Ford AC Retrofit

[bohica2xo]

The SD7H15 is 154.7 cc/rev But like any compressor, shaft speed matters:

https://www.sanden.com/objects/SD7H15_Performance.pdf

The York was 210 cc/rev. On a gasoline engine. Overdriven from the crank, on an engine with a cruising rpm above the diesel's redline.

75-79 F series trucks had big evaporators, but they are subject to inhaling trash. The air box design makes a heater core bypass valve necessary. Here is a decent thread on the heater core / evaporator assembly:
https://www.ford-trucks.com/forums/1125 ... th-ac.html

I don't know the specific needs of the Cummins you have regarding the heater / bypass circuit. Some engines need that flow in the cooling system, and you should use a 4 port bypass to make sure that flow is maintained if it is required

[Powerstrokinit]

I have no coolant flow through the heater core when the AC is on/heater off.