lsintampa

1975 Coupe....

So, I've been chasing a stupid fan / shroud fitment issue for about a year.

I've been running without the shroud extension since I got the car - because if I were to add the extension, the fan would for sure hit it.

SOOO, I've tried adjusting this and that. Checked the surround, added shims to lift the support a wee bit, checked motor mounts, transmission mounts... no matter what there was no way that extension would not come in contact with the fan.

Then POOF, dummy me. The car had a Z28 motor put in it by some PO. It came from a 1980 Camaro.

Well the 1975 Corvette fan is 17.5" diameter... and (wait for it), the 1980 Camaro fan is 18"... just enough to not fit.

So that being the case, I need a 17 - 17.5" replacement fan. I have a thermal clutch and I want to stay with that, but most fans I've found have RPM limits of 4K to 5K.

I don't want to go electric.

Question is with a clutch fan - and RPM limits of 4 to 5 K, will the fan ever see those RPM's?

If so, and if that is an issue can someone please point me to a good replacement fan?

Thanks,

Len

fede

Why is that? I'm in the process of restoring my 75 too and after reading a bit it seems that electric saves a lot of HPs. I'm going that route although I haven't settle on which electric fan to use yet.

drwet

Fan blades are readily available through the usual suppliers.

NeverTooOld

The fan clutches limit the fan speed to around 2500 rpm so any of the aftermarket 6 blade fans will be okay.

DUB

Glad that you found the 'problem' and know what you need to get.

As stated...either getting a new fan clutch and also a fan blade will do the trick. I just 'Googled' it and I saw something on fleabay for sale.

The reason I mentioned about the fan clutch possibly being replaced is due to the center hole of the fan you get may not be correct to that of your current fan clutch...because not all fan clutches are all the same.

YES... the electric fan can save some horsepower...but I seriously doubt that anyone would ever feels it in the seat of their pants by just doing a fan conversion and that savings in horsepower is more of an additional benefit to those cars that are having a cooling issue and need to have more air going across the radiator.

But like it has also been mentioned...a cooling system... if properly set up on a stock engine will do just fine with a clutch fan.

DUB

derekderek

so cut the blades down 1/4 to a half inch each.

corvetero

Hi Fede, I don't know where in Spain are you exactly located at - BTW I'm from Extremadura- but if you have hot summers in your area be careful about what combo Radiator-Electric fan you go with.

I have been using the Ford Focus mk2 dual fans with a 4 row brass radiator here in Texas and I can tell that those fans work pretty well, and you can get them in Spain quite easily.

I'm replacing the brass radiator with a 2 row Aluminum one, and I have decided to go with Focus fans again.

7T1vette

I would find an 'uncut' fan to fit it. Fans are balanced; even at 2500-3000 rpm, an out-of-balance condition will cause a considerable vibration. "Guessing" at the amount of metal cut of the ends of fan blades is just not the thing to do. (Unless your uncle is named Bubba...)

When properly assembled, about 2/3's of the fan should stick inside the shroud, with about 1/3 of it out of the shroud. And the ends of the fan blades should be between 1/2 and 3/4 inch away from the surrounding shroud. Less than that and the fan will likely hit when going over big bumps; more than that and the fan will be inefficient.

fede

Thanks for the tip corvetero. The car is getting restored in La Coruña but I will eventually take it to Barcelona. Probably won't drive it in insanely hot days but it will see days of 30+ degrees for sure.

I'm not sure what radiator it has, will check tomorrow.

lsintampa

This is what feedback I was seeking. Thanks!

lsintampa

lsintampa

DUB

Definitely a part I would not alter.

DUB