Have a '72 455 in a jet boat, all liquid cooled right from the lake. Brother-in law owned the boat down in Florida, used it in salt water then let it sit for several years, bought it off him and brought it back to michigan but the motor was caked up with salt so I did a total rebuild. Ever since, it runs perfectly fine, does not burn too much oil, and never gains oil, but the dip stick is always milky and I have excessive crank case pressure to the point of "milk" blowing out the valve cover breathers and dip stick tube. Its not a head gasket, thought maybe it was water leaking past and overfilling to create pressure, been there, changed those. Pressurized both top and bottom end of motor and it lost 2 pounds over night, figured that was good enough. Could it be a ring gap tolerance? Any suggestions?

 

Interesting question. Milky usually means water in the oil soo......

But if you're not gaining and volume that points away from that.

Are you running a PCV system? Believe it or not that could cure it if it's being caused by over pressurization of the crank case.

 

i have tried that, running a PCV valve and hooking back into the air cleaner, seemed to make no difference except for a bigger mess in the air cleaner.

 

The PCV gets hooked to a constant vacuum source on either the intake manifold or the base plate of the carb, not to the air cleaner.

 

really? we've ALWAYS run them back to the air cleaner. Guess it cant hurt to try something new, guess thats the point to this forum.

 

I can get you a pic of the stock setup on my 70 442 if you'd like.

 

that would be very appreciated.