I recently pulled my engine & tranny to do a rebuild due to a cracked head. Upon close inspection of the cylinder walls i found a slight groove in the #4 cylinder.

My Questions is..... Should i take the block to be bored or will honing correct this issue?

The engine turns smoothly and does not seem to be catching on anything.

If you intend to rebuild the engine, take the block to a reputable machine shop and let them inspect it and tell you what they can do. You will always be better off to get the opinion of a trustworthy professional, particularly if they have to stand behind the work.

I have rebuilt engines without taking them to a machine shop, and that has never worked for me. (Maybe I am just unlucky, but I doubt that...)

From what I can see in your photo it looks too deep to clean up with honing. Either way you need to do a full tear down. At that point you should do as Walter suggested and let a machine shop inspect the block and render an opinion.

Simple old school "shade tree" mechanic opinion;

Was it smoking or burning oil prior to the cracked head?

1)- If not, then it will not be a problem when you put it back together. The new rings will actually seal better than the old one did, so your position will not be any worse.

2)- If you had some smoke or oil consumption previously, then this area may have been the problem and you will may have some continued smoking or oil consumption after the rebuild due to this area.

Naturally, you are always "better" to have the engine vated bored and cleaned up. However, that will mean a FULL tear down and a little more cost for the machine work.

Edited November 21, 201113 yr by dltalfa

Isn't it likely that the scratches are from a broken ring or ring land? And how did the head crack? It might be warped also.

It sounds like you're either planning ahead or trying to decide how much the whole thing is going to cost you. A replacement head, or welding and machining on the one you have to fix the crack, plus a new piston or two, and rings, and other rebuild parts could get expensive.

Might be cheaper to find a used L28 without major problems and either rebuild it or just run it. They're out there. Just an alternative perspective.

Simple old school "shade tree" mechanic opinion;

Was it smoking or burning oil prior to the cracked head?

No, the engine was not smoking or burning oil prior to the crack.

Isn't it likely that the scratches are from a broken ring or ring land? And how did the head crack? It might be warped also.

It sounds like you're either planning ahead or trying to decide how much the whole thing is going to cost you. A replacement head, or welding and machining on the one you have to fix the crack, plus a new piston or two, and rings, and other rebuild parts could get expensive.

Might be cheaper to find a used L28 without major problems and either rebuild it or just run it. They're out there. Just an alternative perspective.

I will not know the full condition of the rings, etc...until i get it completely torn down. I'm still not sure how the head cracked....One day its running fine, and the next there was antifreeze in the oil pan. After pulling the head, i found the cracks coming from the #3 & #4 exhaust port. My guess is they were compression cracks from where the P.O. installed new valve seats himself.

Sounds like my best option is to go ahead and have a machinist take a look. If all else fails, i have an entire spare engine in the garage i can rebuild.

Thanks for the advice