Stupid engine rebuild

[TitanTn]

So I thought everything was fine. Wrong.

Started at the lake, ran like butter at the ramp. Drove about 5 minutes away and turned it off. Floated for about 5 minutes and tried to recrank. Turned over for a few seconds and then stopped. Couldn't get it to turn over anymore. Pulled the plugs and the cylinders are full of water. The oil is pristine. The water is in all cylinders, but mainly in the front two on each side. After clearing most of the water it never seemed to completely get it all, kinda like it was still entering however it's getting in.

Any ideas?

For those that haven't been following my story, the engine was rebuilt this winter. The block and heads have been fluxed. New guides and seats. Valve job. All new bottom end. New gaskets. 22 hours on the rebuild.

[supraaddict]

This might be a stupid question, but did you do anything different with the exhaust?

[ssa]

First thing I think I would check is the manifold to riser gaskets for leaks.

[TitanTn]

This might be a stupid question, but did you do anything different with the exhaust?

There are no dumb questions. Just a dumb boat that I'm sick of wrenching on. No, I didn't do anything different with the exhaust. The manifolds are somewhere around 6 years old I'm guessing. The previous owner bought them, so I don't know exactly.

First thing I think I would check is the manifold to riser gaskets for leaks.

I did a visual inspection when I had them off this winter and cleaned them out. They're not that old, and because this is happening to ALL cylinders I don't think I've had a failure on both manifolds at exactly the same time. I'm wondering if it's the intake in some way.

[michael hunter]

Check the intake manifold. Did you have the heads milled?

[TitanTn]

Check the intake manifold. Did you have the heads milled?

I'm walking down to the barn right now to pull the intake manifold. I'm not sure if damage will be visible to the eye or if I'll have to get it tested somehow. And yes, the heads were milled.

[cadunkle]

Odd for both manifolds or risers to fail at the same time, and I'd imagine given the angle of the engine it would be more likely to fill the cylinders towards the rear rather than the front. It's possible it could be intake leaking coolant passages to adjacent intake ports, though unlikely as it would likely leak into the valley and oil as well. Possible though. Did you RTV around the coolant passages on the intake gaskets? Even on hard to seal intakes with shaved heads I've never had coolant leak, though have had vacuum leaks.

I'd say head gaskets more likely. Try a compression test it may give some insight, though maybe not. I did head gaskets on a SBF a few weeks ago and compression numbers were good but couldn't explain an overheating problem so figured it was worth a look and had two cyls identical compression right next to each other. One cyl on the opposite bank has blown through to a coolant passage. Compression was good, plug and chamber looked normal, engine ran fine. Must have been minor, but it the gasket had failed. Just a thought. You could put air in the cylinders getting water and see if you can feel/hear air coming through the cooling system.

Still sounds more like cracked or rusted through manifolds and risers, or possibly failed manifold to riser gaskets, given water in all cyls. Another possibility is reversion. Since this is a fresh build what cam are you running? Too much overlap can pull water back into the dry part of manifold and into the cylinders at idle and low RPM unless you've got taller risers, water introduced farther back, etc...

22 hours on the engine, has it had any of these issues previously or just starting now with nothing changed?

[lively]

Intake manifold gaskets or head gaskets , you can verify this by doing a leak down at the t-stat housing and plugging the exhaust and circulating pump . But my guess would be the intake or head gasket . Don't get frustrated stay sharp and diagnose the issue


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[TitanTn]

Thanks guys. I'm just having a hard time thinking it's head gaskets or manifolds since it's both sides at the same time. If it was just one bank of cylinders I'd be checking manifolds and then head gasket. But this is both sides in equal amounts at the same time. Other than boring .30 over, everything is stock (cam, etc).

I've pulled the intake, and while nothing jumped out at me as the culprit, I'm taking it to a machine shop today for testing. I'm assuming they can test an intake somehow.

[chris young]

This is most definitely outside any personal expertise on my part, but I do remember reading something about the head gaskets on these motors being very easy to put on backwards. IIRC though the symptom was overheating on some cylinders, but it may be worth a look.

Sorry to hear about your issues, doing a rebuild should get you a better motor, not the other way round.

Good luck