Stock 7 blade fan hitting shroud

Bolt · Jan 22, 2019

Stock 7 Blade Fan Hitting

I just replaced an old 6 blade 17" fan with a original refinished 18" 7 Blade. The 17" fan had a 1/2" spacer which I used on the 18" fan as well. now the 18" fan is hitting the shroud just on the passenger side. (Ron Davis radiator with full circle shroud). Without the spacer the fan is hitting on the bottom pulley. Any ideas? I cant find a 1/4" spacer.

Bolt · Jan 22, 2019

Stock 7 Blade Fan Hitting
I just replaced an old 6 blade 17" fan with a original refinished 18" 7 Blade. The 17" fan had a 1/2" spacer which I used on the 18" fan as well. now the 18" fan is hitting the shroud just on the passenger side. (Ron Davis radiator with full circle shroud). Without the spacer the fan is hitting on the bottom pulley. Any ideas? I cant find a 1/4" spacer.

Doyle · Jan 22, 2019

Shift engine to drivers side or transfer case to passenger side, all mounts have a little play.

Bolt · Jan 22, 2019

the fan clears of the inner circle of the shroud on all sides, just hitting the a reinforcing flat plate as the fan is too far forward....

blubuckaroo · Jan 22, 2019

Three groove pulley?
That gives very little room to play with.
On my steel shroud, I had to cut out the reinforcement to make it fit.
I also put the fan spacer on a lathe and cut it down so the fan would just clear the pulley.

tirewater · Jan 22, 2019

Use washers to make up that 1/4"?

I wish Ford (or anyone) had made a split fan shroud - it would make removing/installing fans so much easier.

My six blade fan had a shallow pitch compared to the factory seven blade fan that I replaced it with. I had a 3 groove crank pulley (for older AC install) that the seven blade fan would hit. Ultimately I ended up finding a 2 groove (stock) pulley that allowed me to use the seven blade fan.

Can you clearance (cut) the fan shroud?

Slowleak · Jan 22, 2019

Ace Hardware has a good selection of bolt spacers. I got some nice wide 1/4 inch ones to offset my A/C compressor.....

Bronco Junkie · Jan 22, 2019

I was under the impression that there were different sized spacers for the fan?

bronconut73 · Jan 22, 2019

tirewater said:
Use washers to make up that 1/4"?

I wish Ford (or anyone) had made a split fan shroud - it would make removing/installing fans so much easier.

My six blade fan had a shallow pitch compared to the factory seven blade fan that I replaced it with. I had a 3 groove crank pulley (for older AC install) that the seven blade fan would hit. Ultimately I ended up finding a 2 groove (stock) pulley that allowed me to use the seven blade fan.

Can you clearance (cut) the fan shroud?

Moroso makes fan spacer discs of varying thicknesses. Really cheap.
Summit
Jegs
Local hot rod shop.

I split my stock replacement shroud just like a GM shroud.
I cut it in half then added wide plumbers strap to put it back together.

Bolt · Jan 22, 2019

Yes I have a three groove pulley. I'm going to try at 2 groove pulley before I start cutting on the shroud. does anyone know that Ford
part number?

and yes there are different sized spacers. I believe they come in 3/32, 1/2, and up nothing in the 1/4" range that I have found.

tirewater · Jan 22, 2019

Bolt said:
Yes I have a three groove pulley. I'm going to try at 2 groove pulley before I start cutting on the shroud. does anyone know that Ford
part number?

and yes there are different sized spacers. I believe they come in 3/32, 1/2, and up nothing in the 1/4" range that I have found.

Best of luck to finding the correct pulley! Measure your pulley diameter, and go off of that. The easiest solution would be to buy one of the aluminum ones from the vendors, but look at the diameter to make sure you're not under driving your fan and accessories.

Seems every year Ford 302 has a different crank & water pulley size...

My 1976 used D1TE-8312 crank pulley (~6 3/8" dia.), with ~6 1/8" water pump pulley.

bronconut73 · Jan 22, 2019

Moroso has very thin discs to help you dial in that fan.

They are like thick washers as opposed to spacers,

Rustytruck · Jan 22, 2019

Ford used a 3/16 shorter water pump in 1974 and a special pully set with the 7 blade fan and smog pump. That made the fan clear the radiator. Thats when ford started using the 7 blade fan.

Bolt · Jan 22, 2019

Just installed a flowkooler wp. Is there an ideal sized pulley to keep from underdriving the pump?

DirtDonk · Jan 22, 2019

Ideal size pulley you mean? Guessing that's what you meant, but not sure what ideal would be.
Using the same size crank pulley, there's only so much larger you can go on the water pump before it starts to interfere anyway. I think in general the two pulleys are roughly the same diameter on some, and slightly overdriven on Broncos. Like tirewater was saying, about 1/4" difference.
I can't remember if ours are the same diameter or not, but I think not. I believe they overdrive the water pump by just a small amount.

Been wrong before, but it's easy enough to check though.
Since your Flowkooler has a very efficient impeller design that does not cavitate until a very high rpm, you could safely overdrive it pretty far I would think.
But then, since it's also pumping more coolant volume for a given speed, you don't really have to. I never did, and used the stock size pulleys on mine without any trouble.

What pulley setup do you have now? You already up and running without any trouble? If so I would just leave it and see how it works through the summer.

Paul

blubuckaroo · Jan 22, 2019

Bolt said:
Yes I have a three groove pulley. I'm going to try at 2 groove pulley before I start cutting on the shroud. does anyone know that Ford
part number?

and yes there are different sized spacers. I believe they come in 3/32, 1/2, and up nothing in the 1/4" range that I have found.

If you don't need ta three groove pulley, then your fix is easy.
Find a stock two groove pulley.
If you have trouble finding one, Toms Bronco has helped me out a number of times with stuff like this.

bronconut73 · Jan 23, 2019

And if you want to overdrive your water pump. BC has the smallest water pump pulley and the largest crank pulley that will fit,

Bolt · Jan 23, 2019

Thank you, all very helpful

blubuckaroo · Jan 23, 2019

Bolt said:
Yes I have a three groove pulley. I'm going to try at 2 groove pulley before I start cutting on the shroud. does anyone know that Ford
part number?

and yes there are different sized spacers. I believe they come in 3/32, 1/2, and up nothing in the 1/4" range that I have found.

I don't know of any three groove factory pulleys used on a Bronco. Most happen with an A/C install.

rpmgarage22 · Jan 23, 2019

Turn it down on a lathe.

Stock 7 blade fan hitting shroud

Newbie

Newbie

Bronco Guru

Newbie

Grease Monkey

Sr. Member

Bronco Guru

So Cal Broncos

Bronco Guru

Newbie

Sr. Member

Bronco Guru

Bronco Guru

Newbie

Bronco Guru

Grease Monkey

Bronco Guru

Newbie

Grease Monkey

Full Member

Similar threads