The Stovebolt Site Forums The Shop Area Engine Shop Cracked block - need direction on swap or replacement

Hi all.

I have a 1941 1.5 ton truck with the 228 motor, and I'm located in Western NY. I noticed a crack in the side of the block that is leaking antifreeze pretty good, I was hoping for suggestions on three points.

Any idea/suggestion on a repair? I read a few forms on here about using extreme temp JB, which is my current plan. I called multiple engine shops and places that specialize in cast iron. No one wants to touch it or will guarantee their work.

Does anyone have a line on a replacement block or where I should begin to look?

I read the motor is pretty hard to find, so I was also considering a motor/tranny swap. Any idea, or suggestions on what might work? Shower thought was for a 350sbc and manual trans, something that would make driveability much easier. Maybe the drive line out of a Chevy pickup?

The truck is a fire truck, all original and in really great shape, it's a real shame this happened but I'm guessing it's been this way for years, if not decades going back to when the fire department owned it.

Thanks all, appreciate the help.

I think every stovebolt ever made cracks there and leaks. As long as it's not mixing with the oil you can repair it with JB Weld. Next time you're at a Stovebolt ralley, look at the inline sixes. Probably half will have a JB Welded crack in that location.

Mine has a crack in the same location and a previous owner epoxied it up. It's ugly but doesn't leak. If you take your time you can replicate the look of cast iron by imprinting the repair with a sponge or something. Once painted it's hard to notice.

That crack is VERY fixable, but the engine will have to come out to do a good job. I'd suggest a product called "Marine Tex"- - - -it's much better than JB Weld, which has a tendency to rust due to the steel dust they use for reinforcing the epoxy. Marine Tex is designed for wet environments. Smooth up the area for 1/2" to 3/4" on both sides of the crack with a flap wheel in a small angle grinder to remove the casting roughness, clean the area thoroughly, and lay the block on its side with the crack facing up be sure no coolant can creep under the patch while it's curing. Just before the patch material cures completely, press a piece of 40 grit sandpaper firmly over the surface to put the casting texture back into place. The patched area will virtually disappear once the block is painted. Older cooling systems such as yours run a "zero pressure" radiator, so there won't be any worry about internal pressure pushing coolant past the patch. All you'll be fighting is gravity and heat expansion. Good luck! I've got a good 228 engine in the core pile if you are willing to make a road trip to south central Tennessee! 248, 256, 270, and 302 GMC engines would be a virtual bolt in swap if you're willing to go with a "non-original" engine.

Another rust resistant patch material is Devcon Epoxy Aluninum, but I'd reccomend Marine Tex as the first choice. If there's a marina or a boat repair shop nearby, they might even have some on the shelf. Otherwise, it's all over the internet.
Good luck!
Jerry

I have used waterglass (calcium carbonate IIRC), used to preserve eggs in years gone by. It stopped a leak in a 389 Pontiac V8 that I couldn't find even after completely dismantling the engine. One must drain the block for winter as the waterglass is rendered ineffective by ethylene glycol antifreeze and it will begin leaking again.

Dropping a SBC in will not be an easy or cheap fix. The parts needed to move the water pump up so fan doesn't hit the fire pump drive shaft may be hard to find. Under the hood space may also be tight for any fire equipment needed to prime the pump.

Make sure you think it all out before you tear it apart...there's a lot going on with a fire truck...converting lights and siren from 6 volt to 12 volt comes to mind.

Mike B

A 235 block crack in the driver's side water jacket. A slow weep of coolant.

Patch job with fingers crossed:
Drain coolant into buckets/containers.
Drill small holes above and below the crack into the water jacket to stop crack spreading.
V-groove the crack to expose more area.
Steel brush the block to remove rust and loose particles.
Work JB weld into the holes and groove.
Cover JB Weld with plastic wrap.
Wedge a block of wood to hold JB Weld and plastic wrap in place against the block.
Allow to fully cure.
Remove wood block and peel off plastic wrap.
Pour coolant back into radiator.
2010 to 2022 and still counting.

I just did exactly what Jerry suggested with my ‘37 216
Worked perfectly I drilled small holes at both ends of the crack
to stop it from spreading

How deep/large of holes would they need to be to properly stop the crack? An I looking at 1 inch deep or 6? I'm just worried about going to deep and damaging something else. Other than that it sounds like this isn't as bad as I thought. I started draining the coolant yesterday but I haven't found a way to remove it totally from the block. I tried using a vacuum/compressed air to "dry" it.

I have been in on a couple block repairs. One was so bad about 12 sq inches had fallen off the side of the block due to it not being winterized before it froze.

We ground into the crack or beveled the edges of the fall out piece and wire welded it into place or filled the crack with weld. Then we cleaned around it very well and used JB weld to seal it tight. Those boat engines are probably still in service today.

We never tried to blend it in, but if you are going to paint that is a great idea.

kcolg No one mentioned it but you could "sew" that crack up with tapered iron plugs made to fix a gash like that. They wedge it tight so it will stay,company in California will do it,or do your own. Saw those plugs 50 yrs. ago so not new .

When you drill the holes you can feel when the bit gets through the outer wall of the water jacket.
I don't think it was much more than 3/16ths - maybe 1/4"

To be on the safe side, angle the drill upwards.
If the 228 is anything like the 235, there is an oil passage below water jacket (red rectangle).

Oh Oh. Does a ‘52 216 have that oil passage?

This Pontiac I6 engine was repaired as Jerry suggested 12 years ago and still trouble free. The crack even ran into a freeze plug hole. Sand blasted to bare gray cast iron, roughed with 24 grit one inch on each side, and V grooved along crack and covered with Marine Tex. Used expandable rubber freeze plug.

[img]https://i.postimg.cc/p9Hmtpzj/40-Pontiac-engineand-trans-002.jpg[/img]

'37 barn find. Same passage for your oil pressure gauge connection.

kcolg Also had a 235 truck with a freeze crack full length of the block hi-up behind manifolds,someone fixed with epoxy,never did leak,ran it a lottoo !!

Thanks everyone, I ended up doing a combination of several things. I dremeled the crack to be a little larger, made two small holes at the end of the crack to hopefully stop it from spreading then I used extreme temp JB weld and covered the entire area. So far so good, it's holding the water in.

Good save!

You can PM me if you end up resorting to and wanting a block. I have a 228 that I can let go - it’s just taking up space. PM me for contact information. I live in northern NH.

But, yes… monitor the repair and let’s keep fingers crossed it lasts and it works for you. Nice job.

Years ago I had a 6" crack that leaked coolant in my 1954 Chev. Pulled the engine and took it to a blacksmith who drilled each end of the crack and then welded it. Not beautiful but it never leaked again.