Hole in front of Engine block

A

alundsberg

Junior Member
Hi All,

I have a 31 Ford p/u. Not show worthy at all and really just used for occasional fun so I hate to invest in a new engine when it ran great and was recently checked over and was in great condition internally. About 10 years I noticed a crack so I put some JB weld on it. Worked fine until now. I pulled the radiator and front end off and the old weld just peeled off. I now have what looks like a wide long hole (similar to a coin slot on a vending machine). There is no mixing of oil and antifreeze so luckily the hole is just exterior and affecting the water jacket.

I thought about having it welded but I don't have the capability to pull the engine and take it anywhere. Has anyone had any success with using JB Weld or other epoxies for a hole like this? I've heard of others using Dexcon and Belzona 1111 but they are pricey and wondering if any better than JB? Or maybe I'm beyond the capability of epoxies at this point? Any suggestions or recommendations? Much appreciated.

https://imgur.com/CoOki79
 
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You may be able to have someone weld it up while it is in the car. Have them use a nickle rod and hammer on the weld with a ballpeen hammer to put the weld in compression. Normally the cast iron is heated before welding but if you hammer on the weld that is not necessary. Everything must be clean before welding. No paint, no rust, no grease, no nothing.
 
It sounds like the water jacket is starting to rust thru. If you could, post some pictures, it would help.

If the metal is too thin where the hole is, stitch welding probably will not work. You can clean the area real good and get the surface down to clean cast iron. Make a patch to cover the area out of 1/16 inch sheet metal. allow a 1/2 to 1 inch overlap from the crack. Clean the block and the patch until it is bright metal. Absolutely no oil, grease or rust. Use J B Weld to set the patch in place and apply more J B Weld over the patch. Let it set up well and fill it up with water and see what happens. If it holds, put some coolant in it or water treatment that will prevent rust and carry on. It may last several years and then you may have to do it again. It sounds like to fix it right, you may have to find another block if in fact it is badly rusted water jackets that are getting thin.

My opinion.

Chris W.
 
Just a quick tip in addition to what has been said, heat the area up beforehand to burn the oil out of the cast iron. It is very porous.
 
I just braze stuff like that. I've brazed motorcycle cylinders and all sorts of cast iron parts. A person has to carefully preheat and post heat slow cool down but the temps for Brazing are such that the heat is lower and low enough that a person can do the job without cracking it any further. A person may have to stop drill the ends but it depends on how rough the casting is on each end of the slot mentioned. Careful profiling can be done with a 1/8" or 1/4"carbide burr and a die grinder to smooth it some without removing too much metal if the slot is large enough. If not then just smooth it best you can with sand paper or a small hand held grit blast device using glass beads. Clean it well and clean again. Use a good flux and quality brazing rod.
http://www.stanymart.com/Vacula_VAC50_1061_Rust_Eater_Spot_Buster_p/26nvac501061.htm
 
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Hi Everyone,

Thanks for the tips and thoughts. Here are some pictures of it after I removed all of the old JB weld, grinded it down and cleaned it. Still trying to determine the best course of action but maybe these pics will help. https://imgur.com/CoOki79
 
Epoxy has a tendency to absorb moisture over time. Perhaps this is why the initial application of JB Weld failed? I think the silver solder approach has merit.
 
That appears to be a freeze crack, not a rust-through.
For a permanent fix, stitch weld, braze, or silver solder.
Epoxy products may work, as coolant isn't under pressure, but I wouldn't recommend.
 
You can play with an expensive epoxy and may get it to work for awhile but a silver solder PATCH job or TIG weld PATCH job will be permanent.
By "patch" I mean put a 16 gauge form fit steel patch over the crack area.
Applying filler metal directly to the crack is NOT a good way to do it. You need to be fusing or bonding to stable base metal back from the crack area at least 1/2 inch.
 
JB WELD it again .
Take your time and prep the area.
I put 2" clear tape to hold JB in place till it sets and give a second app if necessary
 
jerrytocci said:
JB WELD it again .
Take your time and prep the area.
I put 2" clear tape to hold JB in place till it sets and give a second app if necessary
Click to expand...

I agree.

That is a nasty looking crack. It appears to be that the cast iron may be very thin in this area. I would strongly suspect an very thin water jacket probably from rust.

You may be in for a different block sometime in the future.

My opinion,

Chris W.
 
Pete said:
You can play with an expensive epoxy and may get it to work for awhile but a silver solder PATCH job or TIG weld PATCH job will be permanent.
By "patch" I mean put a 16 gauge form fit steel patch over the crack area.
Applying filler metal directly to the crack is NOT a good way to do it. You need to be fusing or bonding to stable base metal back from the crack area at least 1/2 inch.
Click to expand...

Agreed here! Thats a big one to deal with. I'd pull the motor and situate such that you have as leval an area to work as possible so you have the best control. Silver solder a short segment at a time, and let the heat out between segments be patient and you will have a lasting fix. Keep heat buildup at bay, or it will crack.
 
I must be in the minority here, but with the number of blocks that seem to be available, why would you invest so much time and effort in fixing that freeze crack. It's your money, your choice. If it were me, I'd find a better block.


Frank
 
It will take a lot of silver or bronze for that. It's repairable but I think I'd start looking for a better block. That's a big crack that would require removal of the engine for effective placement to get a good repair on it. I wouldn't try it in situ and it can't be cleaned inside effectively.
 
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alundsberg,

Attached are photos of a Diamond B engine that l did a crack repair on about 35 years ago, l used 1/8" solid brass plugs, 11 of them, starting on each end and worked towards the middle, drilling half into the crack and half into the plug. Many years later Pete recommended that l use Cast Iron Plugs to prevent dissimilar metal expansion.

Darryl in Fairbanks
 

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