Quote Originally Posted by Systemlord View Post
Martinm210 I have been meaning to ask you something about the SR1 560 140mm radiators, does the extra 2 rows of tubes increase flow more than having a thick radiator with taller tubes? I remember a review where you stated the radiators being thicker had more tubing volume (also lower pressure drop) because of that extra thickness. I remember 25 years ago in Oregon riding Honda 125's racing bikes, boy was that fun!
Probably, I think it really comes down to the tube size and how many you have. It also probably depends on the entrance loss a bit. I believe they use a flaring tool when constructing these radiators to sort of open up the ends of the tubes and some flare the ends a bit more than others which can only help in reducing restriction.

Tube length is a bit of a mystery to me though. You would think radiators with longer tubes and the same number/size would be more restrictive, but according to some tests the quad radiators have actually tested lower than the short. It perhaps has something to do with turbulence I suppose but I'm not sure.