[Floyd]

Since the whole world is following this thread, and all involved are big fans of ole timey engines and machinery, I have included a few more notes as to cast iron and its repair. First -Cast iron can be repaired ,even rewelded back to essentially new.
Second- There is no magic involved, no computer controlled machines, no special material needed and no equipment needed that you can not cobble up yourself.
What you do need is great gas welding skills and more importantly, knowledge of the metallurgy of high carbon content iron ,i.e. the cast irons. You will then know that grey iron can be welded and "white " iron can not be. It all has to do with dealing with the carbon in solution and the iron-carbon diagram.
Since there is so much vintage machinery out there that is irreplaceable, learning how to save it is our job. Practice this and get good at it and help others.
The repair options: 1) pinning, -stitching; 2) brazing; 3) welding.
Brazing is a great option for areas not in the combustion chambers , intakes, brackets not under great loads ,etc. Easier to do because of lower heat required, but will probably never be leak free. For cooling channels in blocks, heads etc brazing is usually followed by a ceramic based block sealer and you have a forever solution.
Brazing or welding requires preheating and post cooling done exactly right or the process will fail and usually makes the problem worse or much worse or even un-repairable.
The materials required: fire bricks to build an igloo to house the part in and thermal blankets; A heating source to bring the part up to temp (slowly) i.e. natural gas blow torch .
For brazing, an appropriate brazing rod and flux and ox-acetylene torch.
For welding, an ox-acetylene torch and genuine cast iron rod or pieces of grey cast iron you have cut up. Do not use speciality rods made with nickel etc. You must use the parent material for this operation. For flux, use good old fashion Borax.
You should have all the materials you need in your shop.
Following the directions is the hard part. Not following them is failure, maybe today or maybe six months later, but always a failure (it cracked).
Preheating- 1300 degrees F for welding, 900 degrees F for brazing. Preheat time depends on size of part. A few hours for a 10 pound part, 24 to 48 hours for regular engine block. Cooling time will be about the same. It must cool slowly!!!
Electric welding always results in failure.
Pics included are more of diesel engine heads that all have been rewelded and remachined and returned to service All are successful and ready for millions of miles on the road. Note that the cylinder heads have a fill puddle of weld so as to not create a small hot spot. Big torch flame and the pre-heated part is already at 1300 degrees!
This is the only process approved by Cat, Detroit Diesel and Cummins .