The Stovebolt Site Forums The Shop Area Engine Shop braising block with brass

Have a 1951 chevy 1 ton with a 216 engine, but the water pan has an outside leak (so I am told), but have been given a few options: replace, braise with brass, or put the JB Weld back on it that was holding, until I started cleaning, and scraping. This is all new to me, as was a dream to have an old truck, but I'm the one repairing it trying to prove a point to my husband, as he was really mad when I bought it. Need all the help I can get!

Water pan, or oil pan? From the title, it looks like it's your block?

Usually, depending on the location and the extent of the hole(s) producing the leakage, the order of preference might be:

First choice: replace the pan (if it is an oil pan) - call local junk yard and post a Want Ad in the Swap Meet. This is the safest and surest solution.

Second choice: if the hole/leak is small and accessible, grind it out, clean it carefully, and use JB Weld. This is the cheapest and easiest solution. I have done this to a small leak in a 261 block - no leaks in 10 years.

Third choice: weld or braze (requires more skill, tools, and/or $$$)

Fourth choice: if it is only a water-leak in the external water-jacket of your block, and you can find someone with the equipment and the expertise: better than brass-brazing might be to grind/prep the metal and spray weld the crack in the cast iron. I recently had this done by a retired engine rebuilder. He told me that he could use this method to repair a 20" water-jacket-crack in the lower edge of 235 block that I also showed him.

hey new girl, welcome to the shop, we'll help ya straighten that guy out and you can make him really mad when you tell him he can't ride in it

as Tim asks, where exactly is the leak? need to elaborate a bit, no "water pan" so it's either the oil pan [leaking oil] or the block water jacket [leaking water] or the water pump [leaking water and replaceable]

Bill

Tim has got it right on the options. If it is the block cast iron welding is best left up to an expert and as we all know experts don't come cheap. On the plus side Chevrolet sixes are usually available for a reasonable price if you need a replacement engine they made multiple thousands of them.

Yes a cast iron block can be brazed with brass, but by someone that knows what they are doing.

I paid $600 to have a bare block prep'd, heated in an oven, then welded by an expert.

Pictures of the crack will help.

Welcome to the 'bolt

It is the water jacket that has very small leak, and like I said the JB Weld held for a long, until I messed with it. Thanks for all your help and information.

do a google search for a product called lock-n-stitch easy to do and better than welding. i have used it many times philip

jwhite -- Welcome to Stovebolt.com! I haven't checked, but have you checked in at our Welcome Centre? If not, please do -- and give us all the details about your project. And please post it in the DITY Gallery!

Keep the questions coming -- we have a good crew here who are very experienced and knowledgeable (except for me -- I have to be constantly reminded how to hold the hammer I use to fix everything) and will be glad to help you all through your project.

As the guys said, 216s and 235s are fairly plentiful and relatively cheap (sometimes even free!), so unless it's important to keep that particular engine, don't spend a lot of money repairing it.

Thanks again!
John

Welcome jwhite. I had to laugh cuz it's usually the guys in trouble with their wives. I was ok until I got the backhoe. That one was almost a dealbreaker...
Like John said, why mess with that broken 216? I'm no expert on the 6 cylinders but from what I gather by reading stuff here, most guys replace those motors with a 235. It's my understanding that bearing and oiling problems make the 216 a relic not worth messing with unless you are looking to restore to absolute original, "numbers matching" condition. Welding cast iron, while not impossible, is difficult. Cast iron has unique metalurgic properties that make welding it very tricky. I think you could find a rebuildable 235 for the cost. I wouldn't even do it if someone offered for free cuz, 1)It's still a 216. 2)What if the repair failed? And what if it failed far from home?...at night...in a snowstorm!

you don't have to be an expert to braze a block, thats the whole idea of using bronze as a filler metal. It is a low temp melting point metal. You might want to peen it a bit with a chipping hammer, but brazing doesn't add much stress to the base metal.
The hardest part is cleaning the base metal and running it in whatever position the block is setting in.

What about silver soldering the block? I have used it before but not on cast iron, would it work?

Joe

It would be almost impossible to make silver solder stick to cast iron. Brass works OK, as long as you get the metal CLEAN, which sometimes includes grinding the area around the crack smooth enough to get rid of the casting sand that's incorporated into the rough surface of the block. Preheating the area around the crack for a couple of inches on both sides of it will also keep the heat loss from preventing a good bond. A correct brazed repair should be smooth, with no areas or brass piled up on top without flowing smoothly toward the edges of the repair. it takea a LOT of talent to apply brass into a smooth, leakproof bead. I've only been doing it for 45 years, and I still screw up occasionally!
Jerry

Since people are still posting advice about high-cost, high-skill techniques for cast-iron repair, here is a technique (mentioned in my post, above) that has many advantages over more "traditional" techniques. I had this type of repair done on a relatively rare intake/exhaust manifold-assembly a few weeks ago. THe part was repaired after few hours of labor, and very little expendable-material, and a far simpler procedure than necessary for other techniques.

This technique has been around for about 40 years but never caught-on until recently: powder welding (flame spray welding) of cast metals

spray-weld repair of a GMC COE cast-iron carb heater

planed mating-surface of repaired part

It looked to me that this technique requires much less operator skills that other welding/brazing techniques.

As I mentioned above, the person who did the repair for me also inspected a 235 block with a 20+ inch crack along the bottom edge of the block (along the base of the water journal). He said that the crack in that location could be easily and reliably repaired. He also said that it would be cheaper to find a new block.

Interesting. I'd definately keep this in mind for future projects where rare and impossible to find items need repair...