Ive got no ac in my car an oversized 4 core radiator correct fan shroud new clutch 180* thermostat and the radiator is sealed off to the core support. She generally runs cool unless sitting in traffic with ambient temps high 90s and humid. I do have a fairly decent built sbc that really likes to run hot afr is correct timing is good.
Looking at a set of Flex A Lite 295 dual fans 4600 cfm anyone else ever use these

 

Probably between 1/3rd and 1/2 of that at idle depending on your idle RPMs.
In many years of working as a technician, I've never seen a Chevrolet of any kind that was equipped with a mechanical fan and clutch that would overheat when the system was operating as designed. If it's overheating (ever), there's something that needs to be repaired to restore the system to proper operation.

As for "the distance it is from the radiator," that's irrelevant if the factory shroud is installed correctly and is undamaged. Actually, placing the fan further back, and having a tapered shroud pulls more air through the outer edges of the radiator core, and cools the entire core much more evenly than having the fan blades an inch or less from the core. That's absolutely true, and it's also true for electric fans, not just for the stock mechanical fan.

If it's "overheating in traffic", there's something wrong. Either the fan clutch is worn out and the fan isn't operating when it should be, or the shroud is damaged or not properly installed.

And as for "horsepower it robs," In hot weather, when first starting, there is a load as the fan spins up and draws a lot of air through the radiator. Once the thing is in cooler air, though, and the fan clutch disengages, there's not much HP lost/used by the mechanical fan. Again, this is on the assumption that the fan clutch is functioning as designed.

What killed mechanical fans the most for passenger cars was transverse mounted engines. You can't have a fan clutch and fan on a transverse engine. There's also a reliability issue which came up when warranty periods got much longer in the 2000s (fan clutches may not last for an entire 7 year/70,000 mile powertrain warranty).

Mechanical fans are still used today on many pickup trucks, and on some SUV's. Some SUV's with longintudinal mounted engines do use electric fans, but even some of those use a mechanical fan when they are equipped with a "tow package" for towing trailers.

 

I have not use them but they seem to be good as long as the shroud can fit easily and you do not run into clearance issues at the upper control arms.

The CFM's are really up there...which can not hurt and with it beign a variable speed....that is good also.

Price is just about like the SPAl set-up...which is good also.

DUB

 

c6 racer x as I agree to some extent as to what you say.
mind you nothing on my car is stock nor original. If it was stock I am sure I would not have any issues cooling even without the big 4 core radiator,
I think it may depend a bit on how the motor is built and gearing too as how the car reacts to cooling in traffic or the highway.
in my application that is the case.

 

I found a set locally for sale that I am going to try out price is less than half of new.

 

Sounds like good way to start.

DUB