351 Cleveland questions

Here's my question; I have a mild 351C it doesnt see many rev's above 3-3500rpm, it's a streetable enginew/mild cam.

What i'm getting is; it seems to blow a lot of oil out of the valve cover breathers, it has a PCV valve and everything is clean- no plugged hoses or lines, but this thing will oil my firewall and vave covers and makes a hell of a mess. It's a fresh motor w/ about 4k miles on it and it's getting old cleaning up after it. BTW the valve covers have baffles in them before and aft the vent holes.

This is a question all my ford buddies can't answer.

Could I get some ideas here, and no I'm not pulling it and putting in a Chevy!

 

broken ring or busted piston...time for a compression check

 

X2...although I'd suspect rings that never sealed correctly.

 

This is not a Ford question it is an engine question in general.
This engine has a broken piston / rings.
Do a compression test and find your dead hole.

 

Agreed! Do a comp check, you are showing blow by. I have been running a 351C for many years with no problem.

 

I will give it a comp check and see what's up. Thanks!!!!!!

 

How much compression, distributor advance and what do you run for fuel? Thing ever ping? Only time I blew oil thru the breather was when I broke a ring land because of ping, the soft spring in the dizzy was dropping and holding the mechanical advance open at times. Found the problem when the second know good engine started to ping and the only thing we reused from the old set-up was the distributor. BTW a compression check did not highlight this problem as the piece seemed to fall back into place when testing.

 

Are you running synthetic oil ? Can't break an engine in on synthetic.does it smoke out the back too?

 

The Dist is a Mallory unilite w/ vacuum advance. 8.5:1 compression. Never ran synthetic oil and it doesnt smoke.

My guess is the rings havent seated yet. My informants told me about ZDDP- zinc in the oil. This engine has a zinc additive in the oil, but maybe when it was in break-in period the oil was low on zinc, I dunno??

Did I mention the oil comes from both sides of the engine.

Thanks for the input guys..

 

The zinc wouldn't have any effect on ring seating... and many new cars use synthetiv oil as a factory fill these days.

 

I had a 351M and during the winter if the PVC became restrictive it almost immediately blow out the rear seal. Couldn't be something as simple as the PVC hose collapsing and then having the crankcase pressure and oil taking the easiest way out when back pedaling.