Water In The Oil

[petew]

69 Super Cobra Jet ,belongs to a friend . It is a  fresh build from what I am told is a reputable shop.
I did a first start on it for him , ran it for about 25 minutes pulled a valve cover and found water mixed in the oil .
I have experienced this before and have generally found it to be an intake sealing issue.
Pulled the intake and found more goo in the lifter valley but the intake manifold gaskets appeared to be ok . The China rail corks were not used .
One intake gasket was a little suspect but not the smoking gun that I have found on other engines with a similar water issue.
No evidence of water in the combustion chambers, spark plugs are all uniform with combustion deposits and no evidence of being steam cleaned from water.
Where else should I be looking ?
This is an original engine that was in a car owned by my friends family since 1972 .
The only part ( other than rebuild items ) that not original is the intake.
The original cast iron intake was replaced by an aluminum PI .
That is why I went there first.

[blykins]

If the intake gaskets were not glued to both the head and the intake, then anything is possible. 

99.999% of the time, a water leak inside the engine is because someone messed up an intake install. 

Other remotely possible causes are:  1.  Crack/porosity in lifter bores/lifter valley  2. Condensation under the intake/valve covers are possible. 

[Porkchop]

My aftermarket aluminum intake leaked coolant into the valley. I had assumed it was because the fitment wasn't great so I had it machined to fit. Upon reinstallation, I noticed that the bolts I bought for the 6 inside holes were barely bottoming on the unthreaded shank of the bolt. It was hardly noticeable. Not sure if it was that way before the machining or only after.  There wasn't anything notable about the gaskets.

[GerryP]

You're too far down the rabbit hole now, but what you should done is a diagnostics before a teardown.  In this case, it would mean pressurizing the cooling system to see if it holds pressure.  Then a compression test to make sure the cylinders are doing good.  Brent has a lot of experience here and right now, you have to go with the intake gaskets as the culprit.  You could also be dealing with a casting issue.  You might be in the position of putting things back together and taking due diligence to make sure the intake isn't leaking (this time), then pressure testing to make sure it holds pressure.

[petew]

I think my part in this issue is done for now .
I didn’t build the engine and after taking a hard look at the intake I believe it to be the problem .I think the best course of action is for the engine to go back to the builder and let him sort it out.
If he refuses to stand behind it then I will reassemble the engine with another intake and go from there.
I am suspect of the current intake because it appears to have been Recently  machined on the port faces on both sides which I believe would narrow the intake ?
This intake is 60 years old and God knows what has been done to it and why .

[kcoffield]

....This intake is 60 years old and God knows what has been done to it and why.

If it had been previously used on a build that had either the block or heads decked, the intake would need to be cut to match those mods. Dimensional check, bot hole and pushrod clearance is pretty basic stuff during rebuild.

If your block or heads have been altered, a new lid may not fix it unless properly fit. If the mods to either the heads/block/intake were dimensionally minor, a thicker gasket choice may suffice......assuming it is fitment and not porosity of the water passages.

Best,
Kelly

[Phil Brown]

Had an aluminum PI intake a few years ago that had quite a bit of damage in the bottom water jacket area that needed welding to fix from sitting so long. One little pin hole can move a lot of water.
And as others have said bolt length, lengh of thread on the bolt, total length of the bolt, and the depth of the threaded hole