Hi all. My clutch on my mechanical fan is shot.  Since the fan isn't that effective in 80+ degree weather anyway, I was going to replace it with an electric fan mounted directly on the radiator.  I have never installed an electric fan so I'm not sure exactly what CFM, physical fan size, and fan brand name I should use for my '76.

I have A/C, manual tranny, and my original 180 HP L-48 was rebuilt and bored 0.030 about 2 years ago.  I can't see the engine pushing more than 250 HP (just as a reference for sizing the fan.)  I'm also running a 160 degree thermostat and the engine rarely gets above about 175 unless the outside temp is over 80 degrees and I'm using the A/C.

Any suguestions? Fan size (both CFM and diameter)?, preferred brand?

Thanks in advance.

 

Diameter is going to be determined by mfg of the fan and space available.  The thickness of the fan can affect the diam.  Bottom line is use the largest most CFM fan you can find that will fit.  Our cars need all the cooling they can get.  With a properly functioning thermostat, you won't cause it to run too cool.   Some fans have a temp sensor that  measures the radiator temp.  This will operate the fan only when the coolant temp is up.

I know it not a complete answer.  I have not researched the various types and mfgs that will work on our cars.  Some of the other members have installed the electrics.  How about it guys, what did you use?

One more caution.  Make sure the alternator has enough capacity to handle the increased electrical load.

kstyer38622.8369444444

I don't run an elec fan my clutch seven blade works well enough for me not to change it, but I did some research and the Spal pulled the most CFM, you hear both pro and con on weather to run single or duel fans, I recomend to run a seperate power relay for the fan sensor and or switch.

check out Summit Racing.  They have a great selection on line and good prices.  The spal dual 11 in fans setup has a themostaticly controled switch and a manual over-ride switch.  They will fit nicely on the back of a C3 radiator and leave room for the frame brace the VB&P sells.

I use a flex fan & a 16" spal puller that I control manually when I'm in traffic. Also installed 2 7" spals behind the frt tires on the frame & run these almost all the time...they really pull the heat out of the engine compartment as a BB creates alot of heat.  A 7 blade clutch fan works just as good as the flex.  If I was going to electric only I would go with dual 11" Spal puller fans & an Alum radiator. I'd also put in an 180 degree thermostat in ..your car will probably run better. Running to cool or to hot are both not good.

Alan

I was at Summit Racing the other night and did see their assortment of electric fans.  I wanted to get the opinion of this forum before seeing what Summit had to say.  My experience is that Corvettes are "different" from any other car, and I wanted to see what has been proven on other Corvettes. 

My clutch fan worked great until I had to rebuild the motor, and it's not like I built up the motor (0.030 over, and a slightly more than stock cam, that was it), but it generated more heat.  That's one reason I put the 160 degree thermostat in it, so the engine started cooling as soon as possible.  I've never had any noticable performace issues with this size thero, but if I can get reliable and efficient cooling from the electric fans, I will probably put a 180 degree back in it.  I would like to have the fans controlled by a seperate relay and temperature switch, and possibly a manual override for heavy traffic.

How and where exactly did you mount fans to evacuate the engine compartment heat?

 

Thanks for all your comments by the way, these forums are a life (and money) saver!

I installed the 7" spal fans right behind the front tires on the frame laying flat pulling the heat out from the bottom. I think these fans pull 700CFM ea. & on a warm day the air coming out of those fans is really hot. It helps in the passanger area getting all that hot air out. The corvette because of it's slanted radiator probably  looses  20%  efficency of the radiator. A front spoiler helps quite a bit to pull in cool air when you're moving & make sure all the air coming in from the front can only go throught the radiator. You might want to do what I did & install a 16" high vol spal...I believe it pulls 2600CFM & use it when you need to. Whichever way you decide ...definetly use a relay & a seperate circuit for tha frt fan or fans as they can draw alot of amps. 

Good luck

ALan

the 160 thermo as you know is fine during the summer the motor is going to run some where around 195 anyway,if you don't drive the car during the winter its still OK, but if you do, it should run at least 180, if not you might have engine wear issues, another way to get the temp down during the summer is run a 20-25 lb cap, run a 30-70 mix of antifreeze- water with a bottle of Prestone cooling system lube to make up for the loss of corrosion protection due to the 30% anti freeze mix, of coarse the cooling and heating system has to be in good condition to run the 25lb. cap.   anips38623.5400694444

I was thinking about that too, with the anti-freeze mix and the cap, but I still need to get air moving to help the A/C. 

I was on Flex-a-Lite's site earlier and it stated they don't recommend an electric fan as a primary cooling source for a 4 core radiator (which I have.)  Does anyone know of a reason for that? 

I wanted to eliminate the mechanical fan to free up more HP and to get more efficient cooling, but if the electrical fan can't help, then I may have to rethink my plan.  Maybe buy a small fan as a secondary form of cooling...

Thoughts?

Beats me,new cars run elec fans as a primary fan, if you mount a fan in front of the condenser and use it as a pusher it doesn't work as well if it was mounted on the back of the radiator as a puller, my thought on that is with all the stuff forward of the bulkhead in the way of the airflow its almost useless as a secondary fan, not sure what rubber bumper cars look like under the bumper where the air intake is but you might try making the air intakes larger, ign. timing also plays a large part on how cool your motor runs, a couple more degs. adv. over stock settings might not hurt.anips38623.976400463