How much CFM to cool LS

[67CamaroLSX]

Working on 67 Camaro with 6.0 lq9, 4l80E and vintage air. The motor has some mods, should be around 450hp at the wheels. I have the Griffin ls radiator with there dual fans. After reading more about them I realized the fans are only rated at 870cfm each. The car is not on the road yet so i really don't know if this will be enough to cool it or not?

[Malubu795]

I'd want min double that... look into spal fans, they're $$$ I have couple 11" versions that pull ~1800cfm each.

[67CamaroLSX]

Thanks for reply. I wonder if there is a different way they test these fans. Griffin mentions true cfm? I dont know why they would put such small fans on there radiator.

[dhutton]

Why don’t you wait and see how it goes before replacing the fans? I would think the core design plays a heavy role and the question can’t be easily answered...

True CFM likely means in the application versus some free air testing. The specs are so nebulous that you can likely get widely varying test results...

Don

[GoodysGotaCuda]

Why don’t you wait and see how it goes before replacing the fans? I would think the core design plays a heavy role and the question can’t be easily answered...

True CFM likely means in the application versus some free air testing. The specs are so nebulous that you can likely get widely varying test results...

Don

I agree.

[67CamaroLSX]

Will do. I talked to griffin yesterday and they assured me it would cool my engine. They said it would cool 600hp to the wheels. I'm probably around 450hp to the wheels so it should be ok. They also recommended a 180 thermostat.

[csouth]

As others said I would wait. The other thing that comes into play is your radiator tubing. I chose the Griffin because they use 1.25" tubes, most others I've seen are only doing 1".

[andrewb70]

....They also recommended a 180 thermostat.

I would really love to know their logic for using a 180 thermostat. A stock one is 187 degrees.

Also, GM rates their OEM fans in watts. I am using a C6 Corvette fan in my Cougar and it is rated at 400 watts, so it draws about 32 amps. I would look at the amp rating for the fans that you have and if they are not rated to pull at least 15 amps, I would look for other options.

Andrew

[hifi875]

they are designed to run pretty warm anyway. mine runs 195-200 most of the time with stock thermostat. in my suburban the engine runs 210 all the time

[67CamaroLSX]

What temps do you have your fans to kick on at? I think mine kick on at 205 low and high speed @ 225.

[andrewb70]

What temps do you have your fans to kick on at? I think mine kick on at 205 low and high speed @ 225.

On a stock configuration, the fans kick on at 212 and shut off at 205. This is why most "normal" engine operating temperatures tend to be between 205 and 210. I have variable speed fan control on my Cougar and I start to ramp in the fan at 200. I rarely see temperature above 210, but I also have a hole in my hood, which helps to vent a lot of underhood heat. I also shut the fans off above 35 mph.

Andrew

[TheJDMan]

I agree wait to see what actually happens once you get the car running. But in general, I want the most cfm I can fit behind my radiator. I'm running a single flex-a-lite rated at 3300cfm and have no over heating issues even on days over 100deg out.

[qnitro]

I agree wait to see what actually happens once you get the car running. But in general, I want the most cfm I can fit behind my radiator. I'm running a single flex-a-lite rated at 3300cfm and have no over heating issues even on days over 100deg out.

Do you have a pic? can you text or put it here?? Trying to see that it looks like

[dhutton]

Do you have a pic? can you text or put it here?? Trying to see that it looks like

Hi Kevin. I am guessing this is it:

https://www.summitracing.com/parts/flx-188/overview/

Don

[qnitro]

Thanks Don, yeah wanted to see it actually in the car also..I'm gonna pull the trigger I think, want to know how it was mounted on the Radiator more than anything.


Hi Kevin. I am guessing this is it:

https://www.summitracing.com/parts/flx-188/overview/

Don