Thread: Flat Head oil out of spark plug hole

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Recently purchased my first flat head powered 46 Ford. This car was driven 1400 miles in 10 years. Now that I own it I have logged more than that in 4 months.
After Sunday's drive I noticed oil leaking out around one of the spark plug holes.
My initial thought was possibly bad piston rings.
Are there any other obvious causes for this condition?
Bad valve stem seals or valve guides?

Have you pulled the plugs to inspect for oil on the ground strap, bottom of the shell and on the insulator. Ideally, the plugs should look something like cigar ash, with perhaps a little brown tint. They should be perfectly dry and not oily. If the plugs are oily, then look at the spark plug seats to see if some fuel and oil could be blown past the seats in the heads. Any dinging or damage to the seats will cause problems. Are they the proper spark plugs for the application?

wel this guy asked but hasn't been back---but on a flathead, there are two kinds of valve guides--early ones are split so they can fit around the valve stem because the valve tip is huge like a mushroon---the later ones are one piece but both kinds besides maybe letting oil up the valve stem can leak pass a defective rubber seal that fits arond the guide where it fits in the block--these old seals and new modern oils don't mix well and the intakes could be sucking up considerable oil and the valve will deflect it over toward the sparkplug area where it could get arond/thru the threads(partially stripped after 70 years) and leak out pass the 18mm copper gasket--------

flat heads do not use valve seals ? caddys do not .make sure the engine can breath

way to much oil

I usta' grind seats on flatheads @ an Engine Manufacturing plant, so I should maybe know this. It's been over 40 years ago though, so I have an excuse.

Not to hi-jack the thread, but the OP hasn't returned our calls anyway.

My curiosity got the best of me & I did a search for that place I posted about. I'm surprised it's still there. It was still a Ford Reman. plant back when I worked there. By the web site it looks like they've branched out a little. Not just engunz' Ann E. moore'.

Welcome to Universal Manufacturing

last one i did there was nothing there to grind . 16 new seats and now has bbc 1880 for intake valves and cut down inconels for EX

If the oil is around the base of the plug.. the plug gasket is leaking? ??? yes/no??
The oil shouldn't be coming up, it should (usually) be forced around interior parts.. yes/no??

Leaky spark plug copper ring. Don't most flatheads burn a little oil anyway? They didn't have CNC's back then....