Block crack - is this terminal

[Dave Mann]

I'm with metal stitching, a time proven repair, I had two cracked turbocharger gas entry castings repaired this way in 1979 and they are still in service. they were nearly as big as a chummy. Belzona is good stuff, as one ship repair manager said it would put they out of business. That was 30 years ago on a twin engine passenger ship, each engine was 8000 BHP in Southampton. One of the reduction gearbox main wheels was found to be loose on it's shaft in the West Indies, after cleaning it was secured by Belzona and found to still be secure in Southampton, so Lloyd's let continue in service.

[bob46320]

How do you solder cast iron ?

[Bob Culver]

Decades since I did it. Had no fancy tools. Would have cleaned the metal using a small grinding wheel in electric drill. Used a plumbers petrol iron with generous size bit. (In recent times have used large hand solder bit clamped to a propane gas torch). Woud have used Duzall flux. 50/50 radiator solder would be nice but probably used 60/40 plumbers solder assuming still available. For such a thin section the heat can be conveyed mainly from the bit, avoiding direct flame contact. Once tinned the solder can be built up in dabs. 
The ends of the cracks ideally identified and small screws fitted.
If you can make up and attach a cover a neoprene or cork gasket alone may suffice. A neat cover plate with countersunk screws would add character.

[Winston Teague]

If this is a standard touring engine, i would make up a suitable patch, and drill and tap water jacket 4 or 2 ba in a few places round the edge of the patch, and screw it on on a bed of epoxy/araldite/silicone. Not the answer for a customer's race engine, but what have you got to loose exactly? Held water on a cracked corner on a vintage Meadows block no prob for 20000 hard miles......W