Water in oil after rebuild - looking for guidance

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I found my problem...

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I'm pretty disappointed, I'd like to know if it was something I did or it was like that when I assembled the engine after machining. I opted out of the magnaflux at the machine shop. This engine had 5000 miles on it before showing any signs of an internal coolant leak.
 
That is disappointing. I’m curious. Not saying this was the cause but did you retorque the heads? It’s a step many people opt out of because it means removing components and down time. It is a very important step.

Deciding to use replacement head bolts is another thing to think about because they do stretch. Had this happen but with a Chevy 350. I changed two sets of head gaskets before resolving that problem.

Both scenarios can cause leaks but I’m not sure about a crack. I would guess antifreeze is not the correct ratio or an overheating situation.

I would highly recommend in the future (if you haven’t) retorquing the heads for piece of mind. I recently installed new heads and the instructions do mention it.

Maybe get your torque wrench recalibrated too just to cover your bases.

Good luck
 
Looks like the gasket was leaking pretty good between #6-#8 cylinder,,,,look closely .
That’s a lot of pressure leakage for an engine with 5000 miles on it .

Tommy
 
Siksty7 Dart 270 said:
I'm pretty disappointed, I'd like to know if it was something I did or it was like that when I assembled the engine after machining. I opted out of the magnaflux at the machine shop. This engine had 5000 miles on it before showing any signs of an internal coolant leak.
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Did you chase the head bolt holes out with a tap before assembly? If there was dirt in the threads, that may have caused it.
 
Thanks for all the tips everyone. I did not retorque the heads. I did use new ARP head bolts and followed their instructions to a T. I didn't chase the bolt holes but I cleaned them with a bore brush and air and ran the bolts to snug by speed wrench to get a good feel for any trouble. The head gaskets were MRG1121G for a tad more compression. I came to find out they are poorly reviewed for sealing trouble on Summit. Maybe I can blame the gaskets but I can't be positive on that. If it was cracked there at the beginning, surely my machine shop would have noticed that when the deck was milled flat. I'm not confident in block sealant, there are two cracks each bridging the bolt hole to the adjacent water passages, I'd be worried that the bolt hole integrity is compromised.
 
Thinking out loud here. The crack goes from the water jacket to the bolt hole. Not the cylinder. At least from the picture.
How is coolant getting into the crankcase or cylinder? It would have to travel from a poor head gasket seal.
Looking at the gasket, are there signs of this leakage into the cylinder?
The head bolt hole should be a blind tapped hole so that can’t be the route to the crankcase.
I’m just wondering it some high tack spray sealant using a Felpro gasket would do the trick. I don’t know if you would create more of a problem grinding a groove and using JB Weld unless you are really skilled enough to file it flat.
At this point what do you have to lose except time and gaskets?
Chase the threads, retorque the head bolts and see what happens. You might just get lucky.
From the look of things the water had to mix because of that bolt not sealing the surrounding area. And or the cylinders in the area. A compression check would have confirmed that if you did one.
 
Question. Do those ARP head bolts use washers too? If so I used them too and it is recommended that you place lubricant on top of the washer for an accurate torque reading. Not under the washer but where the bolt rests on top of the washer.
 
I did do a compression check which checked out reasonably good. All cylinders except #7 at 135 psi (opposite side of the engine) were at 150 psi. I haven't pinpointed why #7 was down. There's nothing obvious on the gasket that says it leaked. I haven't pinpointed how the water got in the oil, I assume the crack extends low enough that it got in that way. The ARP bolts do use washers which were lubed at install. Cooling system pressure held 13 psi for 2 days after I tightened all the hose clamps chasing down those leaks, which tells me that it never achieved that pressure while running. Also never had any coolant in the catch can. Cranking the engine did not affect cooling system pressure.
 
If possible I would make a fitting to screw in the head bolt hole and attach an air line. If you have access to a welder or can drill out a 7/16? Bolt with a way to mate an air line you could do a leak down test or at least listen to the air escaping.
Just a thought.
 
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