VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Help to locate1939 Master engine oil leaks

Are there any particular places that are prone to leaks on my 1939 216 ci engine? It seems to be dropping oil all over the place, but it's difficult to know where it actually originates from, that's why I need help to locate where the trouble might be starting. Is there a procedure I could follow to help me find the leak/s? Thanks.

Most common places are from the top down;
rocker arm cover
Side push rod cover
fuel pump lever pin.
timing gear cover seal
oil pan gasket
rear main bearing (no seal in a '39 and will drip from fly wheel cover
The rocker arm cover and push rod cover leaks can also cause oil to drip from the fly wheel cover

Start replacing gaskets from the top down

I have been chasing the same issue with my 41. I think it may be why the car has lasted so long, natural rust proofing / undercoating :)

Show me a stovebolt six that doesn't leak oil and I'll show you an engine that doesn't have any oil in it.

If gaskets are properly installed and rear main properly serviced there will be at most a little seepage.
At least that was the experiance with my 1934, 1939, 1950 and 1957....+....myCorvair.

I agree with Gene’s assessment. You can get things to the level of seepage. It takes attention to detail and patience. It took me 3 attempts to get the valve cover on mine to seal.

I have never seen a completely dry 216.

The easiest way I have found is to clean everything thoroughly and drive it and inspect after each drive. Seal the highest point that you see any oil dampness and then repeat the process but as others have suggested the only time those engines didnt dump a little oil is when there was none to dump.
Tony

Thanks everyone for the input, I'm not after bone dry, but various pools of oil all around just can't be right. I'll do as suggested, clean it all off and start at the top - and it sounds like I'm going to need quite a bit of patience to sort things out from other experiences noted here.

You may not find it 1st go, may take several attempts. Oil leaks are a pta to you and the person trying to seal them up.
Tony

If you clean the engine down, you will be able to see which area is causing the most leakage. Check the rear main crankshaft bearing as a first priority. If you find oil leaking there a common problem there is the drain back hole in the rear bottom bearing cap has become clogged with oil residue and carbon residue, and will not allow the oil to drain back into the sump. As stated there is no rear main crankshaft seal, so if the LD rain back hole is blocked ,oil runs straight out the back of the engine. There is a floating ball in the drain back hole of the rear lower bearing that prevents oil draining out of the engine back bearing when driving up hills. The ball must be free and clean to float backwards and forwards to accommodate oil draining back to the pan , and prevent oil lose going up hills.

Is that ball bearing only accessible when the engine and gearbox is split?

All you need to do is remove (drop) the oil pan and unbolt the rear main bearing cap. While possible, I believe adjusting the main bearing to have less clearance will help more and befoer I would do anything. Make sure the road draft tube is not plugged up with sludge. If it is plugged up, pressure will build up forcing oil out all over.

Thanks for the info, what do you mean by adjusting main bearing to have less clearance, how do I do that? Also unsure what/where road draft tube is, any further help and advice gratefully received.

When you remove the bearing cap there was originally some thin shims between the cap and block, to reduce the clearance you remove shims but removing too many shims will cause other major problems. I installed mine as a rebuild adjusting each main then loosening them off before attempting to adjust the next 1 but I havent tried adjusting in a fully assembled situation.
Tony

OK, I understand, thanks.