Need some c5 ls engine block welding information!
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Need some c5 ls engine block welding information!
A while back, my #1 cylinder filled full of coolant due to a defective head. The resulting hydro lock caused the starter to break off the block. The outside bolt hole threaded area cracked off the starter boss. I have the broken piece as it came off whole.
The engine runs fine after I drained the coolant out and pop started it.
My main question is, what aluminum alloy is an LS1/LS6 engine block???
I know someone that has a very good TIG Machine and is a good welder. I just want to have all the right stuff ready to go when the welding starts.
I also have to buy a TAP to chase the threads after all the welding is done. Got to figure out what metric size thread it is also.
If you have done anything like this or know how to and have any recommendation for a successful job "PLEASE" chime in and provide any thing that you can.
I sent the head back to the place that place where I purchased it and it was weld repaired. There was a pin hole in the floor (short side radius) which was welded up and the head was pressure checked SAT.
Thanks for any and all help that you can provide
Bill Curlee
The engine runs fine after I drained the coolant out and pop started it.
My main question is, what aluminum alloy is an LS1/LS6 engine block???
I know someone that has a very good TIG Machine and is a good welder. I just want to have all the right stuff ready to go when the welding starts.
I also have to buy a TAP to chase the threads after all the welding is done. Got to figure out what metric size thread it is also.
If you have done anything like this or know how to and have any recommendation for a successful job "PLEASE" chime in and provide any thing that you can.
I sent the head back to the place that place where I purchased it and it was weld repaired. There was a pin hole in the floor (short side radius) which was welded up and the head was pressure checked SAT.
Thanks for any and all help that you can provide
Bill Curlee
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
A while back, my #1 cylinder filled full of coolant due to a defective head. The resulting hydro lock caused the starter to break off the block. The outside bolt hole threaded area cracked off the starter boss. I have the broken piece as it came off whole.
The engine runs fine after I drained the coolant out and pop started it.
My main question is, what aluminum alloy is an LS1/LS6 engine block???
I know someone that has a very good TIG Machine and is a good welder. I just want to have all the right stuff ready to go when the welding starts.
I also have to buy a TAP to chase the threads after all the welding is done. Got to figure out what metric size thread it is also.
If you have done anything like this or know how to and have any recommendation for a successful job "PLEASE" chime in and provide any thing that you can.
I sent the head back to the place that place where I purchased it and it was weld repaired. There was a pin hole in the floor (short side radius) which was welded up and the head was pressure checked SAT.
Thanks for any and all help that you can provide
Bill Curlee
The engine runs fine after I drained the coolant out and pop started it.
My main question is, what aluminum alloy is an LS1/LS6 engine block???
I know someone that has a very good TIG Machine and is a good welder. I just want to have all the right stuff ready to go when the welding starts.
I also have to buy a TAP to chase the threads after all the welding is done. Got to figure out what metric size thread it is also.
If you have done anything like this or know how to and have any recommendation for a successful job "PLEASE" chime in and provide any thing that you can.
I sent the head back to the place that place where I purchased it and it was weld repaired. There was a pin hole in the floor (short side radius) which was welded up and the head was pressure checked SAT.
Thanks for any and all help that you can provide
Bill Curlee
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
If he's an experienced welder I would ask him what he prefers to use. I used 6043 rod with unmixed Argon and my heliarc when welding motorcycle cases. That was some nasty zinc filled crap.
Le Mans Master
Joined: Nov 2003
Posts: 8,004
Likes: 250
From: Tampa Fl
St. Jude Donor '12-'13-'14
Bill, When I did my heads and 2nd cam, My block was identified broking in the same area. I reviewed the records of my service when the car was new, and when the car was under six months old, the dealer replaced one head and the started. Though I have no evidence, I bet the dealership tech snapped the block when reinstalling the starter.
The good side is the car is 10 years old and always started ( well untill my third clutch), but its held on by the front bolt. The rear bolt is threaded, but does nothing.
One day it will break off, then Ill have to install a new motor because of the block
The good side is the car is 10 years old and always started ( well untill my third clutch), but its held on by the front bolt. The rear bolt is threaded, but does nothing.
One day it will break off, then Ill have to install a new motor because of the block
Pro
Joined: Feb 2009
Posts: 651
Likes: 33
From: North Port Florida
Bill, Sometimes when you have a hydrolock like in your situation, the connecting rod will bend slightly. You won't notice anything wrong till the rod breaks in half! Don't want to scare you, but I would check the deck height carefully on that hole. Good luck with the block repair!!
Tech Contributor
Joined: May 2008
Posts: 2,843
Likes: 16
From: Howell Michigan
St. Jude Donor '09-'10-'11
Bill,
The bolt is a M10 X 1.5 6g thread. The block is made of 319 alum alloy, filler should be 4145 or 4047, but up to the person doing the welding.
The bolt is a M10 X 1.5 6g thread. The block is made of 319 alum alloy, filler should be 4145 or 4047, but up to the person doing the welding.
Last edited by Eric D; Jun 10, 2010 at 03:49 PM.
Instructor
Joined: Jan 2009
Posts: 116
Likes: 0
From: Port Townsend WA
Hope that helps,
Don
Race Director
Joined: Dec 2004
Posts: 13,760
Likes: 75
From: Haymarket VA
Kevin
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
When I came into the house CURSING like a drunk Sailor and told my wife what happened, she immediately said. Now your going to want a stroker motor. 
Thats always an option but my little modded LS6 runs so good, I will keep it for a while.
After I reassembled the manifold and drained the cylinder, I "PULL STARTED" it with a strap and my Jeep and it cranked right up. I ran the **** out of it. I doubt if I hurt it. It only made 2 revolutions when I cranked it up before it locked up and popped the starter. If it grenades,,,thats another stroker opportunity to upgrade.
Thanks for all the cool welding info.
Keep the post going as I'm sure it ill help me and others in the future.Thanks
Bill Curlee
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Heres a picture of the carnage. The hacked up plastic cover happened getting the header out. 
This is what I saw when I removed the intake manifold. Both valves are closed so theres no coolant in the cylinder in this pic.
This is what I saw when I removed the intake manifold. Both valves are closed so theres no coolant in the cylinder in this pic.
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
WELL,,,,,,,,,,,,,,,,,,,,,,,,,,,They found the issue and they repaired it and pressure checked it. They said that it was suppose to be mailed THURSDAY last week. Have not seen a box on the door step as of yesterday.
I will let you know. I feel a LOT better that I found the real issue and no longer have a looming feeling that it will happen again. I was so afraid that I would have to reassemble it without being able to point to a smoking gun!
Bill
I will let you know. I feel a LOT better that I found the real issue and no longer have a looming feeling that it will happen again. I was so afraid that I would have to reassemble it without being able to point to a smoking gun!
Bill
Pro
Joined: May 2006
Posts: 723
Likes: 0
From: MOTOWN / Fort Dix NJ MI
Thread Starter
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Called Patriot today and here is what I was told:
I asked them if my head had been shipped back to me.
It wasn't!
The tech that was suppose to reassemble it and provide it to shipping didn't get the word to carry out that action. 
I was guaranteed that it will be shipped today.
BC
I asked them if my head had been shipped back to me.
It wasn't!
The tech that was suppose to reassemble it and provide it to shipping didn't get the word to carry out that action. I was guaranteed that it will be shipped today.
BC
Racer
Joined: Apr 2009
Posts: 359
Likes: 25
From: San Antonio TX
I did one a while back, but cant remember what alloy I used, just what we had for doing all of our aluminum cylinder head repair. As for the threads, as stated above, they are M10x1.5, and I would think putting a helicoil in there would be the best option since it may be pretty hard to get the threads lined back up perfect. If you're welder/machinist doesnt have the kit, I still have one from when I did mine.
And obviously make sure its cleaned good so you can get a good weld. We had laquer thinner and then used some other special aluminum cleaner and the weld turned out pretty decent, but the used block castings arent the easiest thing to get a clean weld on.
And obviously make sure its cleaned good so you can get a good weld. We had laquer thinner and then used some other special aluminum cleaner and the weld turned out pretty decent, but the used block castings arent the easiest thing to get a clean weld on.
Last edited by 67Ranger; Jun 12, 2010 at 09:48 PM.