Well, I finally found a way to get a larger radiator in my SQ2000 cowling.  I need to inquire of the group, and also to Rusty, whom I know had a custom radiator made.  Since I am installing an aluminum catch tank well above the engine, am I correct in assuming that I can just have the radiator made without any expansion tanks on the radiator?  I would like to get as large a square area as possible filled with cooling fins instead of expansion tanks.  I've just printed all the recent posts regarding coolant tanks versus recovery tanks....I will read them tonight.  Thanks in advance for your input.  Paul Conner.

P.S.   my radiator will now be 16 x 10 x 4 1/2 inches. 

All the tanks at the ends of the radiator need to do allow the coolant to spread out across the end of the core without a pressure drop; i.e.; have all the core tubes see the same pressure.  Can’t really quantify it for you, but the tank x-sectional area should probably be 2.5 – 3.5 times the inlet tube area for “typical” radiator width, but could taper toward the ends if that helps.  If you’re getting custom built rads your vendor can give you guidelines.

Al