Fan Clutches

[Moparman01]

I'd like to put a clutch fan on my 440 powered 69 Charger, but i'm not sure which clutch type i need. First of all, several years ago i tried to install a clutch fan in the car but had clearence issues, the clutch was less than a 1/4" away from the radiator, to close for comfort! I ended using that fan clutch on my fathers 70 440 Cuda and it fit fine with plenty of clearence, i don't understand what the difference would be? Anyway, i've read there is "short shaft" and "long shaft" clutches, obviously i need the short shaft, but all the clutches i look up do not specify either long or short? My father works for an auto parts shop and even he is having trouble finding one that will fit. What's an exceptable amount of clearance between the clutch and rad.? What are u guy's using for clutch fans? Thanks! 

[bill440rt]

Big question: has your cooling system been modified in any way? Thicker or aftermarket radiator, shroud, fan, etc?
Is your car an original 440-powered car? If so, that would explain why your dad's clutch out of the Cuda fit. If they were both original, they would have had the same fan clutch ending in a part number with "070". Like you've discovered, these have short shafts hence the more clearance.
The fan clutch out of the MP viscous fan package supercedes the "070" clutch & is really for truck applications (part number ends in "704"). It has a slightly longer shaft & brings the clutch closer to the rad. If your rad is stock thickness, you can get away with it. But, if it's been recored now the fan is too close if your core is thicker.
Best bet is to take a measurement from the water pump shaft face (where the clutch would mount) to your radiator. That will give you the overall height of the clutch you need.

BTW, "070" clutches are becoming rather hard to find. They can be expensive if you find a good one.

I believe some members here are running a Jaguar-based fan clutch, which provides them enough clearance. I've never used one, so I cannot comment on performance.

[bill440rt]

BTW, how did you make out with your rad support opening & cooling issue?? 

[Cooter]

Don't know if Mopar Perf. has handled this problem yet or not, but the last one I saw from MP was WAY too long..NO Clearance.

[bill440rt]

This may also depend on rad thickness. The dimensions of the MP clutch has not changed, it is the same "704" clutch used for years.
I have one in my '68 with a 440, 26" rad with the stock thickness, stock 7-blade fan. It is tight, but there is enough clearance (about 3/4" - 1" or so). Other people I know run the same setup.
IIRC it will NOT clear a 22" BB rad, because they are thicker.

[bill440rt]

BTW, the "070" clutch were for cars without A/C. The offering with A/C was a "456" clutch. Same short shaft, however had a spring on the front of it just like the current "704" clutch.
Attached are pics. This one is NOS.
You might be able to find them NORS or used from Eaton or TRW. They made over the counter offerings with the same dimensions. They have been NS1, so you might have to search a bit.
From what I hear the Jaguar clutches will work, but I think the mounting pad is a little different size so you have to use larger washers with the bolts to attach it.

[justcruisin]

Hayden 2765, Jaguar clutch. about the shortest you will find.

[Cooter]

Word of caution: 1" Clearance may or may not be enough as when the clutch "Kicks in", the blades "Flex/Twist" and i have torn up many a radiator with minimal clearance.

[Moparman01]

BTW, how did you make out with your rad support opening & cooling issue?? 

Thanks again for all the info Bill! Actually i just cut the core support open last night, came out ok, used a cut off wheel and got a pretty straight cut. I am gonna reinforce it a little bit before i put the rad. back in. With that said, the rad that i have is stock core thickness, Chrysler 26" 3 row, exact same as in my fathers Cuda. My Charger was origionaly a 318 car, my dads Cuda was also a factory small block car as well. I believe the clutch and fan i origionally bought was the viscous fan set from Mancini, i didn't fit my car but did it fit the Cuda! I currently have a fixed flex fan on the motor, with the rad out i want to go to the solid blade fan with a clutch, i think that, along with the opening the core support will really make a big difference on my over heating issue.  

[bill440rt]

Great news! 
You should have much more airflow now thru the rad.

The viscous fan set from Mancini is most likely the MP kit. If your 26" rad is stock dimension the clutch should work, however I've never had luck fitting with the fan itself. Try to locate an original heavy-duty 7-blade fan. You'll find them used all the time on eBay or maybe a member here has one.
Here's one just doing a quick search on eBay:
http://www.ebay.com/itm/MOPAR-1968-71-426-HEMI-440-COOLING-FAN-2863216-CUDA-CHALLENGER-ROADRUNNER-GTX-/170910319435?pt=Vintage_Car_Truck_Parts_Accessories&hash=item27cb0c834b&vxp=mtr

Once you have your rad in place, compare the measurement & just try to fit up the MP clutch. You should have some room there. If not you may have to find a shorty.

BTW, even if the clutch is 1" away from the rad the fan still mounts on the backside of the clutch. If you use the 7-blade fan the blades will be at least 2" away from the rad. Even if the blades flexed completely straight they are still not gonna hit the rad. The 7-blade fan is a pretty sturdy unit, it won't flex.
I've had this setup going 10+ years in my car, there is not even a scratch on the radiator. 

[Cooter]

Good luck.

[Moparman01]

Hayden 2765, Jaguar clutch. about the shortest you will find.

I've heard about the Jag clutch before but never really looked into it. I see summit racing sells that clutch, but there are zero specs on it. Can you tell me if the pilot hole is correct? Also, will a standard Chrysler 7 blade fan bolt right to it? From the pics it definatly looks pretty short, would probably do the trick for my set-up.

[justcruisin]

The pilot hole is different, overall the clutch is 0.800" shorter. Google: 2007-hayden-fan clutch.pdf  all the specs are there.

[jlatessa]

A bushing came with my Jag clutch from NAPA, so it fits fine.

Joe

[Moparman01]

I threw the radiator back into the car today to take some measurements. From the face of the rad. to the face of the pump pulley i have 3-1/2" at the top and 3-1/4" at the bottom, so yeah it's already fairly close. My father picked up a fan clutch at the parts store he works for today just for grins and giggles and it was touching the radiator! It was a Chrysler product fan clutch, i measured the height of it and it is a total of 3-1/4" tall. With that said, i do have a "jaguar" clucht on order but it won't be here till thursday, but unless the Jag clutch is (or less than) 2-1/4" tall total, no way will it work either! So, does anybody know the exact height of the Jag clutch? I've looked on there web site but can't find any specs, the "pdf" file keeps freezing up on my computer. Thanks!

PS., My core support cut was dead on the money, i'm happy with how it turned out!  

[justcruisin]

The 2765 clutch is 2.67" in total length, I doubt you will find a clutch 2 1/4" that will work, you may have to use a fixed fan and fab up a spacer or go electric.

[Moparman01]

Yup, that's only gonna give me a 1/2" clearance at the bottom and 3/4" at the top, i just feel that's a bit to close for comfort. Would it ever hit, probably not but if it did that would be a mess! Well, i have good solid 6 blade set-up on my 68 Charger (not on the road anyways), i'm gonna pull that off and put it in the General today and get it back together and running. Thanks for the help!

[charger Downunder]

If your fan runs close to the radiator keep an eye on the rear engine/ gearbox mount if you lose the mount bolts the hole lot will move forward and fan will kiss radiator. Same if mount wares out.