water in oil on new build

[Pedigry]

Brand new rebuild on small block ford 427. Rebuilt motor because I got water in the oil, figured it was a bad head gasket. Replaced everything but the heads, block, intake, etc. New gaskets throughout (cometic MLS). Decked block decked heads. Head bolts are blind so they don't go through to the oil pasages. Only thing I can think of is bad cylinder head gasket but it's brand new and the motor barely came off idle. I started the engine, let it warm up for 10 minutes or so, was burping the radiator, blipped the throttle a few times, motor sounded great, shut it down, went to check the oil and it was milkshake.

The heads were completely rebuilt when the motor was down. New springs, new valve seals, lapped the valves, did a water test on all the combustion chambers, no leaks. I figured if there was a crack in the heads I would have seen it.

The block was line honed, decked and bored. It's an aftermaket World products man-o-war block. It's really heavy duty. I highly doubt there is a crack in it but I am running out of ideas.

Head gasket is the most likely culprit but it's brand new and the motor never came off idle and only ran for 10 minutes.

I'm stumped. The reason I rebuilt the motor in the first place was because of milkshake oil. Now I have completely rebuild and replaced virtually everything on the engine and I still have the same problem.

Pretty dissapointed as this has been a pretty big job. Outside of pulling the engine again and tearing it apart I'm not sure what else to do.

My only thought was to drain the oil, change the oil and the filter and retorque the heads. I know they are torqued because I inked every head bolt after torquing them but it's the only thing I can think of.

Any suggestions are appreciated.

[Olds.PhD]

Intake gasket not sealing the water jackets?

[Pedigry]

Yeah maybe. I’m getting white smoke. I’ll pull the I take manifold tomorrow and see what I can find.

[Vimes]

That sucks. You can do a radiator pressure test to see if you have a bad head gasket. A parts store should have one to rent. Pull the spark plugs and make sure the rad is topped up, then pump it up to 15PSI. If the head gasket is bad water should come out of the bad cylinder(s). Drain the oil as well, and put a catch can under it. If water comes out of the oil sump but none comes out the spark plug holes it'll be a crack in the block. Hopefully it's something simple.

[Pedigry]

217588217588

Guess which cylinders have a coolant leak…

[Vimes]

Bummer. Same cylinder on both banks sounds like the head gaskets might be flipped front to back. Annoying, labor intensive with the engine in the car, but relatively cheap to fix vs a cracked block.

I'm not a Ford guy though, so don't take my guess for it.

[Pedigry]

IDK. The gaskets were correct front to front. I put copper coating on them as per my engine builder suggestion. They do 100 engines a year and swear by it so that's what I used. I am thinking maybe not use it this next time. Though it's hard to believe it would cause an immediate leakage.

The only thing I can do is put it back together with new intake and head gaskets and try it again. Parts are coming in Wednesday so by thursday or friday I should have an update. I wish I could find a smoking gun, I would feel alot better. If it does it again I am thinking I may have to dissaemble the whole motor again and get it magnafluxed to see if there is a small hidden crack somewhere that I can't see.

The offending cylinders were 7 and 8. They are right next to each other on a ford. So the two rear cylinders on the same side.

[79 Camaro]

Back in the day and I mean way back (40 years ago) I was a line tech at a Chev dealership. The method we used for finding a leaking head gasket was as follows.
Fill the radiator as needed. Warm up the car to operating temp. Take the rad cap off carefully. Install the pressure tester on the rad. Pump it up to 15 plus psi? And then let it sit over night. The next morning pull the plugs and see which ones are wet if any.
Total guess on my part is are the heads decked so the intake manifold angle and the head angle don't match?

[Pedigry]

Welp, mystery solved. Unbenounced to me, the world products blocks take their own special head gasket. I ordered a 351W head gasket for a ford block assuming it would be correct. I was wrong the WP man-o-war blocks have a special gasket. The truth is, the 351W gasket that I put on it lined up with all the water and oil passages so I'm still surprised it leaked, but at this point, I'm just happy it's not a block or head crack. Should have it back together by the weekend with an update.