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What is the best way to repair a cracked block on water jack drivers side on 57 235 Chevy t

pjberg,
There are many opinions on your question. Just do a search and you will see. Personally, I went the way of loc-n-stitch. No matter what route you take, make sure you correct the problem that caused the crack in the first place. Probably mud laying in the bottom of the water jacket and preventing antifreeze from protecting that area. Look at my repair in my photobucket. I am very satisfied with the results.
Good luck!
Jim

The block has some rust in it

Here is the question of the hour. The block has a crack a mile long. There is rust in water jackets. Is it worth fixing or find a different block.

....is the engine still in the vehicle? Does it still run well??
if yes to the above questions drill a hole at the ends of the crack and have at repairing it. Nothing to loose much to gain.

The engine is on the stand I was told it ran good. I just bought the thing. I have the head off and when I pulled the drain valve out nothing came out. Even thou I got a half a gallon out with my sucker

The back drain plug is notorious for being plugged. Take it out and poke a wire (coat hanger) around up in there and see what you fish out....or can flush out once you get it opened up.

Pull all the freeze plugs and poke as much of the crud out of the block as you can with a piece of stiff steel rod, soak it with a mild muriatic acid solution to loosen the crud in the water jacket, then pressure-wash everywhere you can reach. Having the head off is a huge advantage- - - -it gives you access to cooling passages you wouldn't be able to reach otherwise.

Once it's clean you can make a more informed decision about whether to try to salvage this block or look for one in better condition. Also check the bore size and cylinder taper- - - -if it's going to need a rebore job, start looking for a replacement block.
Jerry

The thing turn over nice and easy, the cylinders look nice and shiny but cylinder 2 has a small groove and I can catch my finger mail in it. So from that it probably needs boring?

If this was a rare antique engine there would be no question that you would do whatever it takes, but this is a 235 Chevy. After all the work and expense you will have a patched 235.
Get a sound block and move the project along.

While you're looking for a replacement block, try smoothing the area for about an inch on each side of the crack with a flap wheel on an angle grinder and apply a layer of Marine-Tex sealer about 1/4" thick. As it's curing, press a piece of 40 grit sandpaper over the surface of the patch to duplicate the texture of the cast iron. As long as you don't use a high pressure radiator cap, the patch should be leak-free. I believe the cooling system on your truck uses a 7 PSI radiator cap, which should be OK. You might decide that after cleaning out the crud in the water jacket, you don't really need to swap engines right away.
Jerry

Thanks again for posting this procedure again, Jerry

I read it with great interest. I have a spare "matched pair" 1954 3100 Hydra-Matic engine/transmission. If my working/running/rebuilt pair give-out, I like the odds of being able to use the engine-block which has this type of crack in it. It was originally spec'd for 4 PSI thermostat.

What is the chance that the crack is from freezing-expansion due to inadequate anti-freeze?

That's the most common cause of a crack around the area of the "freeze" plugs- - - -which, BTW, aren't intended for freeze protection. The holes are there so the foundry can knock the casting sand out of the cooling passages after casting the block, then the holes are machined to accept steel or brass plugs. They are actually known as "core plugs". Sometimes the plugs push out when the coolant freezes instead of the block cracking, but it's not guaranteed by any means. The nice thing about an external crack is that it doesn't have to seal compression or combustion pressures. A patch that can stand cooling system pressure without leaking is much simpler to do than fixing a cylinder head or cylinder wall crack.

It's also possible to have an internal cooling system crack that puts coolant into the crankcase, but it's not as common as getting damage to the outside of the block.
Jerry

I wish I could find a way to put up a picture. I find on eBay a block only for 430$. It's a 3837004 block 3701887 head

That is a 1953 head.
That is a 1955-57 block.

They will work together OK.
Most likely the head takes a 2-bolt valve cover?
If so, get the valve cover.

What is the head casting code on your 1957 235?
Most likely it is 3836848 - a high compression head (preferred by many people).
It can be used on that 55-57 block (it was used from 1956-1962) .

I do live in minnesnowda and thanks for the responding to all

That what I have and the one on eBay in Albert lea is also a 3837004 for just the block they want 430. So the cost of fixing verses or different block

It might be a good idea to check out Craigslist- - - -sometimes those guys in Albert Lea think they're selling gold instead of cast iron. I've been GIVEN several complete 235's to get them out of the way of some of the places I do business with.
Jerry

A cracked water jacket on a 216 or a 235 is not the end of the world. Usually they just seep a bit. Bars leak in the radiator usually stops the leak completely for a year or two. When it starts leaking again after 2 years, its time to flush the system anyway, so do that and add another dose of Bars Leak. Would I rebuild one which was cracked? No. Would I try to get every last quality mile out of one of these gems? Absolutely.
Carl

$430 is way too much for a bare block and head.

No that's just the bare block. $430

I hope that deal includes a big jar of Vaseline and a wet, sloppy kiss!
Jerry

Hello Tim,
I've have the same problem as you. I have a 3837004 block which is cracked at the water channel. I gave the block to a motor services, that should look if they can weld it.
If not I have another block 3835911 which I planed to restore it with the complet turning parts of the 3837004. I will measure it and I hope I can use all turning parts with out the water pump.
pictures of the two blocks, you find here:
http://www.kripahle-online.de/unterricht/?page_id=2408
Wolfgang

Actually there are lots of people out there that wish this old 235 sitting in their shop was gone! I've found these folks on the TriFive.com site, first order of business for the majority of them is to pull the six for a V8. I'd sign up and put a wanted ad for the 235. Best of luck