What CFM are the stock fans?

 

Enough to cool your car. Leave them alone.

 

I don't think I've ever seen a CFM rating from the manufacturer for the factory fans. I think their attitude in service is like that of Aaron.

Are you having a cooling issue, or just curious?

 

Be careful with CFM ratings for Cooling Fans.

Most of the time the environment and testing conditions are not Standardized...
There are too many variables in testing conditions with most of the Fan Manufacturers.

Roughly 20 Years ago I started Importing some particular Electric Fans From Italy...
Due to their Testing Standards and their overall Performance.

Some of their top tier Models were/ are very impressive!

About 4 Years later NASCAR made the use of these particular Electric Fans mandatory per their Rule Book.
At that point, the first few American Retailers for these Electric Fans finally appeared...
Then I no longer had to Import the Electric Fans myself.

And for the last 3 or more years now, Holley has had partial control over their American Company...
(NOT surprising, as Holley has been buying up Company after Company; just like Federal-Mogul did after the 2008 Financial Crisis).

That Company is Spal Electric Fans.
The ONLY Electric Fans that I have used for about the last 20 Years.

 

Where I have space to run one, mechanical fan with a clutch is the absolute way to go for good cooling. The same radiator core that came in a single electric fan 305 F-car that struggles to keep the car cool came in a 2500 powered 350 truck or van and kept the larger engine cool dragging 5,000+ lbs behind it. The difference is the mechanical fan on the truck moves much more airflow than the weak electric fan.

I have taken the factory clutch fan setup a few steps ahead in technology now on a couple of LS swaps and LS managed setups. The Trailblazers with the LM4 5.3L came with a thread on clutch that spins right on a L31 or Vortec truck LS based water pump. The code to run the EV Fan clutch already exists in the P59 Green/Blue LS controllers. With a PWM relay tied to the PCM the fan clutch is then PCM controlled and even has a RPM feedback signal. The fan is then controlled as needed for engine, transmission or a/c cooling needs as well as set to mostly freewheel at WOT for added power when accelerating or passing.

I have converted a couple of these cars to the earlier clutch fan setup. The stock radiator has no problem cooling a 400-500 HP small block with a/c with the stock clutch fan.

 

barely enough to cool..
120 degree ambient, with AC on, and sitting in traffic, nope, not enough to cool.

 

The stock dual cooling fans could be ok if they came on at the same time..... I dont know why GM made them turn on at different temps and what not. id wire them to make them come on at the same time. one fan wil lstay on constantly trying to keep temps "decent" and it will never cool down enough by itself...


The single fan isn't bad by itself considering there's no shroud... much better than the dual.

The LS fans IMO are the best you can get for a cheap price.

 

100 percent agree.

 

I was actually looking this up yesterday if you attached that dark green/white relay control wire to the grey relay control wire it would make both fans work if the auxiliary fan or the main fan is commanded on

 

I could add that for the duals, fan#1 kicks in around 220°F, ecm controlled and Fan#2 kicks in around 235°F (except when A/C is enable). So they seem to come on quite high IMO, but it's what GM had them at. You can have the ecm tuned to get fan#1 kick in early in conjunction with a 180°F stat and you can change the second fan switch (pax side) to get it to kick in early as well.

 

you must be in Arizona.... yep you are!!! Brutal in peak summer I would image.

 

I heard GM did that cause the hotter the motors run the better it is for the 80s emission standards?? Something like that.


My car came with the single fan, but I added dual LS fans I just ground the second fan to the PCM controlled fan so they activate at the same time

Works very well.

 

I bought a 96 trans am the other day to pull the t56 out of it. I just looked at the fan setup on it, I might pull that off too and put it on my gta. I already have dual fans but I don't like that it doesn't have a shroud.

 

The Lt1 fans are thicker than LS fans so they wont be as easy to retrofit, but it is possible. I used them on my V-6...the fit is a little more snug with these

 

will gen 4 V8 fans work?
do they mount to the radiator?
meaning, do i need 4th gen radiator and fan assembly?
i really dont wnat to use the stock 3rd gens, and or go to aftermarket, trying to keep it still stock looking

 

Yes

 

That was answered just above your post. LT and LS is 4th gen. So when someone says I used LS fans on mine they are referring to the later version of 4th gen. 93-97 LT ,98-02 LS

 

thanks so much for that. I wouldn't have known as i dont own, nor care about, 4th gens.
i