Thread: Derale 12" Radiator Fans

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Sorry this post isn't a answer directly to your question.We have found on the swaps for V8's in Astro vans,it's hard to beat the 14" fan from a Crown Vic.You have to run a relay because it draws so much.

One thing the fan companies do not tell you is the static pressure drop of CFM once the fans are attached to the radiator. If you see a fan advertised at say 4000 CFM, yea it will pull 4000CFM if you hook it up and hold it over your head, but take and attach it to the radiator and now the static pressure drop happens,that really lowers CFM.
We did a test on a brand name fan advertising 4200CFM. After attaching it to the radiator and measuring CFM drop, it pulled 1100 CFM.
The best results for static pressure drop is the Spal fans. They advertise 2750CFM and after bolted to radiator, CFM dropped 400 to 2350.
A true pusher fan will work where a puller cant be used. But it must be a true pusher, not a puller with the blades turned and rewire the motor.