Cracked block or blown head gasket

1961 CHEVROLET TRUCK
1,000 MILES • V8
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GIVIE
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I have a restored 1956 Chevrolet truck with a small block, supposedly rebuilt. The motor began smoking out the rear side exhaust. I ran a compression test and all cylinders were 135-145 and the spark plugs all looked good. The truck ran good, didn't heat up nor any fluid leaks. Thinking it was possible a blown head gasket I removed the passenger side head a found a damaged head gasket and water in 1 and 7 cylinders. Since I had the motor tore down I decided to remove the driver side head and to my amazement I found water in #8 cylinder yet the gasket was in good shape.
Know I confused. How could water be in both sides. The intake and head bolts all seemed to be torqued down.
Any help would be greatly appreciated.
Jun 24, 2019 at 12:14 PM
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ASEMASTER6371
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Good afternoon,

If you had a leaking intake manifold gasket, that would explain the issue.

Did the intake gasket look damaged?

Roy
Jun 24, 2019 at 12:48 PM
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GIVIE
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The intake manifold gaskets did not look damaged, yet there is oil deposit inside each manifold channel that corresponds with the pistons that have water in them. Also one additional note, the manifold channel on each side of the intake manifold that is in the center, lines up with the carburetor, is full of oil. I previously checked the PVC valve and it rattled and assumed it was functioning.
Jun 24, 2019 at 3:44 PM
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ASEMASTER6371
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It could be rings for that issue.

A wet and dry compression test will verify that.

https://www.2carpros.com/articles/how-to-test-engine-compression

Was there any coolant in the oil?

Roy
Jun 24, 2019 at 3:46 PM
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GIVIE
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No water in the oil, and no oil in the radiator fluid.
Supposedly the engine was rebuilt, I know they all say that, but visually the
motor is beautiful. Also all piston cylinders do not have any edge at the top. The valley below the intake manifold is in perfect condition, no sludge or water deposits.
Jun 24, 2019 at 3:57 PM
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ASEMASTER6371
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I would have the heads checked to be sure they are not warped.

Roy
Jun 24, 2019 at 4:02 PM
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GIVIE
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I take them in tomorrow.
Why would oil be in the center channel on each side of the intake manifold which is below the carburetor?
Jun 24, 2019 at 4:13 PM
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ASEMASTER6371
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Rings, as I stated before. That's why you need to check the rings.

Roy
Jun 24, 2019 at 4:22 PM
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GIVIE
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Well, I ssume that means pulling the motor and dismanteling it. Is that correct?
Jun 24, 2019 at 4:29 PM
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ASEMASTER6371
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You are this far. You might as well pull it out and put it on an engine stand.

Roy
Jun 24, 2019 at 4:32 PM
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GIVIE
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Okay, thank you.
Jun 24, 2019 at 4:50 PM
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ASEMASTER6371
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You are welcome.

Always glad to help.

Roy
Jun 24, 2019 at 4:51 PM