Fan Clutch

So I have a 68 Dart with the 225 slant six. I have an aftermarket aluminum radiator in it. I would like to put in a clutch fan. I am currently running a 6 blade flex fan, which cools it fine, but it is loud and is probably taking up to much power (this is a convertible so it needs all the power it can get).

The problem is that the radiator is 2 rows, it is a lot "thicker" compared to the OEM replacement one row. And the standard fan clutch pushes the fan into the radiator (not good).

So I was wondering if anyone had this problem? I do not want to change the radiator out due to it working extremely well.

Would anyone have a part number to go on for a shorter shaft fan clutch?

How much room do you have to work with? The Hayden clutch(part #2765) is 2.67" tall.

1. The Hayden #2765 is about the shortest you are gonna find. If it won't work, probably nothing will.
2. Why not just ditch the flex fan? They are noisy. I had one on my small block Vega that threw a couple of blades. Off of course you're not gonna see that kind of rpm's on your car . Get a regular fan. They are quieter and easy to find.
3. I just don't think you will see(or feel) any power gains on a slant by changing the fan.
JMO Dennis.

valiant1966 said:

Why not just ditch the flex fan? They are noisy. I had one on my small block Vega that threw a couple of blades. Off of course you're not gonna see that kind of rpm's on your car

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Regardless of the RPM's, always keep an eye on the flex fan blades for cracks; they are pretty famous for that, and for throwing blades.

The best I can figure from power gains will be a few HP at interstate speeds, This MIGHT translate into an mpg or so of mileage gain, since the running HP to keep the car moving at those speeds is probably in the 50-60 HP range or therabouts.

BTW, I have been looking at the same issue; I have about 3.2" of clearance between the fan pulley front surface and the back of the radiator.

Note that the Hayden 2765 has a mounting flange outer diameter of 2.32"; that is only slightly larger than the /6 water pump's fan bolt circle diameter of 2.06". The bolts' threads will actually be slightly outside of the ends of the mounting slots on the flange slots and may have a tendency to bend or walk out when tightened in the 2765 flange. Backing the bolt heads with hardened flat washers, and using at least grade 5 and maybe grade 8 bolts, might help this. I would surely locktite them in.

Also, the 2765 has a pilot hole in the flange with an ID of .75"; the /6 water pump's pilot is .62". So a centering ring of .75" OD and .62" ID is needed. You might find some 3/4", 1/16" wall tubing for this, or carefully bend a ring out of 1/2" wide x 1/16" flat stock. Aluminum will probably work if you put a bit of anti-sieze on the inside. You don't want to run this without the clutch pilot hole being snug on the pump's pilot nub, especially with the flange bolt fit discussed above.

I don't have a drawing on the Hayden fan for this (3619 or 3618) to see if if sets so far back as to hit the belt or anything behind the fan area. This thread says the front of that fan is behind the front of the clutch, so if the clutch clears your rad, then the fan will too.
http://www.forbbodiesonly.com/moparforum/archive/index.php/t-50927.html

I have also been looking into the Hayden 6200/6201 clutch which is short too; it is for a Kia Sportage L4 (1997-2001). The fan is smaller and plastic but looks to be a pretty short fan that might give better clearance towards the blet and such. But cooling whne the car is stopped is probably less due to the smaller fan size. And, it has some pilot issues too that are take some mods to the water pump's pilot nub, and the 4 flange mounting through-holes may need to be moved a bit.

Same problem with my 64 slant. A p.o. put a radiator of unknown origin. Works, but not enough room for even the standard fan w/ spacer. It had no fan and a M-B electric pusher (always on w/ ignition) when I bought it. I'll keep the electric (good for AC), but add a thin nylon fan from Summit like I put on my 65 Dart.

If you truly want the thinnest clutch fan you can find, look at Euro cars (Volvo or M-B), since they are much thinner. Fooling around, I found a Mopar clutch fit my 1985 M-B diesel water pump, using the smaller spacer ring in the box, though the thick Mopar fan hit the water pump outlet. Going the other way, you would need to drill the centering hole bigger to fit a Mopar w.p., but the 4 bolt slots would fit. Those parts are expensive new, but cheap at the junkyard. If an 82-85 M-B get one w/ a nylon fan since the cast alum fans are known to fail.

Thank you for all this information, it looks like I have a bunch of research I have to dig into. Thanks a bunch!