Bill,
I am not Ed but in the "big links section" I found  www.durafix.com for the aluminum rods that use a standard blowtorch. I saw this stuff demonstrated at one of the big auto shows at Lowes Speedway and I was impressed.
The website has video so you can see it work.  Durafix is from South Carolina. The link section also lists a British Co. that seems to sell the same thing but the shipping would be more.  I was looking to order some this month so I had the info nearby,which meant I could give you a quick answer.
So, Bill 'ole buddy' I hope this is what you were looking for. 
                                               
                                                                      Pat Robinson

Hi Bill,

What suprises me is it also works on cast aluminum. The website shows a repair to a boat propeller that had a chunk broken off. They just built up material to fill the empty space and then went back & machined it to shape as if it was new material. I would think you could do the same on an engine.
I will be interested to hear about Ed's experience.  This stuff works at 732 degrees so I don't think engine temperature would degrade the material.

By the way, Bill I am going to PM you on a another topic.

                                                              Pat Robinson

Hi Ed,

I seem to remember you testing some aluminum brazing rods that were not to expensive nor hard to use.  Correct?  Seems it worked great for some engine case repairs.

If so, can you relist the information?

Thanks
Bill <><

Hi Bill

 have  tried these  many times  and  have  NEVER had  any sucess on any  cast case, The  rods  work great  on bar stock though, and  they work best  on  small or  thin pieces, larger pieces seem to have bonding, and of course if you get a model engine  too hot  you will  warp it

Randy

Scott Dinger at hyflow mufflers does great engine case repairs. He has a way of cooling the case and welding it back up. He did a Fox 59 for me that had one of the lug holes broken out. When I got it back you could hardly tell it was ever broken. Super job.