The air conditioning stuff is pressure rated much higher than is the heater stuff by about 100 PSI. It is aluminum rather than brass and copper. So, the aluminum is a bit better at dumping heat. So, the aluminum piece could be smaller than the brass and perform as well. There are hundreds of shapes and sizes of both, so there is an exact shape for your needs out there. Find out what car used the shape you want. Pull one at a You Pick It yard. Make sure there is still pressure in the system you open. Freon systems can hold pressure for years. Warm up the radiator to drain out as much oil as is possible. Have a really good welder TIG on some AN fittings to suit your system. I wrap the piece in a big wet towel or submerge all but the weld area in water. Piece of cake. Or send it to Tech Welding to build a custom piece from scratch.

 

The racer uses 3 , 44row Setrab coolers. Just enough to hold 160 degrees at full tilt. About 250 HP. A bit more than 1/3 of all engine cooling is done through the oil. You can watch the oil temp go up and down with the throttle setting. In 1980 our first rotary powered RX-2 had one big GM evap core and worked fine, but that first engine probably had less than 150 HP.

 

Lynn E. Hanover

  

 

In a message dated 5/29/2017 6:57:15 P.M. Eastern Daylight Time, flyrotary@lancaironline.net writes:

Ok thanks Lynn ... but is there anything to be gained from switching to an evaporator core Vs a heater core in terms of performance or durability?

Jeff