If compression is good and it runs and sounds good it should not be a problem and I would consider it normal for an engine that old with that many miles.

Try replacing the filter element in the can on the breather on the left front of the block.  If it's clogged the crankcase can't breathe as it should.

John - "The Hoosier Hurricane"

If the engine is all original, it does not have a PCV valve or system on it.  I would recommend getting rid of the OE draft tube and plumbing the engine for a more effective (cleaner) set up.  Do a search on this site as this subject has been discussed before and several solutions have been offered.  Bear in mind that this will not cure the basic cause for the vapor you see, i.e. blow by.  It will only mitigate the odor and staining you are now experiencing.

If your engine is indeed original it is 56 years old. The rings are probably worn allowing blowby. To stop the fumes fit a PCV system burn the fumes.

Regards


Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Have you cleaned your breather cap? If it's clogged it might be building up a little extra pressure forcing out more vapor. Just a theory.

Marc

'54 Merc ragtop

Pt Townsend, WA   

                                                                                                                                   

My stock original '56 272 seems to be breathing slightly more oil vapor from the breather cap than I expect. It's not remarkable except there is a bit of a smudge on the firewall behind it. Compression reads normal in all cylinders, manifold vacuum reads normal. The engine has 70K original miles, no rebuild (that I'm aware of.) and I can smell it a little especially shortly after I start up and get movin' down the road. I replaced the pushrod seals some time ago, with no effect.



Any suggestions?



Thanks in advance.



Granny '56