A friend of mine discovered milky oil in a 330. Engine sounds a little rough. I did a compression check and all is pretty good. Would a bad riser be the culprit?

absolutly,pull the plugs and crank it over with water hooked up,it will shoot out if the riser is bad or the head could be rotted out happened to me once.the steel heads are good for maybe 4 yrs in salt water.take riser off manifold carefully and look down center ,if traces of rust water drops or staining are present change them.

Good idea! I guess it will be a process of ellimination.

Intake gasket can go bad aswell.

I had this happen on a 330 before it ended up being a bad head gasket. Also what kind of temps is he running a very cold running motor will cause it also.

Johno, I had thought of that as well. That will be one of the last things to check prior to tear down. Hope the block is not cracked.

Carter, temps was about 180. I was going to have him pull the oil cooler and pressure test it as well.

Thanks for the input, Stan.

Ok, blocked of the hose's to the riser and bottom of exhaust manifold. Blocked the fresh water flush as well. Hooked up an adaptor to the supply line (old radiator neck) and pumped it pinning the needle. Very small decrease over time. The block is full of water and I marked the dipstick. I assume by tomorrow I will find out if it's the block.
If it was the oil cooler there would have been evidence of oil on the back of the transom through the exhaust.
Leaves me to believe the risers are bad. Also doing a compresion and leak down test as well.


Any other advice will be appreciated.


ps, would a bad riser cause the problem? How do you check the psi. Removing the was the ony way ai
could figure.
i

I replaced my intake gasket tonight on a HP500. I have used Felpro's & have had problems. Switched to Mr Gasket & this seems to fit the Merlin intake & water passage better. I was warned about the Felpro intake gasket, very thick material & not very wide around water passage.
Out & back in 2hrs HP 500 carb, done it so many times I can do it blind folded.
Leak down test will help, how many hours/years of age?

I had the same problem with my 330/454 TRS. The manifolds & risers were old and rusted. I swapped them out with new and no more water in the oil.

It took 4 oil changes to get all the milk out of the motor, however.

D. Ocean
Pompano Beach, FLA

He had the engines rebuilt several years back, apprx. 150 hours. I will do a leak down test today for him.
As far as the riser(s) being bad, I guess the the exhaust manifold(s) could be bad as well. Hope it's something simple for my sake.
thanks for the input, Stan.