Can cast iron be welded

[geneo4116]

have a 72 chevy 350 engine,where the starter bolts the out side hole for the starter has been broke off about half way,still holds a bolt and starter,but i dont think the starter lines up corectly,or the shaking and vibrating get the starter out of whack and keeps chewing up starters,can this be welded and metal welded in there,what say you[S

 

[Unkl Ian]

There are specific rods for Arc welding cast iron.
I've done it, no problem.

But at the same time, it is real easy for someone to make
a mess, if they are using the wrong process or materials.

 

[rockabillyrat]

I like to weld cast with a torch. More of brazzing really. You need to grind the surface down and weld it on a neutral flame. They make rods just for cast.

 

[donsrods]

I think I've also heard it is important to preheat the area to be welded with a torch first, or is that something else?

Don

 

[Willowbilly3]

Do you still have the piece? If you can get at it, I would use a stick welder myself. I don't think preheat will be necessary, and even if it was you would be talking about heating the whole block.
This is a typical problem with that type of starter design. Chevy put a tail brace on to help fix the problem but they are a pita and most poeple don't put them back on. If you have a few threads left in the hole you can get a longer bolt, then trim it so it almost bottoms out in the hole so you can utilize all the remaining threads. I scabed one together for a guy once by carving a hardwood block to fit between the starter and the block and driving it in. He got by several years until he swappped engines.
The starter issue is just one of the reasons I am not a big fan of the small block Chevy. That and the crappy valve cover design with the sand cast sealing surface on the heads.

 

[CR55]

I had the same problem and took the car to a welding shop. The guy brazed a stud in place, but it was off just a hair and the starter made grinding noise and tore the teeth of the flywheel. I know you don't want to hear this, but I swapped blocks and had a shop drill and tap a center bolt in a mini starter. No more problems for the last 4 or 5 years! I can't remember the amount of starters. I have been through !... CR

 

[PA41]

I've used nickle rod on cast with suprizeingly good results for water jacket cracks. I'm not sure it's structurally sound--might just be a crack plug.

Worth trying though.

PA41

 

[geneo4116]

i dont have the piece that cracked off,but im chewing starters up,very frustrating,when you bolt starter up it works for a few days,then i think vibrating shaking moves starter off kelter and wala fubar again. can still get bolts in to grab some threads used longer bolts they are grabin,but i think the mounting surface of the out side hole is catywumbus not bolting up square,any ideas i can do my self at home,