welding a freeze crack

I now have a 4 inch freeze crack in my S/B 350 about an inch down from the deck , what type of a welder and what would be the correct way to weld it not to make the crack travel ? any help would be great.

 

If it is not a unique or special block, you might just want to replace it.

Otherwise you will want to weld it with a stick welder and high nickel rod (your welding supplier will know the one), after properly prepping the crack.

Drill a hole that is about 3x the width of the crack at the ends, to stop the crack from spreading. V-groove the crack. Heat the area with an oxy rig until it is just about at welding temperature. Then weld it. After welding, keep heating the welded area heated with the torch, slowly withdrawing the heat from the welded area. Once the torch is away, take whatever steps you can, insulation, etc. to keep the heat in, and to allow the weld to cool as slowly as possible.

Others will weigh-in with whatever I missed, and with other methods.

 

I have a Nailhead block that needs this love also

 

350's still grow on tress.

 

You can use a piece of cast, like a broken chunk of cast, preferably from another bad block or something and TIG it( I have heard of this only and have not seen it done but it makes sense) Or nickel rod and TIG (personally done this with success but not on a block repair)

 

This is how I was taught

 

Seems like too much work for a block that you can pickup anyplace - for really cheap.

Also, in some cases the uneven heating/cooling can distort the block, bores, deck. Places that do this professionally have temperature controlled ovens to bring the heat of the whole block up at a consistent rate, then weld it . . . then cool it at a consistent rate. All of this is to ensure the integrity of the weld and to minimize distortion. Even after this, in some cases machined surfaces need to be touched up.

 

The 350s might but a 425 Nailhead out of a 65 Rivi GS don't. When I found the crack it was like getting kicked in the sack

 

I had a 3 inch crack in one of my 428 blocks. I used the " iron-tite"
method and it provided a permanant repair. It is done by
installing tapered iron plugs. The first two installed at the ends
to "capture the crack". Then continue with overlapping plugs
to replace the crack with cast iron repair. The last step is to
peen-over the cast plugs to seal-it. I ran pure water for a short
period of time to allow the plugs to rust-in and seal. I have a
a fully repaired block. Been running it for about 2 years without any
trouble. I was weary of welding close to the lifter bores (see pic)

 

Piece of mind........Replace the block.

 

I agree. For a $50 wrecking yard 350 I'd just replace it.

 

Why not just solder it up with bronz or lead if all it has to do is keep the fluids inside then that will be the easiest and safest method to not cause more problems. If its actually a hole you can solder the old piece back in or just use a piece of sheetmetal its a big stong block already there is no need for fancy welding to just keep the fluids inside.

Paul

 

NiRod is probably the best, however where exactly is the crack? Material thickness? PreHeating to the appropriate temp (Depending on thickness), welding it, then Wrapping the block with R32 insulation (primarily the affected area) to slow cool the weld is key. If the parent metal surrounding the weld cools before the weld or v.s., it will seperate...crack. Good Luck.

MONDO

 

i did one wrong once and chased cracks all over the place
i proabbly would try JB weld
hit water on a SBC head and JBed it and it held until some lame kid tried to get the temp to 350 degrees or something and melted it out, worked good until that

 

I just talked with an engine shop owner about threaded deals. He said the threads are "reversed" and the plug pulls the cracked area together. I guess he means the widest part of the thread is at the outside, and the "pointed" part of the thread is inwards?

He said the plugs are tapered and the head breaks off at a certain torque. Then they grind and hit it with a needle scaler to mimic a cast look.

 

I have a pretty simple method and have real good luck with it on most cast. I buy the cheapo stick cast rod, not the nickel. I don't preheat or post heat either. Of course drill a small hole at each end of the crack. Weld a short bead, maybe 1/2 inch long. then peen the shit out of it with the pointy end of your chipping hammer until you can almost touch the weld without getting burned, repeat until finished. Make sure they are good welds with no undercut. It also helps to grind the weld and even use a flap wheel to smooth it out after you're done welding.

 

Nirod 59 You have too preheat the shit out of your part at least 400.then get a jitterbug and peen the shit out of it ALOT.dont forget to drill each end of the crack.Then wrap the fucker good and slow cool it.If your block is shitty mat. nuthin will work.I helped on a block with alot of nickle.still real iffy.

 

I brought up irontites once before Mike, and no-one seemed interested. Its too bad, because they work. What you are saying about overlapping is actually called " laceing ". Done properly, they are a excellent and very effective repair, even under racing conditions, and ruthless dyno testing. They hold up in Deisels for hundreds of thousands of miles. And yes HE is. BDM

 

That's right, the kit has a tapered reem, tap and corrected drill bit.
The plugs are made of cast, so they expand and contract with the
block with heat cycles.....
I did my repair by only removing the intake. No extreme tear-down.

 

Thanks guys for all the info and I called our local Engine Connection and they gave me a price of 690 bucks (bare Block + mains)for another Block prep to what mine is now. so in the meantime I Goggle and found Muggy welding.com and I think it might be worth a try using one of there kits for a 100 bucks. oh buy the way the motor I am talking about is in the dragster on the left in the picture. profile picture. I havnt got that much money in this motor 3 or 4 grand. so I pull it put and put my blown motor in the car yesterday.
Thanks again guys
Bud

 

Ok then, tip it on its back, fill the block with block cement, and just run water in the heads.

 

My first thought was to replace the block (I would want the piece of mind) ... now that I know it is going in a dragster I agree with just filling the block (with cement or Hardblock), although I would suggest drilling holes at each end of the crack to prevent it from spreading.

 

Here is a link to Muggy Welding. After reading this they say there is no need to do the heating and cooling ritual if you use the right rod.

http://www.muggyweld.com/castiron.html

Looks like this is the way I will be going

 

ya I use to do that. but now day they jack you around at the track for tow vehicles so bad I usually over heat or run out of fuel before I can get back to the pits it takes about 5 gal alka in a run and I only carry 6 gal total.

 

BinderRod
ya it looks like it might work ok and the video is pretty good too.
But in the meantime ill just put the Blown Motor. oops I already did it!!

 

now all the hard work starts with all the plumbing and wiring to do, maybe next spring ill get back to fixing the cracked inj motor.

 

i have always found that it's stupid to worry about breaking something that's already broke, go for it , can't break what's already broken.

 

THIS IS A PERFECT JOB FOR J-B WELD. Just kidding.

 

black pepper & jb weld

 

Can you really "solder" cast iron?