I think this is bad!

[BluLightning]

I finally finished taking apart my 460 and this is what I found in one of the cylinders. Almost looks like drill holes.


I know it's a crappy picture but what the heck caused that? I'm wondering if I should just start looking for a new block or have this one sleeved.

[cal67ss396]

Re: I think this is bad!

whooohahh.....how deep are those? I once had a BBC block that had pitting in the cylinders and they were able to bore it and get the pits out.

[Loren]

Re: I think this is bad!

Would need a better picture to say what caused it, but the loss of compression that cyl will experience when the rings ride over that will probably be insignificant. As long as there's no high spots! What's the bore at? Std, over? Perhaps .030 will clean it up if you wanted.

[BluLightning]

Re: I think this is bad!

I'm going to try and get a small depth mic to see how deep they are but I'm thinking boring is not going to do it.

[BluLightning]

Re: I think this is bad!

Would need a better picture to say what caused it, but the loss of compression that cyl will experience when the rings ride over that will probably be insignificant. As long as there's no high spots! What's the bore at? Std, over? Perhaps .030 will clean it up if you wanted.

I believe its a standard bore. You don't think it will lose compression going over holes like that? I bought the motor as a core so it's going to have to be bored anyway but I'm planning on building it to a 521 so I don't want to skimp and start off with a bad part.

[BluLightning]

Re: I think this is bad!

Actually a 514 is standard bore with a stroker crank and rods. Interesting. I saw those pits and I was upset. I thought the block was junk.

[BluLightning]

Re: I think this is bad!

Bigger is better but I don't want to build a crap block.

[milner351]

Re: I think this is bad!

I've never seen it in a gasoline engine - but that looks almost like cavitation of a wet liner diesel engine???

Strange that it would happen that close to the deck of the block.... hmmm

Yea - a sonic check would be a great tool to decide to bore it, or sleeve it, or get another block.

[joe_rocket45]

Re: I think this is bad!

I don't know how much Hp you're planning on but I wouldn't chance it, and i build crap too. That could be a bad casting and those pockets could start a crack...and they could be elsewhere, in the oil system or in the main webbing too.
At the very least check the block REAL good yourself, then take it somewhere reputable after that and have them give it the twice over.

[joebogey]

Re: I think this is bad!

If you're going to use it, I would say a full sonic check would be worth it, if that's not going to cost more than just another block. What if those are from the original manufacture and you have some on the jacket side of the cylinder wall where you can't see it.

[BluLightning]

Re: I think this is bad!

I'm leaning toward just picking up another block and not chancing it. I'm shooting for about 450hp and I certainly don't want a bad block to ruin my fun. ;D

[Caddyman]

Re: I think this is bad!

A good machinist might be able to "offset" the boring bar towards the spots a few .001's to cut a little more on that side (unless the spots incur more than 180* around the cylinder...then its a crapshoot).

But, if the spots are just the few shown in the shot, they aren't on a "load" side of the cylinder anyway...so it means less.

I'd check with a good machine shop before buying another..."its-going-to-have-to-be-bored-anyway"....block.

[cstmwgn]

Re: I think this is bad!

I'm leaning toward just picking up another block and not chancing it. I'm shooting for about 450hp and I certainly don't want a bad block to ruin my fun. ;D

Bob - you are going to have to leave out some parts if a 521 is only going to make 450hp - or did you mean at the rear wheels with a C6 :o

If you do decide to take the block to the machine shop to have it checked out, along with sonic checking the wall thickness also be sure to have them mag the rear water jackets ( at the very back of the block in the flex plate area) and the main webs just to be safe.

Personally, I would not run the block if those holes did not clean up with the bore. I would be concerned that the Molly faced top ring wouldn't like them all that much.

Good luck

[BluLightning]

Re: I think this is bad!

I'm pretty sure I'm just going to pick up another block. I'll see if I can find one from the early 70's.

[BluLightning]

Re: I think this is bad!

Good idea. I'd hate to be collecting boat anchors. ;D