Model A cracked block

[31atheway]

Hello.. trying to get some info and perhaps suggestions. I have a cracked block.. attaching pic. looks like someone tried some Jb weld at some point. I am told that the issue can possibly be tig welded. By adding a plate over damaged area.. an automotive machine shop told me they might be able to fix it but cannot guarantee it will work .. they were very upfront. First they will charge $75 to cut a hole around issue and check strength of wall If not enough meat on the bone I out $75 and have a block with a bigger hole in it .. if they think they can fix it may be another $300 to $400.. So question is. Try the fix for $500? PLUS cost to rebuild engine ... Or short block for 3 to 4 K? May seem like a no brainer, but if tig doesn’t work I have to pull engine again.. on the surface doesn’t seem like a big deal to try to save a few thousand.. any thoughts please?

Have engine out.. dropped pan and pulled head. Engine looks pretty good for 90 years old.. and turns freely so maybe an option is to try tig and try engine asis, with some cleanup, just to see if it works and rebuild later .. Have not checked compression

[Shelbycsx]

If it's a numbers matching motor fix it. I would braze it.

[jb-ob]

Fix it right the first time......if the block is that valuable to you.


Depending on the 'talent' in your neighborhood, first step is to have it magnifluxed looking for other freeze cracks.


The best repair is to have the cracks pinned. A piece can be pinned into that back hole was well.


Only you can determine what it is worth to you.

[Gold Digger]

I don't know if you may have another crack some where else but I fixed a jeep block 32 years ago that was worse than that with bondo. Still holds water under pressure.

[Synchro909]

Because the cooling system in these cars is not pressurised, a repair there does not have to be very strong. Let me ask this: How long has the JB repair been there? If it was done by a previous owner, how long have you had the car? Was it leaking?
While the comments about fix it right are fine and likely will give peace of mind, I'd consider another repair like the one you already have but I'd first see if there is some material available these days that might be better than what was used first time round.
If this is not an engine that means anything special (like matching numbers), I'd ditch it and for waay less than he repair with no guarantees will cost, buy another block for your rebuild.

[Pete]

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Assuming the block has no other problems, I would trust a TIG weld patch any day if done by someone good at TIG welding cast iron. Ask to see a sample of their work. Here is one that was done 20 years ago and is still circle racing.

[Jack Shaft]

Patch and run...what ever you decide the flywheel housing,if un cracked is an after production 'service' housing..the last and best design

[duke36]

You may get a lot of responses and search the Forum, so perhaps await a few days. Cast iron is very tricky to weld and usually needs to be furnace heated . Heed advice above.. The block appears to be worn thru with not much metal thickness, not a crack which can be a candidate for metal stitching followed by overcoating with a professional grade epoxy such as Belzona. Some sources suggest that threaded pins used in stitching may leak but have no personal experience. I sealed a prior repair with JB marine weld, and it didn't hold up well to hot water migration.

[Pete]

Originally Posted by duke36

You may get a lot of responses and search the Forum, so perhaps await a few days. Cast iron is very tricky to weld and usually needs to be furnace heated . Heed advice above.. The block appears to be worn thru with not much metal thickness, not a crack which can be a candidate for metal stitching followed by overcoating with a professional grade epoxy such as Belzona. Some sources suggest that threaded pins used in stitching may leak but have no personal experience.

DO NOT allow anyone to furnace heat it or you will be re-machining every machined surface on the block. That means the mainline, camline, lifter bores,
guide bores, pan rail, head surface etc etc etc.

Local area heat to no more than 200 degrees is all that is needed for TIG welding.

[johnneilson]

Pete,
do you know what alloy rod was used?

J

[History]

I had a retard try and Weld mine, what I received was a retarded job. Make sure whoever tries it has attempted a Weld like this before so they understand. It can be done but not by a retard.

Yeah I know, not pc but true. Mines on the front of the engine and a patch could save mine as well. I never considered a patch. Thank you.

Maybe I'm a retard.

[Russ/40]

Your problem is not a crack. Your problem is rust so bad the blocks to thin in who knows how many places. Don't give it a seconds thought. Run away from that one.

[dumb person]

If it were possible. You might be able to avoid heating it by cleaning the area, JB weld (epoxy) a patch over it and drill a series of small holes around the edge, then tap for very small bolts.

That's the sort of thing i'm forced to do. It's not as bad as people think.

[john charlton]

From the picture this looks like a rust hole from the inside of the block . This is a favourite place for rust through I have seen the same damage in other blocks . This means the block is thin elsewhere. If it were mine I would not attempt any weld repair you will just chase the hole around the block and then it really will be junk . First clean all rust out of the block a good vacuum cleaner magnetic screwdrivers etc etc . Clean the back end of the block and make up a large steel or aluminum plate to suit well covering the damaged area. You will have to take you time to find wall thickness that can be drilled and tapped . When you have made everything and ready to go mix up some JB Weld and coat the patch and bolt it to the block . I would use coarse thread 3/8" short bolts no washers required spaced about 2" apart just common sense really . Use a good antifreeze to halt further rusting .The patch would not be seen when the engine is in . You will have to put a dimple in the patch to clear the bracket bolts . Could last for years and years and a cheap repair .Worth a try for sure .

John in sunny morning locked down Suffolk County England .

[31atheway]

Great responses everyone.. gives me a lot to think about.. I have only had the car for about 6 months. Has not run in years as i understand it. Bought it from a friend of mine who had it sitting around for decades. Car was actually his dads. the numbers do not match.. engine / frame .. I now concerned that it may be rusted out or weak in other areas. I’ll dig into it.. I have car totally disassembled.. engine trans out. Have been restoring frame, front end , rear end , steering and brakes. Can’t ignore power train much longer. :-) .. I am leaning toward another block but will dig into this one a bit further .. this is my first restore so learning as I go., have ‘how to’ books which are helpful, but as dad used to say .. no substitute for experience Thank you all for you responses

[daren007]

Check your bearings. If they need work then you know the next step. Blocks are easy to find.

[Ed in Maine]

I would guess that John Charlton has the answer to this one. I would use a 1/8" thick plate. Pray that there is enough metal to drill and tap on the ends of the damage. Use Locktite on the bolt threads, you don't want this to get loose. Use plenty of JB Weld so that it comes out all the way around the plate. The best part of this repair is that you will not have much money invested in the repair. If it doesn't work, you can say I did the best I could with it. Good luck, Ed

[bobbader]

In my opinion, you're working in reverse, thinking that this may be the only problem with this engine and a patch will have you going merrily down the road. While many would dismiss this block right away as not worth the effort, only you can determine the effort you want to expend and $$$$$ you want to spend and whether this is necessary given it's a non matching number unit, hasn't been run in years, etc. If you're dead set on making the gamble, the wisest choice is to disassemble everything, degrease the engine, take it to a reputable shop, see if it can be magnafluxed as is, or will need further degreasing and rust removal before doing so. My guess is that, even before you get to the magnafluxing, you'll find enough other reasons to abort using this block. If your intention was to have an engine rebuilt, find a rebuilder who is well known and trusted on this site or through club members or other owners and start fresh. Many rebuilders will have a stock of rebuildable core blocks or complete engines at "going rate" prices that make searching among piles of other unknown used engines a useless process. After 40+ years in this business I can only tell you that if one mechanical item on an unrestored car has an issue like this rust hole in your block, you're search will most likely turn up other concerns. If after disassembly, cleaning, bead blasting, and magnafluxing, someone deems this engine OK to use or rebuild, go for the best possible scenario of repair that others have suggested.

Good luck,

Bob Bader

[burner31]

Every time you drive it you will have that patch/repair eating the back of your brain.
Get a "good" block, and move on from there, numbers don't match already so what's the issue.
Just a thought

[eagle]

On another thought, you mentioned numbers dont match. If it was my project, id make sure all numbers match, including the title. Better to do it now while its all apart. It can be a real can of worms later. You should be able to find a good rebuildable block for a couple hundred bucks or so. A stamping set isn't expensive either.