Posted for "Tracy Crook" <lors01@msn.com>:

I still like the idea of an oil-water heat exchanger.   I'd go with either option 2 or 4.  What I want is an exchanger with enough sq in to get the oil within 2-5 degrees of the rad inlet temp.  This would require MANY sq inches and probably would not fit in the end tank.

I love my Henrob torch (especially on stainless) but I've never gotten good results on aluminum.  Tracy