welding iron heads

i have repaired a damaged CJ head. intake port wall had a hole in it. I plugged and over welded the plug. I used Ni55 rod so expansion would be a little less and cracking less prone.

repair came out well. the head pressure tested to 80 psi fine.

my question is - will it last?

I have welded several cast car parts, axle housings and exhaust manifolds mainly. the axle housings I would cut off the bottom of the center section and plate over it for better ground clearance on off road trucks. they held up fine. never leaked and never broke. the exhaust manifolds would sometimes re-crack from the heat cycles. so this falls in between. the heat cycle on this area will not be very bad 50 deg F to 200 deg F tops.

so if the repair is good at start will it hold under heating and cooling?

anyone used a cast head with repairs before?
I know I can replace the head, but this is more about seeing if I can get it to live and keep it living. just curious on others success or failures.

chris

I've welded a lot of cast iron over the years even the main bearing saddle on a 4 bolt main 427 Chevy machine shop dropped it and they brought It to our shop they make a TIG rod for cast iron that works really good but I'd say the most important thing is how you prep what your welding and the Quality of the cast iron really old iron from the 40 like a flat head for V-8 I have went with brazing with brass rod real old iron from the 1800's you have a 50-50 shot seem like more sand than iron back to prep work I always use a burr on die grinder and clean and bevel Really good the try and keep heat down and when your done wrap with insulation in the early 80's we had a box with powder asbestos We called it the cancer box duh great stuff for slow cooling cast iron. As far as your weld job just look it over make sure you didn't get any spider cracks after its cooled off if you do weld cast with a crack you should stop drill it with 1/8" drill bit to keep it from cracking more

prep was as you said. burr ground and cleaned and beveled. I opened the hole up some to make certain all material i was welding was good.
welds were heavily peened with air hammer after each stich was laid.

repair cam out well and air tested to 80 psi.

i was just curious if i did my part right would the repair hold up to modest street use or fail due to heat cycles.

thank you for the reply.

The only type of fill which seems to last when welding cast iron is silicon bronze ... unless the base piece is heated cherry red and more cast iron is used for the fusion then normalized SLOWLY..

We use silicon bronze and sand to slow the cooling like said above. works fine.

From time to time we get castings that come though our shop that were factory repaired. It is not uncommon to see welding on the deck of Big Chevy heads, valve cover rails on small Chevy heads etc. I've seen it on the pan rail of a 460 block and recently on the side of a '68 Ford 302 block. It always looks like they use nickel rod and peen it as it is cooling. I wonder if the factory did any oven pre heating?

If you follow a good proceedure and heat treat/ stress relief the weld will last the life of the part.

I sure love using 889sp rods for cast. Its as easy as soldering, flows so smooth and machinable and doesnt warp stuff or crack easy like advertised!

What about welding on an iron trans case? I have a toploader that lost 2 mounting holes on the face to bell surface. Could they be welded back on with any expectation that they would hold on for a reasonable time?

SLord82 wrote:What about welding on an iron trans case? I have a toploader that lost 2 mounting holes on the face to bell surface. Could they be welded back on with any expectation that they would hold on for a reasonable time?

I have one that broke a driveshaft and broke all four ears off. It was when I was in High school My dad welded them back on with nickel rod and there still on there.

Ground a bevel on both the ears and the case. then bolted it down to an old bell housing. Welded a little on each ear at a time, keeping them cool enough almost to touch and slowly welded them completely up.

IDT-572 wrote:

SLord82 wrote:What about welding on an iron trans case? I have a toploader that lost 2 mounting holes on the face to bell surface. Could they be welded back on with any expectation that they would hold on for a reasonable time?

I have one that broke a driveshaft and broke all four ears off. It was when I was in High school My dad welded them back on with nickel rod and there still on there.

Ground a bevel on both the ears and the case. then bolted it down to an old bell housing. Welded a little on each ear at a time, keeping them cool enough almost to touch and slowly welded them completely up.

About what I figured. Just didn't know if it would stand up to any torque.

Thanks for the feedback!