Technical Welding a cracked block

Hey guys
I picked up two flatheads today for my project and I think I got pretty lucky in that neither block has any of the typical valve to cylinder or pan rail cracks.
Unfortunately I did find a crack in the side of the block that I am concerned about.
I am assuming that a good welder can fix this? It doesn't look that bad to me but I know welding cast can be tricky.
It's a 1953 merc(ford) block.

 

Lock-N-Stitch

 

ditto

 

Or, you can clean and V the crack a little past the crack and use Hi nickle rod and and a stick welder and weld about an inch at a time, then Peen it with a peening hammer. That may be a little too old school though.

 

That's what I was thinking but it's been so long since I did any stick welding work that I didn't want to wreck the block.
The lock n stitch is interesting, I never knew it existed but I can see how it would work.

 

You could weld it with nickel rod but Lock-N-Stitch sure looks like the way to go
if you don't feel confident welding.

 

Do the lock and stitch, trying to weld that old contaminated cast iron could likely turn into a disaster.

 

I’ll look around tomorrow in my garage and find it. I recently bought some rod they recommended to me at the old auto parts store I go to that is specifically intended to weld dirty old cast iron. He said that it was intended to weld things like exhaust manifolds.

 

You stirred me to action. It’s Forney Nomacast





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You still have to stop drill the ends of the crack no matter how you do the rest of it.
A bit of info on the Nomacast rod https://www.wasatchsteel.com/product/43401-nomacast-hard-cast-iron-electrode-1-8-1-lb/ That you might find interesting.

 

I have welded , brazed , cold welded cast iron . Where your crack is located , I think I would braze it . Second choice would be cold Weld , last choice would be tig Weld it . I really think , JB Weld would repair the crack after end drilling it , where it’s located . Your choice , clean it , clean it and clean it again before trying anything

 

You could always take the block to a large diesel, heavy equipment, or farm implement shop; those are unique and expensive parts that are frequently repaired as opposed to replaced. That's what I would do if I did't have the skills or trust in my work. I am Butch/56sedandelivery.

 

Had a Ford yblock that was cracked in the middle just below where the motor mount bolted to. Sent it to a place that was recommended to me. Did a great job. Never had any problems with it.

 

Thanks everyone for the input, the metal stitching process is interesting. I can't find any pricing online so I shot an email to lock n stitch for a quote.
The crack is approximately two inches long and very tight. If it was in a existing built motor I might be inclined to try some magic in a bottle to seal it.
Since it's out, disassembled and will be reassembled with new parts I would prefer to be confident in my chance of successfully fixing it.

 

Keep us posted on your plan of events and the outcome. Im watching.

 

If you decide to weld or braze it, heat the block as hot as you can.I have heated blocks over a camp fire before then bring them in the shop with the cherry picker and turn my rose Bud up on high under the block to keep it hot.
You will need to grind a vee in the crack the same approximate width as the iron is thick. Weld from one end of crack let it cool, stabilize the temp then weld from the other end of the crack. Repeat till the crack is welded. Sometimes the blocks are not thick enough in some areas for the stitch method.






Bones

 

Update, after checking out all the suggestions, talking to a local welder, a couple buddies .....you know the drill. I decided to try J.B weld. I drilled the ends of the crack, v'eed it out, filled it and textured it with a sponge. You couldn't hardly tell it was there.
Probably would have worked but I started second guessing whether I would ever really be confident in it as a fix.
I happened to mention it to an older gentleman I know and he suggested brass screws/bolts were the old school fix.
Sounded good to me so that's where I ended up. Picked up a handful of brass machine style screws, drilled and tapped them in so they overlapped (I did use some JB weld on the threads).
Went really well and I am more confident that it will be a lasting repair.
I always appreciate it when folks update their threads with results so I will let everyone know how it turns out once I eventually get it running.

 

Hmm. Interesting way to do the repair. Hope it lasts and works ok for you.

 

Is that possibly a freeze crack? I'd be looking real hard for more cracks in all the bores, etc, and etc.
Others probably know the weak spots.
I'd probably even think about rigging up to do pressure testing, and even then use up a couple of cans of dye penetrant and developer.

 

So basically, you did your own version of the lock-n-stitch method, only using brass bolts. I don't know how/what the dissimilar metals (cast iron and brass) will have on your repair, as they have different expansion/contraction rates, but hopefully, it all works out for you. And probably a lot cheaper to do. Keep on posting! I am Butch/56sedandelivery.

 

I had similar thoughts on the coefficient of expansion between the two materials. In fact that is really my only concern with the repair. I don't think it will leak as it is but if the brass stresses the cast through expansion I suppose it could cause another crack.
Time will tell I guess.

 

I've gone over this block as best I can, valve pockets,cylinders, pan rails, webbing and the only cracks I can find are this one and one crack between a head bolt and water jacket hole (typical).
Not sure how I could rig up pressure testing on a bare block.

 

Ive went both ways, welding (which I prefer) and the second crack I drilled a small hole at both ends of the crack, V'd it out and jb weld filled. Both lasted with no problems.

The jb weld block was a 389 in an old GTO that I rebuilt and seen 5500 rpm alot, never had a problem after 2 yrs and it was my daily driver, seen it all the time for 2 another yrs after I sold it then lost track of it, still no problems.

 

You can TIG weld it with 309L it does a beautiful job be sure to pre-heat and drill the ends of the crack. 309L welds nice but it’s a bitch to drill and tap. I learned the best way to do a threaded boss repair is to thread a carbon rod and screw it in the remaining part of the hole and then build up around it then take the carbon round out and chase the hole.

 

A crack in a block is like a crack in thick ice. What you see is not always the problem. What you don't see is what you should worry about. Cracks are the result of molecular shifting from thermal expansion and contraction. If the block is worth a plug nickel tests can determine the extent of the damage. Magnafluxing, pressure testing, X-ray, etc. would be a step in the right direction. I know there is disconnect between theoretical causes and effects, and the real world of dollars and cents. Filling the gap with plastic mud, to my way of thinking, is a waste of time --- because at some point it is going to let loose; and trust me, Murphy's Law applies to putting yourself up the stinky creek from shoddy repair work. Some old timers drilled and tapped the gap and filled the crack with good solid metal. I have seen old tractor blocks from the forties and fifties that had so much brazing done to them they were covered with brass. It all depends on how far you are willing to extend yourself before you quit seeing something as repairable and see it as a boat anchor. This is just my two cents worth.

 

Back in the late 70's the family owned boat with a 350 chev/ mercruiser was neglected & the the block cracked in the usual spot just below the side frost plugs , about 4" long . Friend of mine worked in a foundry & brought me some eutectic DC hi nickel content rod , drilled it , v'd it& welded it , wire brushed it then used an epoxy called "Marine -tex " . The boat is still in use 40 years later & has been trouble free ..

 

In the old days , a farmer keeping the tractor going for another planting or harvest might well have been the difference in surviving or not , regardless of the method or material , same holds true between enjoying an old engine/ vehicle , or sitting on the front porch watching others...

 

Well keep us posted, might be just fine. Time will tell. Thanks for the update.

 

Why would brass screws be any different then brazing? Both the same material.

 

Cool man, looks like a good repair. Please follow up after you get it running.