Years ago one of my Dad's big diesel engines had a crack in the block. He bought some special certanium alloy welding rods and his friend who was a welder sparked it up for him. Never had an issue with the repair.

I'll mention one other thing be sure to magnaflux to look for cracks. Drill out the end of any crack prior to repair to avoid chasing it and making it worse.

Good luck.

I was just going by the fact that the nickel cast welding rod is rated at 55,000 tensile strength, vs the brazing rod rated at 65,000

Yes brazing is acceptable, the repair on the skirt by the oil pan rail will most likely only fail if smacked by a connecting rod again but so would the rest of the block. But brazing that main bearing support would worry me, especially if a racing engine.

Fixed this block with Certanium rods. Not sure if they are still manufactured.

If the brazing rod has a higher strength than cast iron, why? I would think that it is the strongest part of the block. Just wondering why. Not trying to argue.

I’d like to purchase some of those rods, any ideas on where?

It would all depend on the brazing rod used for the repair. The Harris-Welco 017FC60 rod is 70% nickel and an excellent cast iron brazing rod. If the customer was sure the welder (brazer) used that rod it would be stronger than the cast iron and hold up well.

You can try Lawson https://www.lawsonproducts.com/Certanium/889-Cast-Iron-Stick-Rod-Electrode-532/P12006.lp There are other brands that are high nickel content. The certanium seem to flow real well, but pricey. Good deal on ebay for nickel rods https://www.ebay.com/itm/294318845754?hash=item4486c52f3a:g:GCEAAOSwxZRhDY2H

Yep, looked them up. A few have them forsale. Kinda wondering if these are what Muggy Weld is selling?

Ok I got a story for you. About 25 years ago I needed a Mega block repaired that had a small window and pan rail damaged.
I was told to go see Charlie in Middletown, NY. He was an older guy who did repairs on all kinds of engines and machinery.
He prepped the block and “cold welded” half inch at a time with nickel rods. He then ground smooth , dressed and stress relieved it with a hammer and punches...When he was finished you couldn’t see the repair.
The story was that in his youth he designed and built the machine that polished the lens/mirror on the Hubble telescope for NASA.

Anyone have experience with a block that the crack has gone into the lifter bore? How much thickness between water jacket and lifter bore oil galley on RB/hemi blocks?

Found this on a welding site - sounds like cold weld to me

“If you can find it, Certanium 889SP is magic for cast iron. It needs no preheat, is machinable, AC/DC, material doesn't have to be real clean, just a good V prep. Do little, skip, do a llittle more, skip, etc. If you can't hold your hand on it, quit till you can, and go back at it. You won't be disappointed.“

Sent an email to the company asking for a dealer close so I can buy and try some.