Thanks everyone,
that was a very interesting read. I never had any idea an engine could be over cooled, and damage the possible result.

I always thought a big radiator was better, but it's obviously more complicated. It seems better to use the standard radiator and to stick on some excellent thermo fans so that the temperature never gets too low and when it gets hot, the fans take away the extra heat.

Also interesting that the temperature differential between the rad and the engine should not be more than 5 degrees or so..

Ultimately I need to find out:

if my thermostat is now broken or mismatched to my larger radiator (The radiator might take the temp below it's operating temperature?)

what the actual temperature is (if too low or not)

What the optimal temperature is for the CA18 (I heard it was 90 deg?)

The radiator is from a nissan R32 btw.

justin