Any way this isn't a crack?

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Cuda416

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My son and I pulled the head off his /6 last night in hopes of putting a new head on and rolling down the road. There is a jagged discoloration in #5 that looks like a crack. If you zoom in, there is also a scratch that I looks like it might be from a busted ring. Is a line like this potentially caused by a cracked ring?

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Link to updated pics showing the original "crack" is not, as well as an additional imperfection that also does not appear to be a crack based on the state of existing carbon in the chamber where there should be none had a crack been present.

Any way this isn't a crack?
 
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Looks like a crack ,I feel it was from a broken ring it would not be wave’y
 
You would think the crack would extend all the way up to the deck surface
 
Looks like a crack ,I feel it was from a broken ring it would not be wave’y

Yeah, that was my first thought when I saw it. A scratch would be straight up and down...

You would think the crack would extend all the way up to the deck surface

Had that thought too, but like Biff said, it's wavy...

This probably wasn't worth posting, I'm pretty sure the block is only good to keep a boat from floating away.
 
it's areal shame this one bit the dust as there is virtually NO ridge from ring wear at the tops of the cylinders....
 
A broken ring usually scores the cylinder in a straight line. This is not a broken ring. You need to clean up the area, even wire brush to inspect closer. It doesn't look good.
 
Thanks for the info everyone. I agree with a busted ring, there would be straights lines/sore marks. I'll try to clean the garbage out of it and look closer. Right now we're leaning towards rebuilding a 225 I have out back or dropping in a magnum. So far it seems like either way will cost about the same. If i could find a running /6 near us, that would be golden.

I never thought I'd say this but i don't relish giving my 16 year old something with any real power right off the bat. I was hoping to do was ease him into it, have him build more sweat equity etc. Anyway, thanks for the advice folks.
 
Take a razor blade and scrape away the carbon at the top. I think you will find it does go all the way up. I would bet money on that being a crack. Can you catch a fingernail on it?
 
Hard to see in that pic but there appears to be a faint line on the deck surface that looks like it extends from the pushrod well to the cylinder where the crack would be on the top of the cylinder. Either way it doesn't look promising.
 
Ok folks, this is weird. I scraped the carbon ring off and the "crack" came with it. it's like a "stain" of some sort. WTF? That said, there is a faint straight line visible now.

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Thanks for the info everyone. I agree with a busted ring, there would be straights lines/sore marks. I'll try to clean the garbage out of it and look closer. Right now we're leaning towards rebuilding a 225 I have out back or dropping in a magnum. So far it seems like either way will cost about the same. If i could find a running /6 near us, that would be golden.

I never thought I'd say this but i don't relish giving my 16 year old something with any real power right off the bat. I was hoping to do was ease him into it, have him build more sweat equity etc. Anyway, thanks for the advice folks.
I am totally with you on that. Years ago, I bought a wrecked original 74 360 dustpan. I initially wanted to fix it up for my 16yo son. But after fixing it up, i took one trip around the block, and I could see that would be a mistake.
 
That engine had been sitting for a while leading to that "run". That scrape on the wall is OK for and old engine. Cleanup the cylinders, oil them, put it back together and drive it. You and your son can find other things to work on.
 
That engine had been sitting for a while leading to that "run". That scrape on the wall is OK for and old engine. Cleanup the cylinders, oil them, put it back together and drive it. You and your son can find other things to work on.

That's the plan as of right now. This whole thing started with us needing a valve job. Going to go pick up the head tomorrow, gasket on the way home and slam it back together.

One thing though, three cylinders had pushrods that had jumped out from under the rockers. Seems a bit extreme but is that as simple as excessive lash? We haven't checked the lifters yet.

Any caveats based on that?
 
The pushrods being loose sounds to me like you had a couple of valves sticking.
In your last couple of pictures you can see there's a crack going up to the top of that deck on that cylinder.
 
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The pushrods being loose sounds to me like you had a couple of hours sticking.
In your last couple of pictures you can see there's a crack going up to the top of that deck on that cylinder.

Dang it, the "run" distracted me. Thanks for spotting that...


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It looks like a crack, but I don't see the evidence of it's being a crack. At least not into the water jacket. There should be rust in there. Is there water in the oilpan? And the top of the piston still has all the carbon on it. If she had run with water in the cylinder or steam actually, the top of the piston would show squeaky clean .
 
It looks like a crack, but I don't see the evidence of it's being a crack. At least not into the water jacket. There should be rust in there. Is there water in the oilpan?

Haven't pulled it yet. That said we drained the old oil didn't notice anything, but the guy we bought it from changed it fairly recently i think. The car did not run when we bought it, but we had it running for a few minutes once we got it home.

Seeing that, and the fact i have a lead on a motor that was pulled a couple of days ago that's supposed to be a runner, we're thinking of going that route.
 
Run that *****. . It's fine. Pick up the other motor for a spare but if you dig into either one, you're going to find something you're worried about. If you knew what REALLY went on in there, you'd be scared to start it.
 
Haven't pulled it yet. That said we drained the old oil didn't notice anything, but the guy we bought it from changed it fairly recently i think. The car did not run when we bought it, but we had it running for a few minutes once we got it home.

Seeing that, and the fact i have a lead on a motor that was pulled a couple of days ago that's supposed to be a runner, we're thinking of going that route.
Yours was also a runner.
Keep that in mind when buying a used engine.
 
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