LS6 Cracked Block Repair?

[SicMonte]

A buddy of mine is selling his warrentied LS6 motor but it has a small hairline crack on the drivers side by a freeze plug. I say it is warrentied b/c his old motor threw a rod and this new motor was installed. Once it was started up they discovered the oil leak while it was still on the lift. This motor is 100% new but the crack is freaking me out. The manufacturer sent him another LS6 and they never requested the old motor with the crack, so now he has a free LS6 just sitting around! He told me that he is going to have it drilled and welded before he sells it.

What is the "proper" way to go about fixing this problem. I want to do an LS swap and this is the best bang for the buck.

Any ideas/advice is appreciated!!

[ErikLS2]

If each end of the crack is drilled and the crack is V'd out a bit with a Dremmel and then properly
welded it should be fine. With something like this though, you never really know until you try it.
If it's at a substantial savings I would try it if it were me.

[67 ls1 vert]

Yes it can be welded. They heat the block up and weld it. It's done often. Iron blocks have been around a long time and this has been done many times. I say go for it. Get someone that knows what they are doing to weld it.

[SicMonte]

It's an aluminum block.

[TT302Z28]

There is not an issue here at all. As it was said above though, make sure that you take this is an expert in Aluminum welding. They will want to heat the block before welding then allow to slowly cool in an over after.

I machined an aluminum Donovan block years ago that grenaded in a sprint car. A shop in Sacramento took 6 hours and welded the block back together. Your situation doesn't sound nearly as drastic.

[Mike Norris]

I would be curious as to why it is leaking on a new engine.

If it is a crack, did it get dropped?? I would think there would have to be some kind of mark on the block as they do not just crack.

Or is it an actual casting issue and is pourous in that area?? If this is the case, then a simple weld up may or may not cure it and it could be weak in that area.

Not trying to wish bad luck on this as it has the potential to be a great deal, but these are questions I would be looking into if I were condering buying and using this block. Hopefully it ends up being an easy fix.

Mike Norris