A Question for Car Guys

[Chuck Jackson]

Has anyone ever done, or had luck with, MIG or TIG welding a crack in the block of a cast iron block engine. I am restoring a 1949 Packard 4 Door with a cast iron straight 8 engine. I would like to keep the original engine, but it has a crack in the block. It runs, but when it gets up to temp it leaks coolant from the crack. I have experience with arc and oxyacetylene welding, but have neither the money or expertise to own/use a Mig/Tig welder. I know both magnesium and titanium have real high melting points, hence my question if this is a viable repair or should I hunt for a comparable engine. Thanks.

Chuck

[Chuck Jackson]

Thanks Wade. I have investigated this and will probably use it. I just talked to a guy in town who said the TIG/MIG thing would work, but like the nickle fix stated on the website, the cast iron has a habit of cracking around the weld. Short of dropping @ 5K for a comparable engine (totally seized) and then rebuilding it, your solution will probably be the best. As the car won't be shown (changed the electrical system to 12 volt, alternator instead of generator, 4 wheel disk brakes, etc) nor driven more than 500-600 miles a year, I think this will last for my use. It really is a lovely car.

Chuck "who at 6'2" can lay on the back seat almost straight across"Jackson

[ken k]

please post some pix!

[The Big Ben]

This might be a repair that would be worth having done professionally. Cast iron can be tricky and even more so in a complicated casting such as an engine block. A welder with experience repairing a cast iron block can do amazing things.

[Chuck Jackson]

This might be a repair that would be worth having done professionally. Cast iron can be tricky and even more so in a complicated casting such as an engine block. A welder with experience repairing a cast iron block can do amazing things.

Indeed I will as I have neither the tools (I'm told a high oxygen input welder to heat up the cast iron hot enough to fill the crack after boring around it) nor the expertise (this is way out of my, my bother-in-law, and nephews league). I was just exploring as many options as possible.

I will be Upstate for a good portion of July and will post pictures. I have owned this and a 1941 Packard for 25 years and in the past two years have finally saved enough money to start my dream project. With FD, tubas are out, so the Packard is in. The 1941 is a total loss.

Chuck

[Tale_09]

Nice post.

[ghmerrill]

I have put a lot of time recently into issues pertaining to repairing cracks in cast iron. I can't speak from the perspective of practice, but I can at least pass on some of the concerns I encountered. In my case, this was oriented towards fixing a 'T'-shaped crack in an old cast iron bell I picked up at a local salvage yard.

Theoretically, welding should provide the ideal fix, and it appears that (theoretically) you can mig/tig weld it. However, the risk of screwing it up seems a bit high -- especially if you don't have extensive experience.

So far as I can see, perhaps the biggest problem with welding or brazing of cast iron isn't in the welding/brazing itself, but in cooling it afterwards. What I've seen is that the cast iron will tend to crack as it cools. The recommendations on how to avoid this generally recommend immersing the object totally in sand immediately after it is welded/brazed, and keeping it there for two or more days in order to severely retard the cooling process and avoid cracking.

With an engine block, it SEEMS to me (no experience!) that you MIGHT be able to get away with brazing it (even with a fairly high temp filler) since the block is so massive.

In my own case I have decided to chicken out and use another approach (which is likely to be greeted with hoots of derision): JB Weld. I KNOW this won't provide the quality repair of the bell (in terms of ringing it) that brazing would. But it totally lowers the risk of additional cracking. And the bell will be mostly a decoration anyway.

There are a number of testimonials about repairing engine blocks (and similar items) with JB Weld. Laugh all you like, but it does seem to work (even better if you mix in some additional powdered iron or steel). You might consider this approach. Drill each end of the crack (to inhibit the crack expanding), grind it out, and patch with JB Weld.

Just an idea. Others have done it.