I'm working on a 23 T for a friend and it has a couple cracks on the block on the underside of the water jacket on either side of the water inlet port. It's my understanding that this is a common area for cracks. I've considered a few different approaches and would like some guidance on which would be best. I would like to make the repair with the engine in the car.
1. Drill the ends of the cracks and braise them
2. Drill the ends of the cracks and use cast iron welding rod and weld them up
3. Heat area with torch and use lead to seal the cracks, tapping it in with a small hammer as it cools.
4. Install the head and gasket then seal the water inlet port off. Use a vacuum on the water outlet to pull a suction on the water jacket then apply epoxy, JB Weld or silicone RTV to the cracks and let the vacuum pull it into the cracks.
I'll chime in on one of the methods you listed. JB Weld won't hold unless you use a lot. I tried it on a block with a crack like yours.
Even with good cleaning, Ving it out, drilling the ends, and applying window screen for reinforcement, it soon broke loose and leaked. On a water pump, I Ved it out to 3/8" and it worked fine with screen. You wouldn't V out a block that much so I would avoid JB Weld.
There is a place in Turlock, CA that offers products to seal cracks, Lock N Stitch I believe. Only problem is you need enough thickness to hold three full threads of the screws. Typically the area you have rusts out thinner than that.
Other than that I've heard that brazed repairs continue to leak but that could be remedied by Bars Leak I suppose. I've also heard that a solder repair works because you aren't using enough heat to crack the block. I'd certainly steer clear of welding.
I have a block that has a slow weep. I'm considering this product http://www.belzona.com/en/products/1000/1111.aspx for the repair. No heat involved. The lock and stitch method http://www.locknstitch.com/Default.htm has been recommended to me, but there isn't a defined crack in my case, at least not one that is visible.
Found this old post by Stan Howe. You might want to PM him. Good luck!
By Stan Howe Helena, Montana on Tuesday, October 08, 2013 - 11:00 am:
This showed up in my mail today from Farm Collector magazine. Perry Matthews was the Vo Tech Shop Foreman/teacher here for many years and was a Model T guru for many. He did a lot of T engines and babbitt work. I barely knew him as I moved here only a couple years before he died. I was surprised to see his name in this article. If it could be done, Perry could do it according to all I have heard about him.
Interesting idea and worth trying.
After reading about different methods of welding cast iron, I thought you could use one more that worked for me and others. Most restorers of old-iron have the necessary tools to perform this operation.
My dear departed friend, Perry Mathrew of Helena, Montana, showed me this trick.
The crack we fixed was along the bottom of the water jacket on a 1926 Model 'T' Ford that I own. We performed it over 20 years ago and it hasn't leaked a drop.
Small 1/8 inch holes were drilled at the ends of the crack. This crack was over 10 inches long. Then using a rotary file, the crack was 'V'd out but not all the way through the crack.
Using an acetylene torch, with a small tip, he played the heat on the crack while at the same time he would rub the crack with a piece of small copper tubing. You could see the crack was getting a copper color to it. Very little heat was used, just enough so a copper tone was showing in the 'V'd sides of the crack.
Next he took some solder and used just enough heat along the crack to melt the solder. After testing the job for leaks, the solder was filed down to the contour of the block. We applied paint and the crack is hard to find.
I keep antifreeze in the 'T' year around with no loss of coolant.
I have no idea of the chemistry between the copper and cast iron. All I know is it works.
Chester : I have good results with J_B Weld. After 4 years no problem
Here is a past thread were many methods are discussed and several photos of successful repairs:
I am curious, why would anyone want to repair a cracked block if it was not a very very very early block???
Here's how I fixed a 1910 block that had cracked and rusted through the water jacket. The previous owner didn't use anti freeze so the block was nearly ruined and the radiator was ruined:
What a neat idea to use a vacuum pump to pull the JB weld into the cracks!
Mark, I have used this method several times but, I use super glue first to seal the crack . After the seal dries, I pressurize the block and spray it with soapy water to make sure the patch works. Never had a failure and I have sealed Model A blocks inside the valve chamber.
What is the max temp a T block is likely to reach while in operation? "Belzona 1111", one of the above products, says it is good up to a temp of 392 degrees.
The engine in my TT was cracked there.It had JB weld rubbed on it and had been run that way.
I gave a 100 bucks for the engine in 1993 or 4 as the owner had points took off his car at a show because of the jb weld.
The jb weld has since fell off and there is no leaks.
The block rusted there and has never given any trouble.
I would check the 6 cylinder T thread recently started. I would say that brazeing would fix the leak if it is holding that engine together.
If you click on the two links you can see why we don't recommend anyone trying to braze or weld the castings"heads and blocks" unless they are well prepared experience and equipment.
You can see that the cracks come from the welded/repaired area.
We had to cut this area out and metal stitch it. No crazy glue or silly putty would of fixed these cracks.
We utilize this method as customers want a leak free engine coming back with no issues later on.
That's beautiful metal stitching...
My 1943 Farmall M was rolled and broken early in life. Some very large castings have been repaired by brazing, likely without disassembly of the tractor. Many cast iron repairs have been done in the past by brazing, likely because that was the only means they had to get it done.
Here is one that I brazed up last eve, The block will fit in a regular old oven, put it in the oven on 350 for about an hour, pull it out braze it up, take your chipping hammer to it, throw it back in the oven for another hour, shut the oven off and leave it in there over night. It works for me, I saw a block years ago all brazed up and figured it could be done so why not try on an old junk block first to see if it works and it did!
Looks good to me.
Crazy glue, silly putty and bubble gum.
What do they have in common? it will get you home but it doesn't last.
Here is a Seagrave block that was supposedly done at the Naval Yard well I could and did peel it off like dry bubble gum.
It caused the cast iron to crack on either side due to the amount of heat in one spot.
Would of been a simple repair with the stitch pins but ended up cutting and making pieces to repair the brazed stressed out areas.
Please look at the pictures and think twice before you damage you engines beyond repair.!