Hi all,  finally back from Colorado cabin building trip, made good progress, had some fun.

 

Will be watching to see how that Rad works out Earnest.  I have an identical looking one that I considered using as an oil cooler.  Just about the most efficient heat exchanger I ever saw but I was concerned about flow resistance so I opted for a Harrison type that has much less fin area but is all parallel flow.  I did no scientific study, just took a deep breath and blew through it.  It seemed to have at least twice the resistance as the Harrison so I chickened out.  Hope it works for you cause I may need more oil cooling than the Harrison will give.

 

Tracy  (tearing down the 20B to replace Hurley apex seals : (