Stuck in traffic 340 got up to 220

[512Stroker]

Well I just got my 17" Derale fan. There's is no way this thing is coming apart and it should blow pretty well in the shroud. If they think it's too small or whatever we'll get something better

View attachment 1715769750

You will never know until you try it.
Does it have a cfm rating?

 

[Richie]

You will never know until you try it.
Does it have a cfm rating?

Couldn't find a cfm rating for it anywhere.
https://www.etrailer.com/Radiator-Fans/Derale/D17317.html

 

[512Stroker]

Couldn't find a cfm rating for it anywhere.
https://www.etrailer.com/Radiator-Fans/Derale/D17317.html

Try the Derale site
You need about a 3000 cfm to make it work

 

[RustyRatRod]

Try the Derale site
You need about a 3000 cfm to make it work

Isn't CFM with a belt driven fan RPM dependent? I've actually never seen one rated, to tell you the truth. I guess some are, but I've never noticed. It would have to be XXXX CFM @ XXXX RPM, wouldn't you think?

 

[Richie]

Try the Derale site
You need about a 3000 cfm to make it work

I've got a dumb question. How do they rate a non electric fan that is hooked up to your engine? It would be spinning at different rpms constantly.

Unless they all rate them at a certain rpm?

 

[Bewy]

You cannot judge the airflow just from pitch. Some years ago I made a rudimentary test rig to test a heap of mechanical fans I had lying around. My GTO came with factory A/C, 19.5", 7 blade, clutch fan. The blades 'looked' like they would pull a lot of air & had a lot of pitch. It did quite poorly & an 18" plastic fan used on local Fords outperformed it. The best fan was a 7 blade Mopar fan that was over 20" in diam, do not know what model it came off. I trimmed the blade tips so that it would fit my GTO shroud, & it has been doing a great job of keeping the engine cool for over 15 yrs.

 

[512Stroker]

I've got a dumb question. How do they rate a non electric fan that is hooked up to your engine? It would be spinning at different rpms constantly.

Unless they all rate them at a certain rpm?

You answered your own question.

 

[512Stroker]

Isn't CFM with a belt driven fan RPM dependent? I've actually never seen one rated, to tell you the truth. I guess some are, but I've never noticed. It would have to be XXXX CFM @ XXXX RPM, wouldn't you think?

All fans have a cfm rating, that number may not be widely available, but rest assured the engineering team that developed the fan did so using SAE standard's or their own industries methods.
And yes there are done a constant rpm.