Radiator fan

[blue69runner]

Have a 383 with 3:55 gearing rear end. Any idea on size cooling fan to use non clutch type. It is a 69 roadrunner. It had a flex fan in it and want to put a steel fan on it. Any ideas would be appreciated. Stock Rad. Thank for the help. blue69runner

 

[Ranger16]

FSM calls for an 18" dia. 7 blade fan.
I'd also add a shroud.

 

[diesel_lv]

3.55 gears with no overdrive will turn higher rpms on the highway where the fan isn't needed as much. VERY noisy!! I'd go w a factory 18" 7 blade w fan clutch. But if you really want a direct drive fan, Flex a Lite has a good, steel 6 blade 18" direct drive fan and a 18" aluminum 7 blade flex fan that can both handle 6k rpm. But it will be very noisy inside the car while cruising.

 

[Tony Tee]

I watched cooling fans tested on a dyno on YouTube and I can't find the video now. But the composite / flex fan robbed 30 horsepower . Not sure how much for a fixed pitch steel fan uses but I'm guessing it's up there! I use a viscous clutch fan. It engages. Only when it gets hot. Just saying.....

 

[myk r sanchez]

Why don't you want to run a fan clutch?

 

[33 IMP]

I watched cooling fans tested on a dyno on YouTube and I can't find the video now. But the composite / flex fan robbed 30 horsepower . Not sure how much for a fixed pitch steel fan uses but I'm guessing it's up there! I use a viscous clutch fan. It engages. Only when it gets hot. Just saying.....

That was an engine masters video, and i thought it was excellent, tho some criticized their methods. The video is long gone, cause m/t wants you to pay for them now, all there are on you tube now is teasers. IF my memory is right, the clutch fan cost around ten, there was a second that was worse, maybe an aluminum flex. The plastic flex cost 25, the solid steel 7 blade cost thirty.
Im using the plastic flex on my bracket car, and giving up the power for cooling. I used to cme back from a run at 210-220, now i come back at 175-180. Cools down in a quarter of the time.

 

[blue69runner]

Why don't you want to run a fan clutch?

Just from the past had one that the clutch did not work and car got hot. Had one on a 440 motor and it let go and went through the rad. So I know they take horse power away but I am not racing. If I don't like it then will go to a clutch. Thanks. Got and 18 inch fan coming form summit. Appreciate the help guy's and the your knowledge on this. bule69runner.