Cracked Block

[Mark Millbauer]

I have a spare motor that I hoped to rebuild and when magnifluxing the block found tow cracks in the water jacket side cover mounting holes. One of the cracks extends about 3/4 of and inch down the block. I tried to upload a couple pics, what do you think? is this block toast? Is it worth trying to have pinned or welded?

Mark
C27 Solution

[Qben]

If the block is in otherwise good condition, you might try www.locknstitch.com They have a product called "Full torque" which would probably be ideal for your situation. Give them a call on the tech support number with the thickness of the block in the area of the crack and maybe one of those pictures already attached to an email, ready to send. I'm not sure how much it would cost, but they could probably repair it for around $100 if you shipped it to them.

The other alternative is to find someone who deals exclusively in cast iron repair. Ask around at the reputable local machinists, call far and wide if necessary. If it's going to be welded it has to be done properly in an oven with the required heat up and cool down procedures taken. Don't trust it to anyone who won't guarantee their work and who doesn't have many, many years welding cast iron with a spotless reputation. If you can find someone like this, the repair may be around the same price, but without the shipping.

Hope this helps.

Qben Oliver

[Mark Millbauer]

Thanks Qben.
I remember seeing the website for the Locknstich folks (I think it might have been through this forum) and it did seem interesting. The problem with welding it which can be done, is that the block has to be heated to such a high temperature that after wards the block would have to be decked and bored. As you might imagine, this would add a lot of expense to the rebuild. There are some that woudl grind it out a bit and fill with JB weld but I'm not going to put all the time and money into a block that has JB weld holding it together.
Sad part was that when I picked up this motor as a project, I fired it up after sitting for 10 years and it ran like a top with an average 110 lb compression. The starter cranked, the water pump pumped, the alternator put out 13.8 volts and the carburetor worked fine. I just wanted to go through and re-fresh things since it was out and on the bench. Perhaps Don will chime in with some of his words of wisdom.
Oh well, if the block is not worth it, at least I have a bunch of extra parts.

The enclosed pics are of it on my test bench before I dismantled it.

Mark

[Mark Millbauer]

I apologize for the size of the pictures in the last message. I forgot to re-size them. I'll try again.

[Qben]

I can certainly understand the reluctance to heat the block for welding.
That's a pretty nice test bench you made. If I had to guess, I'd say you've done this before!
Qben

[67c&ccorv]

I would think that if those cracks didn't leak when the motor ran before then the block could be reused.

It's not as if the water passage ways are under extreme stresses as you would find in the head/cylinder combustion areas.

I wouldn't throw it away - yet.

[lat 64]

Keep it

Yea, What he said. Don't throw that puppy away. If you do, throw it my way
A mechanical fix should work just fine there. I wonder how it got that way?
Even if it weeps a little it will still get you home. But I'm sure it can be sealed. Thats a non critical place.
Any antique car clubs near you? They'll fix anything. I bet they would love a chance to help out.

[Don Moyer]

Mark,

I cast my vote with those who urge you to continue on with your rebuilding of this engine. Location of a crack makes a tremendous difference in how it can be approached. If these cracks were in an exhaust port, across a valve seat, or some other high stress area my advice would be entirely different, but cracks in this area can be approached more like a "leak repair" than a serious crack repair.

If you clean the area around the cracks down to the bare metal, one of the small West Marine fiber glass repair kits should work well in this area. Follow the instructions in the kit regarding the use of the glass dust until the epoxy looks like the consistency of thin mayonnaise for best adhesion.

Assuming this block is as good as it appears to be otherwise, this engine could turn into an heirloom to be enjoyed by your grand children.

Don