Seems to me that the radiator could cause a big pressure drop. Have as big a
radiator volume as you can and as big a return line as possible- up to the 1
3/4 " that the  pump inlet is.

 I just ordered and am anxiously awaiting delivery of  a C&R Racing rad. It's
plenty big- 27 x 18 x ~2 1/4, with  AN 16 fittings.

As far as  friction loss, it goes up with the square of the volume of flow.
You can have a smaller radiator that drops the coolant temp less than a large
rad, and you then have to run the fluid through the system faster.  If on the
other hand, you use a bigger, more effective radiator, with the coolant
returning from the rad much cooler, it seems that you could run the coolant
through the engine much slower.

Just ruminating.

Brian Trubee

 
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