New Variable Speed/PWM Cooling Fan Controller from PSM

[OldTimer]

Right now there's a 180° EMP/Stewart in it. For the past several years, I had been running a 160° thermostat that the engine builder installed. That was with a v-belt setup and regular BBC shroud, fan, and 4 core radiator. The car never ran cooler than 170° and typically it ran between 170-185 on the highway regardless of air temp except in traffic where it would climb over 200 and dead still on a hot day in traffic it'd go to 220. Just for kicks, I tried the 160° thermostat and it stayed a little cooler longer but eventually creeped up to almost 200° and of course the fans kicked in. Driving on the highway was the same as with the 180 thermostat. No difference whatsoever. I do notice that if I get off the highway and putter around stop and go for a few minutes, it goes up to the 215-220, but the minute I hit highway speeds again it goes down to 200. So I know 200 isn't a bad temp for a BBC, its just nagging me wondering if the fan being on limits the amount of road air that can run thru the condenser/radiator. The radiator has a dozen flap openings as seen below:



The engineers at BeCool actually sent me a metal template as a guide for the flap pins and layout. There's about 1/4" of aluminum in the middle that I left in because I was concerned about the flaps getting sucked in by the fans. I think its just another (minor) restriction. I may pull out the shroud and cut those centers out of the top section and see what happens. If they _do_ get pulled in then I will weld in a 1/8" aluminum wire across the span to prevent that.



I calculated the amount of the opening relative to the overall 23" by 16" basic radiator core which is about 368 square inches. But two 12" openings equal about 226 square inches, then there's 24 additional openings which make for 37.5" square inches. So the total opening area right now is approximately 263.5 square inches. Eliminating the dividers would only give me just under 4 square inches which sounds useless, but in terms of air turbulence... maybe airflow would improve?





The inside depth of the shroud is about .9500" and I have taken the time to seal off all four sides against the radiator so there's little chance of the fans pulling in engine air. I also have a full width forward core support cover and a hood pad that seals pretty close.