MTFCA Forum

Greetings Everyone:

RE: Water Jacket Crack -

I've just started rebuilding what appeared to be a good '23 block to replace the tired engine in my '23 touring car. Yesterday my machinist discovered a fine crack in the water jacket area of this "new" block. It is in that "classic" spot on the lower left hand side.

I've seen lots of posts and articles in the club magazines over the years about this issue, but I have it admit that I did not pay enough attention. I just did search of this Forum and didn't find too much information.

My questions are: 1. Do you think this is a serious crack? 2. Do you think it will get bigger? 3. If you were rebuilding this block, what repair would you undertake, if any?

Here are some pictures: For what it's worth, the block currently in the car (last rebuilt in 1990) has an even bigger crack, which I fixed years ago with a slathering of J.B. Weld. It's still holding, but I always felt it was kind of a "cheat" repair. But maybe not!

I am aware of the "dangers" of Lock-N-Stitch in this area. The Babbitt is good on this block, by the way, which is why I don't want to discard it.

I look forward to your suggestions. Many thanks for your kind attention.

Sincerely,

Rick Benjamin
Lewisburg, PA

Rick_Benjamin wrote: ↑

Fri Feb 09, 2024 9:47 pm

Greetings Everyone:

RE: Water Jacket Crack -

My questions are: 1. Do you think this is a serious crack? 2. Do you think it will get bigger? 3. If you were rebuilding this block, what repair would you undertake, if any?

I look forward to your suggestions. Many thanks for your kind attention.

Sincerely,

Rick Benjamin
Lewisburg, PA

1. No.
2. No.
3. I might try applying some "weeping" LocTite, type 290, https://www.walmart.com/ip/Loctite-290- ... 010506fee7 . Or, if it does weep a bit, it will probably seal itself off. I have pretty much the same crack in my '21 Runabout. It's never left a drop on the pavement and I've never done a thing to seal it.

Thanks Jerry!

Hi Rich,
I used a 1/8" ball rotary bur to open up the crack so it could be filled with J B Weld instead of just spread over it. I also made a deeper
impression @ the ends (almost but not threw ) to deter further cracking. You can drill all the way threw but I tried a deep impression and
it seems to have worked well for the last 4 years & the engine has been real hot several times. I also J B Welded a aluminum plate over the
cracks. Craig.

I use High Temp J B Weld, on this common crack you have and on radiator repairs. You need to wait 24 before adding water, once dry is sand able
J-B Weld
37901 ExtremeHeat High Temperature Resistant Metallic Paste
Also:
J-B Weld
High Heat Epoxy Syringe, Dark Grey

That crack is a typical "hard water crack". Very common in engines that were found in the northern states. It was caused by ice or hard water.

Another thing you might try is a coat of red glyptal resin on the inside of the block, just over the area where the crack is.

I have a 1926 Franklin automobile, which has a cast aluminum crankcase, and cast aluminum transmission housing. Both were completely sprayed on the inside surfaces, after machining, with a coating of red glyptal, to seal up the numerous porosities that resulted in annoying oil leaks and seeps, and complaints by Franklin customers. This was standard practice at the Franklin factory.

The area should be cleaned with an aggressive solvent, such as MEK. You want to remove EVERY trace of oil or grease in the area of the crack.
Then mask the area off and apply a couple of coats of red glyptal to it. You can spray it or brush it on. This gets sprayed on the INSIDE of the crankcase. You shouldn't even see it on the outside.

Red Glyptal is available at electric motor repair shops, or places that supply electrical goods. You should be able to find it in a small bottle of perhaps 4-6 ozs, which is plenty for what you need it for. Thin it with MEK if you are going to spray it. Wear a mask, as between the MEK solvent and the glyptal solvent, it is a pretty potent and nasty material. Give it a couple of coats, and let it dry for a day between applications.

Once glyptal sets, it is impervious to oils and most solvents, although MEK will wipe it off. The coatings on my Franklin transmission and engine cases are still in perfect condition after 98 years, but I will recoat them before I do final assembly, just to be sure to cure any tiny oil staining. (I don't want people asking me if it's a Model T. It's already bad enough they ask me if I'm the original owner!)

When I visited the restoration shops at the Merle Norman auto collection in Sylmar a few years ago. they had a Mercedes 540K they were restoring, and the engine was apart on a bench, and I noticed that Mercedes also used glyptal on the inside of their cast aluminum crankcases and transmission cases. I assume this was a standard practice at any auto plant that used cast aluminum crankcases or transmission housings.

Permatex makes a great epoxy.

Several years ago I tried JB Weld on my '12 block but after some time it started leaking again I feel because the JB cures hard and does not flex with the heating cycles.

I grooved out the JB and applied a smooth coat of Ultra Black the applied a thin piece of shim stock over the crack with another smooth layer of Ultra Black covering the patch. A coat of paint and you have to look very hard to see it. The Ultra Black adheres very well and it's flexible and has been my permanent fix now for many years and miles.

Another success story for Ultra Black!

If you get a cup of water and dampen your finger and after applying the epoxy putty, whether JB Weld or Steel Devcon, if you gently tap down and smooth the epoxy putty with your dampened finger, you can make the repair glass smooth, which will eliminate the need for sanding. Jim Patrick

Research Belzona Epoxy - costly but effective.

Solder the crack with engine bearing babbitt.

Hi Ed,
I would like to know the details of how that's done. Flux used, how hot you need the block to be & how to cool without cracking. Can it be done without destroying the Babbitt in the block? I have also wondered if the material used in the wire connectors that " solder "with a lighter could
be used I imagine it melts @ 300 to 400 degrees?
Craig.

Here's a block that had been soldered up - never got the weeping to cease !

If it were mine, I would look for another block and examine it VERY carefully, maybe even having it magnafluxed. Do this before spending a lot of money rebuilding your engine. If you can't find one, then research previous posts about "Stiching" the block I have not done it personally, so have no experience. They drilled and tapped the block at each end of the crack and threded in a bolt. Cut off the head of the bolt flush with the repair and then drilled in a location which was part way across the first bolt and repeated the process all the way across the crack. I would not attach aluminum because it expands at a different rate from steel and would eventually come loose. Maybe put a thin layer of JB or heat resistant silacone seal over the completed stitch.
Norm

Rick:
i have mentioned this before regarding freeze cracks in a non-structural area of the block ... a weeping type weld porosity filler will usually seal quite well if the crack is clean ... i have used a shop vacuum to help with the flow of the sealer ... with the head inplace and the lower water inlet blocked you can hook a shop vacuum to the upper water outlet and apply vacuum ... the sealer is sucked into the crack ... i have used super glue for this also ... i clean the crack with a household detergent while under vacuum ... dry the area and then apply the sealer ( under vacuum ) ...do not use a flammable material to clean while using the vac to avoid an explosion from ignition of the vapors in the vacuum ...gene french

There was a how in one of the Ford Owner and Dealer magazines on soldering cracks with lead. I have done it a few times with success.
I also have used lock n stitch too. Most blocks are too thin there due to core shift.

Too Hugh Jass is not still around to tell us how they would fix that with MBRT.

I drilled holes in the ends of the cracks. Used an air file to groove the block. Used Belzona which as someone else just mentioned is expensive. It is a 2 part mixed molecular metal as Belzona would advertise it. My babbit was good too. Belzona dries very hard. You have to file it smooth as sand paper won't work. I used it in the paper mills to make emergency repairs to pumps and steam valves. I have a thousand miles on that engine now since everything rebuilt except babbit in mains and rods. It had plenty of shims to get a thou and a half tolerance.

A '23 block is a pretty low value item. If you have not done a pile of machine work on the block already, find a different block. Always start a rebuild with magnafluxing the valve seats, the main webs and the water jacket all the way around before proceeding further.

Everyone has their own acceptance and rejection criteria, which of course is fine. I would not hesitate to use that block after treating as Gene French suggested.

Here's another option which I think is the correct solution and permanent repair. I do this in my shop. Have someone who uses lock-n-stich products and finish with Irontite ceramic block sealer which is applied by circulating the block with a plate on the top and the solution flows at about 180 degrees and puts a ceramic coating and seals the water passages and stops any further rusting.