Welding the manifold crack (Page 1/2)
handymanpat JUL 08, 11:31 AM
I have the typical cracked manifold and I have the engine out.
I do not think I can get the manifolds off without a lot of risk to breaking the bolts.
If the engine is disconnected from the computer and battery can the crack be welded while they are still bolted to the engine?
I think they can be but I figured I should ask before I do something really stupid.
Thanks Pat

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pat moody

Dennis LaGrua JUL 08, 01:45 PM
Sounds like you are talking about the notorious exhaust manifold in the back. An expert welder may be able to weld that on the engine but it would be extremely difficult welding all the way around the manifold. The part that sits next to the engine leaves very little room to work. I would remove them. The manifold bolts are difficult to remove so I would recommend applying penetrating oil daily and let it sit for several days. After that, applying heat, then tapping them and trying to remove those bolts should be possible.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

handymanpat JUL 08, 01:51 PM
Well, I was hoping for an easier solution.
I will keep soaking the bolts and carefully work on them.
The cracks do ot look to have made their way completely around to the backside so I was hoping to be able to weld the area I can see is cracked.
If the bolts won't come out and I have no choice other than to have them welded in it safe to weld them while on the engine?
It should not damage the engine should it?
Thanks Pat

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pat moody

Mickey_Moose JUL 08, 02:01 PM
Well, there is the risk of fire. I suspect that they would near impossible to do a good job of welding them on the car.

Since the engine it out of the car, you should just bit the bullet and remove them, you have already weakened them if you already tried turning them. Time for new bolts anyways.

Rodney Dickman sells a jig for drilling out broken ones that makes the job easy to do.
Spadesluck JUL 08, 02:01 PM
I would tack weld it while it is bolted down in a couple spots you can reach. Then when you remove it, you can weld it all the way around without the metal warping on you. This way it eliminates you needing a jig.
Dennis LaGrua JUL 08, 02:13 PM

quote
Originally posted by Spadesluck:

I would tack weld it while it is bolted down in a couple spots you can reach. Then when you remove it, you can weld it all the way around without the metal warping on you. This way it eliminates you needing a jig.



Excellent for maintaining alignment.
When you try to remove the bolts apply torque both ways but not too much, first to loosen then to tighten. In other words try to rock the bolts. Thats a technique I learned from an old timer mechanic. Look on You Tube for tips.

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" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

handymanpat JUL 08, 02:20 PM
Ok, I'm going for it.
I'm pulling them off.
Now here is the next question.
I ha e a set of non cracked non welded manifolds.
Would it be better to put on the replacement ones or the welded ones?
I would think the welded ones would be stronger?
Thanks for helping me to know to just get the old ones off.

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pat moody

handymanpat JUL 08, 02:25 PM
Ok, I'm going for it.
I'm pulling them off.
Now here is the next question.
I ha e a set of non cracked non welded manifolds.
Would it be better to put on the replacement ones or the welded ones?
I would think the welded ones would be stronger?
Thanks for helping me to know to just get the old ones off.

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pat moody

cartercarbaficionado JUL 08, 06:21 PM

quote
Originally posted by handymanpat:

Ok, I'm going for it.
I'm pulling them off.
Now here is the next question.
I ha e a set of non cracked non welded manifolds.
Would it be better to put on the replacement ones or the welded ones?
I would think the welded ones would be stronger?
Thanks for helping me to know to just get the old ones off.



mine are welded so make of that as you will. if you have some that aren't cracked I would have them weld a plate over the common crack areas to make them a little better
handymanpat JUL 08, 10:06 PM
I will weld up the cracked ones and use those, it makes sense that the welded ones would be stronger.
Thanks for everyone's advice.
Pat

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pat moody