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View Full Version : Ls block can this be fixed?



toofun
07-26-2019, 06:48 PM
So a buddy of mine had an oopsie when handling his motor and this piece broke off the block. It is near where the starter would mount but broke off in one big piece( see picture) The part he is freaking out about is the last head bolt on the passenger side is exposed( see picture). Is this something that can be fixed or is the block compromised beyond repair due to the size of the piece that came off and more importantely that the head bolt is exposed.

If it can be repaired, how would a professional go about it and how do you ensure the integrity of the head bolt/torq? strength? this is also the part that has the transmission Dowel on it as well.

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andrewb70
07-27-2019, 06:40 AM
I am not an expert welder, but I fear the block is done. Hopefully someone else will chime in.

Andrew

dhutton
07-27-2019, 09:11 AM
Well I’m no welding guru but I think it can be welded. Pull the head bolt and run a tap through it after it’s welded. Might need the bellhousing to locate it correctly.

Is your friend trying to sell it or does he plan to use it? Probably not fair to sell it repaired like that imho....

Don

toofun
07-27-2019, 09:58 AM
No he wants to use it. If it can be used. I have heard of others welding these due to the starter breaking part of this piece off so I know it can be done. The only thing that worried me is the fact that the threads are showing on this break so question the integrity of that bolt. Just don’t want to have him weld it retap it then have it fail on him. Any experienced welders here that can chime in?

badazz81z28
07-27-2019, 12:10 PM
That’s a big piece! That is also the dowel locating pin for the bell housing. The engine is out...what is this ? LS1/LS2/LS3?

I would not weld it if it was my engine, but it surely can be welded being aluminum. It shouldn’t be too tough of a job.

toofun
07-27-2019, 12:31 PM
That’s a big piece! That is also the dowel locating pin for the bell housing. The engine is out...what is this ? LS1/LS2/LS3?

I would not weld it if it was my engine, but it surely can be welded being aluminum. It shouldn’t be too tough of a job.

Its an LS6 block, engine is out. Like I said more worried about the strength than anything else. It is where the starter bolts to as well as where the dowel pin is for the transmission and also the last bolt for the transmission. Pretty sure if it can be welded it would be strong enough for all of that. What he is worried about is the exposed threads on the head bolt. If that is not a concern for the strength of the head then he will find a good machine shop that will weld it back on. If that cannot be fixed due to the head bolt or other concern then he will have to go another route.

badazz81z28
07-27-2019, 01:22 PM
Its an LS6 block, engine is out. Like I said more worried about the strength than anything else. It is where the starter bolts to as well as where the dowel pin is for the transmission and also the last bolt for the transmission. Pretty sure if it can be welded it would be strong enough for all of that. What he is worried about is the exposed threads on the head bolt. If that is not a concern for the strength of the head then he will find a good machine shop that will weld it back on. If that cannot be fixed due to the head bolt or other concern then he will have to go another route.

Its hard to predict long term results....The head bolt will likely be fine. Its not going to pull out, but that area could create stress risers and cracks somewhere else. The weld is only going to penetrate so much and if too much, could that bolt find itself stuck in that hole? Don't know.

Bottom line is if he wants to pay and have it welded...Cool. I put my car on the track so I wouldn't chance needing to pull the engine back out and would use this opportunity to get a better engine. The LS6 isn't anything special.

toofun
08-10-2019, 03:43 AM
So I guess the bigger question is what do all of you think a fix like this would cost ballpark? 300? 800? 1000? More? Guess that will be the determining factor here.

WallaceMFG
08-11-2019, 10:43 AM
I don't see why it could not be welded back on. Remove the head bolt & head, weld up the bolt hole. Grind the broken piece so the weld can penetrate all the way in and weld the piece back on. Then the head bolt in question could be helicoiled to give it some more bite and spread the load to more material. A competent machine shop should be able to fix it. Luckily the bell housing ban be used to align everything.

What kind of use does this engine see? If it is just a street engine no sense in writing it off yet. Race engine, may have to think about it harder. Aluminum blocks are repaired from worse in the racing world, just a matter of cost.