Regards Joakim

"Dougal" skrev i en meddelelse news:NqmdnWvK64hiRS snipped-for-privacy@eclipse.net.uk...