M37 block

[Karl kostman]

Hey guys I bought an engine out of an M37 its 100% stock and I got it for not to much money and it runs fine. I had it running in a chassis and when I shut it off and went into the house for a couple hours and when I cam out there was a very small puddle of water under the engine, I started looking things over and found a crack in the block its very tiny but its looks to be about 3" long and there is a very small weep of coolant coming out, I would like to fix it with one of those solutions you put into the cooling system and it finds the crack and plugs it (for lack of a better description) Do you guys have any thoughts on which one of these sealing solutions is good, and works?
All ideas appreciated!
Karl

 

[NDT]

If I was considering a non permanent repair, I would notch out the crack a little and fill it with JB Weld.

 

[G744]

The expensive blue leak sealer.

 

[John Mc]

I've always wondered how those sealers know not to seal up things you want open, like the passages in the radiator or heater, or other small passages.

 

[Karl kostman]

Thanks much guys and I do agree with all your responses but will try the blue leak sealer they do claim its a permanent fix, guess we shall see? Thanks again for your assistance!!

 

[gringeltaube]

I've always wondered how those sealers know not to seal up things you want open, like the passages in the radiator or heater, or other small passages.

Not the sealers! It's the sellers who know... And you better believe what they claim since they always tell the truth...

 

[G744]

I've had good luck with that blue stuff in Diesels by Mercedes, Ford, and Detroit.

Seems contact with dry air causes it to coagulate and seal up. Kinda' like humans do when cut...

 

[M37M35]

I would notch out the crack a little and fill it with JB Weld.

This is the way I'd go.

My dad and I have actually fixed some pretty large cracks in blocks and heads this way, and it does work. Some of these fixes are 30+ years old and still in service!

I've always wondered how those sealers know not to seal up things you want open, like the passages in the radiator or heater, or other small passages.

Me too. I don't use the stuff.

 

[87cr250r]

JB weld can work. Drain the coolant, end drill the crack, V out the crack, clean clean clean, then apply. Most people will skip at least one of these steps which is why they get bad results and then blame the epoxy.

The right epoxy properly applied should be permanent. Be wary that the temperature ratings in water are quite different than what is on the label. For example, Devcon's epoxy available at parts stores says 250°F on the front of the package but it's only rated for 120°F in water.

There is also Lock-N-Stitch if you want a permanent metal based repair.

 

[G744]

I've used Nickle 88 rods for welding cast iron, had decent results there.

 

[Karl kostman]

Thanks much for your input guys I got the repair made and pressurized the cooling system to 10 psi and it held pressure for 90 minutes with no visible signs of any leakage. I think I can work with that!
Thanks again for your input!

 

[M37M35]

Thanks much for your input guys I got the repair made and pressurized the cooling system to 10 psi and it held pressure for 90 minutes with no visible signs of any leakage. I think I can work with that!
Thanks again for your input!

Good deal!

How did you end up fixing it?

 

[OutpostM37]

I had a crack in the M37 230 engine exhaust manifold. These exhaust manifolds are expensive compared to the intake manifolds. Maybe because the exhaust manifolds are prone to cracking.
My rebuild shop has an ultra fine metallic powder that has an iron and zinc compound. They welded the exhaust manifold and it has been working perfect for 4 years now. They charged me $75 at the time. I hand carried in the exhaust manifold to the shop.