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Discussion Starter · #1 ·
Clutch fan for 4.2 won\'t fit

DDawg16 was nice enough to sell me a clutch fan and shroud off a 84 CJ 4.2 to help with my slight overheating issues. Well the shroud fit's perfectly, but the clutch fan assembly is simply tooo thick to fit between my water pump and radiator.

I did replace the stock two core with a three core about two years ago, but it fits into the same mount and I don't believe this is the problem as I need at least 3/4 to an inch more room to fit the clutch fan.

Also, the pitch of the blades on the clutch fan seem to be backwards (clockwise vs counter clockwise). What's up with this? Without a serpentine belt type system how could his fan run backwards compared to mine?

By the way, I current have the small four blade solid fan on my 79 CJ7. Any thoughts on what I need to get or do to make a clutch fan work? /ubbthreads/images/graemlins/confused.gif
 

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Re: Clutch fan for 4.2 won\'t fit

I should be getting a taurus fan from ebay today (Price went up) and will put it in tonight or tomarrow, I will let you know how it goes, I have a 2 core though.

BTW: the fans are different for serpentine vs V belt.
 

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Re: Clutch fan for 4.2 won\'t fit

That is strange. I have a 3 core as well and my clutch fan seems to fit just fine, but there really isn't much room left. I have put that thing into the radiator a few times when i was wheeling a little to rough.
 

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Re: Clutch fan for 4.2 won\'t fit

Ouch. Makes me happier about my free taurus fan.
 

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Discussion Starter · #5 ·
Re: Clutch fan for 4.2 won\'t fit

Yeah but serpentine didn't even start till 87 right? Anyway, I've got a Caddi electric fan I might work on this winter or maybe run by the parts store and see if the clutch assembly for my year is skinnier. /ubbthreads/images/graemlins/wall.gif
 

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Re: Clutch fan for 4.2 won\'t fit

I think the water pump turns the opposite way with a Serpintine setup. That's why the fan is reversed.
So who knows what the flange on the water pump is set at.
 

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Re: Clutch fan for 4.2 won\'t fit

My 88 has v-belts.
 

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Re: Clutch fan for 4.2 won\'t fit

[ QUOTE ]
Yeah but serpentine didn't even start till 87 right? Anyway, I've got a Caddi electric fan I might work on this winter or maybe run by the parts store and see if the clutch assembly for my year is skinnier. /ubbthreads/images/graemlins/wall.gif

[/ QUOTE ]

My 82 CJ-8 - that began it's life in Kalifornie - had a serpentine belt and clutch fan. I've also noticed the CA 258 sits about 1/2-3/4 of an inch further back than my non-CA CJ-8's engine.
 

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Re: Clutch fan for 4.2 won\'t fit

All that headach. I just got a 16" flex-a-lite elc fan. $99
2500cfm works pisser. dont even need the shroud anymore and you dont need the motor spining that thing all the time to.
 
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Re: Clutch fan for 4.2 won\'t fit

Man, now I feel really bad.....I didn't know there would be a difference....

Mach2....your going to have issues with the flex-a-lite....I had the same one...it was fine for everyday driving...but when you start rock crawling at real low speed, it just does not keep up. It appears that the Taurus fan is about the only electric that really works.

The only reason I'm using the Taurus fan is because I don't have enough room with my SBC to fit the belt driven one.

Ok....we gotta help jdoggmoney.....I'm feeling real bad that the fan does not fit.....
 

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Re: Clutch fan for 4.2 won\'t fit

Here's what I found out. '79 CJ-7 258 without fan clutch and I think factory HD cooling(3 row rad?). Parts Jeep: '85 CJ-7 258 fan and clutch. Put the '85's motor in the '79, no room for the fan clutch. Start looking. The radiator cutout/offset in the grill shell was deeper for the '85, effectively moving the radiator forward. Also the '85's rad seemed to be offset with it's mounting brackets? Also the '85's rad. was only a 2 row I think. The water pump pulley and the pump itself were squatier for the '85. Also the rad. cap for the '79 is in the middle along with the hood being dimpled in the middle for clearence, the '85's rad. cap is offset to the driver's side with the same dimpling. I've got no overheating issues just rust ones. When the front fenders go I'll replace the '79's grill shell with the '85's and put in the big fan/clutch/shroud/factory overflow bottle.
 
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Re: Clutch fan for 4.2 won\'t fit

That would make sense....the radiator for my 84 was recessed into the grill by almost an inch.

But we still have the issue of the reverse rotation of the fan.

Jarret....I would be willing to bet that your existing 4 blade fan will be fine with the fan shroud. The shroud makes a world of difference. I think I need to send some money back to you....keep the fan...shipping is as much as what the fan is worth.
 

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Discussion Starter · #14 ·
Re: Clutch fan for 4.2 won\'t fit

No worries. I'm sure one of the hundreds of Jeepers here in the middle of no where will need a clutch fan or clutch sometime down the road. I can think of two that went earlier this summer.

The shroud fits well and is probably helping, but the diameter of the solid fan is smaller leaving about a 2 inch gap between it and the edge of the shroud. So it's not being as efficient as it could be. Either way, the shroud is worth what I paid you. (Or should I say paying..honest it's on the way. /ubbthreads/images/graemlins/blush.gif)

I have access to several solid fans from GM V8's. This weekend is our local Jamboree and it's surprisingly cool, but next week I will try and find a larger diameter flex or solid fan to really get the air moving through the shroud.

I too am stil somewhat perplexed about the pitch diferences. Unless I'm overlooking something obvious, a serpentine belt system is the only way this could work.

I guess you can chalk this up to one of those "Jeep Things", maybe one day I'll understand. /ubbthreads/images/graemlins/grin.gif
 

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Re: Clutch fan for 4.2 won\'t fit

As far as I know serpentine belt systems had a reverse rotation water pump and ergo a reverse rotation fan. The fan still pulled air back into the engine compartment only with the fan spinning in the opposite direction, thus the blades will have a reverse pitch(angle). There were some '85's that had both, a serpintine belt and numerous v-belts, a setup I much perfer. When I put the '85 engine into my '79 I put a new water pump on it. The parts guy in his infinite(NOT-most definitely finite) wisdom asked me if it was a reverse rotation pump. I looked at him like he had 2 heads and asked how do I tell. The other counterman asked did it have a serpentine belt? This potential mixup has led to several cooling system problems when a reverse rotation pump was put on a normal rotation installation. The pump will sorta work, but not reaL good.
 
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