how much fan clearance?

[oilyrag80]

Im running a 454 with a long pump in my 68 swb project and i finally installed
a 4row rad and the clutch is very close to raidiator. How much clearance is enough? It looks like i have only 3/8 ths or so of clearance.
Thanks in advance

[Stocker]

That would make me nervous. I don't think I'd trust anything closer than about an inch. I wonder if twin electrics -- one on either side of the water pump -- might be a better setup.

[davepl]

Depends how tight the mounts and everything else is, it's pretty close. Keep in mind that the depth of the fan into the shroud is important for cooling, so that it doesn't just churn around its own air.

Normally you want about exactly half of the fan within the shroud.

[BMERDOC]

Originally Posted by davepl

Depends how tight the mounts and everything else is, it's pretty close. Keep in mind that the depth of the fan into the shroud is important for cooling, so that it doesn't just churn around its own air.

Normally you want about exactly half of the fan within the shroud.

Text book explaination! Gets my vote.

[Stocker]

Originally Posted by davepl

Depends how tight the mounts and everything else is

I agree, but everything that is tight enough now can loosen up a bit over time. It wouldn't take much for today's 3/8" to become tomorrow's expensive crunch.

[oilyrag80]

yea i think its to close, is there such a thing as a shorter fan clutch?
I dont want to run electric if at all possible. I wonder what the factoy clearance is
with short pump because everthing else is stock.
There are no fenders mounted but there is almost no movement with the poly bushings.
Thanks

[Frkypunk70]

Perfect canidate for jeep electric fan install.
Posted via Mobile Device

[Stocker]

Originally Posted by oilyrag80

I wonder what the factoy clearance is with short pump because everthing else is stock.

I googled it, found same info on a couple other forums -- 1 9/16" (1.5625") difference, long pump to short pump.

[MikeyMan]

Originally Posted by oilyrag80

I wonder what the factoy clearance is
with short pump because everthing else is stock.

There are illustrations with the water pump dimensions. I remember seeing it somewhere when I was looking up my WP. You could just do the math and see the difference between long vs short. If I recall, it's not too much, like a little over an inch.
Short pump would cause all kinds of headaches lining up pullys and accessories you already have.

I just replaced my water pump in my 72. Mine looks exactly like yours. I have a later 350 with long pump. Same pass. side Alt mount & bracket, and power steering bracket pivot that goes through WP on drivers side.
I have 2 inches between fan clutch and my stock/skinny radiator. I'm not sure about the frame location of my motor, though. It was swapped when I got it. VIN says it was a 6, bracket on frame says Manual Trans. It came with 350/TH350.

Yours seems too close. Do you intend to use a shroud?

[MikeyMan]

Originally Posted by Stocker

I googled it, found same info on a couple other forums -- 1 9/16" (1.5625") difference, long pump to short pump.

Math Wiz!

[oilyrag80]

Originally Posted by Stocker

I googled it, found same info on a couple other forums -- 1 9/16" (1.5625") difference, long pump to short pump.

wow thats more than i thought i guess i shouldent have sold my big block short pump stuff. Ill find another swp setup that seems to be the best solution.
I need to get this right because its hard to keep a big block cool around here in july! Thanks

[ole dollor]

you could go with a flex fan ,or straight drive fan, but i am not a fan of either. the way it is now if you had to stop real quick ,your fan may hit the rad.