Welding ?
 

The bolt holes on the right side of my block are broken. The metal has actually seperated , so I am going to weld in two threaded rods and I want the stongest weld as possible. I have the option of using a 80 amp flex core wire welder or a 70 amp arc welder. Which would provide the strongest weld? The two bolt holes I am refering to are the ones that sit over the water passage.

I could be wrong, but I think the arc weilder is stronger. Use 7018 rod, it's easy to use, and it's a tough rod.

Man if you have never welded cast iron then you are in for a rude experience. I would do some research on it before I tried it. Ask around your local area and you will not find many people at all that have the ability to weld cast iron correctly.

Ditto what Technick said. Welding cast iorn iron is not easy to do correctly. If it was me, (and I am modertely profeicient with a stick welder) I would have a welding shop do the work. But that's just me.

welding " NO! "
 

I have been welding for 15 yeras now. If you were to weld on too your block the first thing you would nead is a heli-arc welder. Don't even try with a mig or stick. You will get to much heat. Get the tig welder and try to weld it. You should be able to get the metal to stick to each other. But the problems lie's with the strangth of your weld. And that is part of your ? The weld strangth will be about as strong as your grandmother tighting lug nuts with a small wrench.The first bump you hit it will break. I would not weld it. Try a heli-torq. Drill and Tap. but dont weld it

I agree with all the above posts, but for me if a block is broken in my mind it usually means that is is time for a new one or at least a different one that isn't broken. Even though I know it is very hard to find the correct block with the corect codes that match. If this is of concern I have a suggestion. Carfully remove the date codes from the original block and obtain a different block. Grind down or have a machine shop machine down the codes on the new block and the back side of the old codes (don't get too thin). Either JB weld the two together or use an other method for attaching it like welding if you prefer. Even though the original block is now in the middle of irriversable sergery :( at least this way the block is structuraly sound.:cool:

To do proper cast iron block or head repair you need a mig and a large oven the first thing you need to do is slowly heat up the block to above 500°F then do your weld making sure you block heat stays above 400° if it drops down then you need to heat it back up before continuing when all that is done stick it back in the oven at around 300° for a couple of hrs until it stabilizes at that temp then set the oven down to about 200° then 100° at each step of the cool down you want the block to stabilize at that temperature before you set the oven to the next colder step. after all that is done you will need to check for trueness on your mains, cam bearing and bore. It is not really an easy or cheap proposition.