Technical Advice Needed Cracked 49 Mercury Block

I have a 1949 Mercury engine put away, it was a good running engine when I put it away, with the intention of rebuilding it one of these days. Well, the day finally came, and I started disassembling the engine for pressure testing and magnafluxing. When I removed the driver’s side water pump, I saw what nobody wants to see, a couple of freeze cracks in the block. I thought I had drained all the water out of the block when I put it away but not so. My question to more knowledgeable people than myself. Can the block be repaired, if so, is it worth the cost especially now that good blocks are getting harder to find. Also, I live in New England would anyone recommend someone I may contact about repairing the block?

 

Wow that's a lot of crack. I'm sure it can be fixed, but it might cost a lot. Since the front surface is not smooth anymore, could the offset area be built up with braze and machined flat again?

 

That is one hell of a crack. Seens like multiple fractures which is not good for the integrity of that section. Sure, someone with the skills could fill the area with braze material, but will it work, only you will know once everyting is done. As @alchemy said, block will need to be squared up on all critical mounting surfacres. After all that, and the chance it will not be fixed, not sure I would go down that path.

 

I dont know where in New England you are but I had called Springfield Crankshaft and Engine Machining in Chicopee MA about doing some work for me. Guy sounded knowledgable about flatheads and also said they use a guy in Worcester MA that does some pretty elaborate block repairs for them. So I dont know. I never got my engine over there due to various covid related obstacles.
Disclaimer. I havent had these guys do any work for me. I dont know them. But thats what Ive got man. Good luck

 

If that was my block, I would be looking for another one. It looks to be cracked along the pan rail in addition to that massive crack at the front of the block. Cracks in the pan rail almost always are the death knell to a flathead block. The cost to fix that block is going to be greater than the cost of another block.

 

Thanks for everyone's comments, that was also my thoughts.

 

Good blocks are out there. I thought finding a good one was gonna be a drag. I "networked", found three good ones pretty quick a couple years ago.

 

We took a '63 Cadillac block to a machine shop to have it checked, knowing it had a freeze plug pushed out behind the flex plate. Got a call from them, the guy said, "Do you have a boat?" Having a nice wood Chris Craft runabout, I said "Yes, I do", thinking he wanted to talk boats.
"Well", he said, "You now have an anchor."
That sort of applies to your situation. Do you have a boat?

 

I think you made a wise choice. I think if you considered taking the block in, stitching it up, welding etc, and look at that cost vs finding another, you’d be money ahead with a known good block.

 

Humbly. I appreciate everyone's comments, if a kind sole has a known good Mercury block for sale in New England, I hang my hat in Rhode Island, please let me know..

 

Ford and Merc blocks are the same 49-53, truck and otherwise.

 

As far as I know, a Merc block is no different from a Ford block—both supposedly a product of FOMOCO!!

 

Take a steel plate and bolt it where the oil pan goes, drill small hole at end of crack. Gently V out crack,don’t go ape ! Jig and clamp and weld a cradle as needed utilizing block holes as needed. I mean weld a temporary cradle to hold things in place but not in the way of brazing the damage. Find a old stove , modify it to accept engine block. Pre heat block in the old stove for 2 or 3 hours . Have a little help, pull it out braze that som-bitch up—- place it back in and bring the temp down slowly. Here’s a transmission plate a kid broke. I drilled and positioned steel pins like rebar and v-d out so the brass would work around the steel pins and cast iron. It’s keeping him going until he finds another —If he can find one!!



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Either buy another Flat Head or put a Chevy in it & Drive it.!

Just my 3.5 cents

Live Learn & Die a Fool

 

Back the camera away a bit and post up a better photo of where the damage starts and stops. Around here you can pay around 1K for a usable block. If it were my own block I wouldn't back away from the repair as the photos show it if it were in fact the only place it's cracked. If I were actually looking and inspecting the brake I may not make the same decision. I have repaired external water jacket cracks without welding at all. Major decision maker is what's the motor worth and what's your time worth.