Fan different with different types of H2O pumps

NewcScout

NewcScout

Member
Hi guys,

anyone know if there is a difference between fans and different styles of water pumps. Below is the picture of what I have and the old fan doesn't fit over the new clutch flange. Not only that, I don't think it will fit down onto the seat down onto the clutch.
:confused5::confused5::confused5::confused5:
this is on the 345 by the way.

This fan came from the other style pump/clutch setup than what you see in the picture.

Thanks,
drew

2011-07-04_22-33-44_60.jpg
 
There are three different water pump hubs in common use on IH engines.

1. 4 bolt hub for a non-clutch fan blade only.

2. 8 bolt hub for for use with a clutch and fan combo similar to what you have pictured, or a fixed fan can also be used.

3. 1 large center nut with fine pitch, left-hand threads often referred to as a magnetic fan clutch or a big nut fan clutch.

The water pump housings are all the same and will fit any engine in the sv family from 266-392 as well as both 4-poppers. The only difference encountered is with impellers on the pumps, either stamped steel or cast.

Ihc also employed a variety of fans over the course of time. Factors for selection included vehicle platform, engine displacement, and number of belt driven accessories on the engine in question. This could be any where from 4 blades all the way up to 7 with varying degrees of blade size and pitch.

In order to answer your specific question, more information will be needed from you. All we know is the engine is a 345. Not nearly enough. What vehicle is this in? Any belt driven accessories besides the alt/gen? Which water pump do you have now?
 
Thanks for the response scoutboy

I have a 74 s2 with the 4 bolt water pump. The motor came from the po with a big nut clutch.

Oh, and I have an alternator and power steering pump.

Thanks,
drew
 
I had trouble fitting my fan over the new clutch also. It did fit though with some cleaver angling. I held the fan vertical and moved the clutch in all sorts of directions and it went in. Might not work for you but mine it did.
 
Yeah, I think I've tried every possible way of putting it on. I even tried to slightly modify the clutch flange. Still no go. I then measured it and it won't fit down onto the aluminum clutch housing. It doesn't clear the alignment ledges.

The bolt pattern is correct though.

Thanks for the experience tip.
 
The fan pictured looks like the 'hayden' flex blade fan. It doesn't need the fan clutch. The fan mounts directly to the pump, but there would be a aluminum 'spacer' between the fan and the pump. The 'spacer' is to move the fan foreward so the back edge of the blades doesn't hit the crank pully. The foreward edge of the fan will be ~ 1" from the backside of the radiator.
 
bill bennett said:
the fan pictured looks like the 'hayden' flex blade fan. It doesn't need the fan clutch. The fan mounts directly to the pump, but there would be a aluminum 'spacer' between the fan and the pump. The 'spacer' is to move the fan foreward so the back edge of the blades doesn't hit the crank pully. The foreward edge of the fan will be ~ 1" from the backside of the radiator.
Click to expand...

There are many variations of the so-called "flex fan" hub system now marketed by hayden. And many of them do use a thermo-control fan clutch.

Likewise, there are several different fans used on all the variations of the ihc-produced I-4 and sv engines.

And...there are several different variations of the air-off side of the radiator core top the front of the actual fan hub used, that depends upon the oem configuration also, their is no specification for this. Once a radiator is added that includes an additional row, then the air-clearance dimension changes significantly.

The "eight hole" hub version of the water pumps incorporate two different fan hub patterns so that they can be used in various applications. The four hole water pump will fit only one single fan hub configuration.

The fan hub dimension of the hayden-type fan clutch will fit either fan hub. The hayden clutch (also sold under many other different brand names) is the only unit available now for purchase. The oem clutches went away many years ago.

The fan hub used on the thread-on fan clutch will not fit any other hub configuration, the holes don't align and one should never use a drill bit or do any sort of machining on the fan unit itself, that is death calling!

Fan hub "spacers" are used only to correct a fan-to-radiator spacing issue. The problem is setting the fan to the radiator with a spacing of 3/4" while keeping the fan blades properly aligned with the perimeter of the fan shroud.

We have much information posted on this exact issue in several other threads right here in this sub-forum.
 
Bill,

I know this fan came off a clutch because I still have the old clutch that I removed it from. So it May not be a "hayden".


So then....
From what I'm hearing, I guess I need to find a new fan.

Is there a way to id a fan that would work on this clutch? I'm thinking that this is a salvage item only?

Thanks,
 
Correct fan assemblies are available from any full service parts house. Simply match the hub configuration and diameter. The aftermarket fans are normally supplied through hayden or one of their sister companies.

Also, Jeff has fans of all sorts right up the road from you at ihon in Grass Valley! Give 'em a call at 530.268.0864.

The center hole of the fan must match the center pin on the fan clutch or spacer used, perfectly. That is the location device for this assembly, not the four retainer bolt holes.
 
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