clutch fan gap too short

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Did they even come with a clutch fan back then? That would explain why it's all so tight. Is the radiator support one that has a "filler panel" for the /6 radiator? Maybe there is a fabrication solution there.
 
Did they even come with a clutch fan back then? That would explain why it's all so tight. Is the radiator support one that has a "filler panel" for the /6 radiator? Maybe there is a fabrication solution there.

Good question.

The trouble is the water pump. Years ago when the original 273 engine failed I went to rebuild it but at the time pistons were totally unavailable. So I built up a warmed over 360 because they were cheap and easy to source. The trouble is that in doing so a bunch of other stuff has to be modified for an early A - like the newer style water pump which is much longer than the original cast iron unit. If I was still running the 273, which I often wish I had in the bay instead, it wouldn't be a problem.

Side note: the 360 also necessitated getting the radiator inlet and outlet ports swapped to suit the new pump, and another core added to the mix. Both of those changes fill up the gap between the pump and radiator fins.

The problem is worse for a /6. It's a long engine with an even shorter gap between the fan and radiator fins. I want to say 2"?

So sure, I could cut and hack and weld a little to fabricate mounts and move the radiator forward but it's a lot of cutting that I'd rather not do to a nice car. The clutch fan is the more elegant solution.
 
Did they even come with a clutch fan back then? That would explain why it's all so tight. Is the radiator support one that has a "filler panel" for the /6 radiator? Maybe there is a fabrication solution there.
Nope they did not come with a fan clutch with the slant six. Yup the radiator core will need to be pushed back towards the grill by 1/2 inch to clear that 1969 Volovo fan clutch, thats the biggest issue.
 
2.32 inch tall is the Volvo Hayden fan clutch, the hayden 2947 one is 2.7, Electric fans will free up H.P how much i dunno.

s-l500.jpg
 
That is tight! That's what my setup looked like with the Hayden 2947 unit. I'd be afraid to corner too hard with it so close there. Thankfully my car doesn't exactly corner. Heh.
Yup, exactly the motor can move forward if you brake hard, and even more if the mounts are worn out.
 
That 1/4" was taken up by your motor plate, but if he did it, that would throw his pulley/belt alignment off, no?

Yes , that aint real hard to over come , my GM 130 amp alternator sits where the fuel pump would normally be on a 440 , making things line up aint that hard , trial and error-------
 
Yup, exactly the motor can move forward if you brake hard, and even more if the mounts are worn out.

No problem w/ engine fore and aft limiters.
I really got a little better cooling out of a fixed fan , just trying to eliminate all parasitic drag , my 440/505 doesn`t run like I think it should !
 
yes..use a proper 7 blade mechanical or mopars' own flex fan.If your cooling is compromised you will surely over heat idling with the clutch fan...and when they fail it's no fun.
 
yes..use a proper 7 blade mechanical or mopars' own flex fan.If your cooling is compromised you will surely over heat idling with the clutch fan...and when they fail it's no fun.

Mine doesn`t over heat , but runs about 5-6 * hotter w/ the clutch set up -
Leaving the carb/throttle body pan/scoop seal to the hood will make it about * hotter in cool weather even .
 
Good question.

The trouble is the water pump. Years ago when the original 273 engine failed I went to rebuild it but at the time pistons were totally unavailable. So I built up a warmed over 360 because they were cheap and easy to source. The trouble is that in doing so a bunch of other stuff has to be modified for an early A - like the newer style water pump which is much longer than the original cast iron unit. If I was still running the 273, which I often wish I had in the bay instead, it wouldn't be a problem.

Side note: the 360 also necessitated getting the radiator inlet and outlet ports swapped to suit the new pump, and another core added to the mix. Both of those changes fill up the gap between the pump and radiator fins.

The problem is worse for a /6. It's a long engine with an even shorter gap between the fan and radiator fins. I want to say 2"?

So sure, I could cut and hack and weld a little to fabricate mounts and move the radiator forward but it's a lot of cutting that I'd rather not do to a nice car. The clutch fan is the more elegant solution.
Simple solution is just to use the iron water pump, and the original 273 alternator brackets and all pulleys. They will fit a 360 no problem, and the hoses will now fit the original radiator. The iron pump is shorter and a fan clutch will fit easily. The only problem will be that the timing marks will be partially hidden under the lower radiator hose, but even that can be fixed by using the 273 front cover. The 273 damper won't work on 360, though, as a 273 is neutral balanced and the 360 is externally balanced. However, the 360 balancer can be used with the early timing cover simply by marking the TDC to work with the 273 timing cover.

DSCF0106.jpg
 
The parasitic loss of the fan is minimal all things considered.

If the fan is pushing 100 CFM ( just a number for illustration) and you are driving fast enough to push 100 CFM past the fan there would be no parasitic loss. If you are going fast enough to push 150 CFM it could be argued that you are actually adding power to the system.

If you have an electric fan plug it in, it pushes air.
Now use your compressor and blow air at its inlet. With enough air you can make the fan spin faster.
If you measure the current it will be higher without the compressor blowing on the fan and lower when it is.



direct drive vs. viscous fan drive.jpg
 
Assuming you have an original type radiator and not one of the newer aluminum jobs, you can also pick up some clearance by using a propane torch to melt the solder holding the radiator brackets to the core, moving the core forward, and resoldering. Have to be careful not to melt the solder sealing the tanks to the core. How much will you be able to move it? Depends.
 
@65 Cuda 340
A lot of unknowns about the chart.
Was that measured with air of various speeds blowing on the fan?

Was the viscous fan the same diameter, number of blades and pitch as non viscous fan?

Most of the time our engines are not at 3500 RPM or greater. If you are drag racing I would not want a viscous fan rotating at 4000 to 6000 RPM, wouldn't want any fan rotating that fast.

I'm not flaming you I just do not feel the chart is presenting a complete story. On a Dyno sure, fan draws power. In the real world the difference in nominal.

If you want ultimate power from the engine add a second battery. Have electric fans, elec water pump, and elec power steering pump. The battery is not hooked up to the alternator it is only externally charged, you just gained 5 hp, remove the alternator too and use another battery externally charged to start the car, 1 more hp, at 3000 rpm. Sounds silly, but if you are going for the parasitic losses....

Just my 2 cents
 
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there is the original hemi short shaft clutch fan or it's replacement but near impossible to find.I thought Hayden started producing a short shaft model for clearance problems.
I have never had good luck with clutch fans, they have all been a problem or barely adequate at best.
 
Fail fail fail.

I picked up two fan clutches for a W116 Mercedes, a Uro unit and used original MB unit and both clutches are exactly the same width as the Hayden unit. Specifically I bought parts for a 1977 Mercedes 280se and a 1979 450sel.

Also picked up a complete Toyota Tundra / 4Runner assembly that SSD provided a link for:

TOYOTA TUNDRA TACOMA 4RUNNER T100 COOLING RADIATOR FAN BLADE AND CLUTCH 3.4L V6 | eBay

.. but it's over an inch too long. Measuring at 3.8".

Also bought a fan from Rockauto, the only Mercedes unit they sell, and sure enough the fan blades spin the wrong way.

So despite the claims none of the units I've bought so far work at all. Still sniffing around the boneyards for a Volvo unit.

Of note is that I've spent some time on Mercedes-Benz forums and found that they dislike nearly all the aftermarket fan clutches because of the high failure rate. Apparently the stock unit, made by Sachs these days, is $550. So even if it fit it would be much too expensive. So my summary is that the MB parts just won't work.

I'll keep looking in the same of science.
 
What is the final setup you are trying to cool ?

Engine, transmission ??
Slant 6 with 904
273 with 904
360 with 904
360 with 727 ??

What year and model car . . ?

Why are you looking at all the foreign parts to try and get your spacing right ?
 
What is the final setup you are trying to cool ?

Engine, transmission ??
Slant 6 with 904
273 with 904
360 with 904
360 with 727 ??

What year and model car .
Im thinking it is an early A and a \6 based on the info from the posts, and the OP is trying to eek out an extra HP or 2.

Thanks for the reply. I'm not so much looking for extra cooling as I am just trying to reduce parasitic loss. I don't mind fabbing something together
I found a possible solution for a Mercedes clutch and fan. I ordered parts from Rockauto and will report back my findings once they arrive. If it works I'll provide part numbers. Useful for early-As with aluminum water pumps and /6s.
If I was still running the 273, which I often wish I had in the bay instead, it wouldn't be a problem
 
Im thinking it is an early A and a \6 based on the info from the posts, and the OP is trying to eek out an extra HP or 2.

No, it's a '65 Barracuda with a warmed 360 and an A833. It's not a HP race for this project. I'm simply solving a problem I felt needed attention. This topic has come up many times here at FABO. It seemed a good moment to do some research.
 
What is the final setup you are trying to cool ?

Engine, transmission ??
Slant 6 with 904
273 with 904
360 with 904
360 with 727 ??

What year and model car . . ?

Why are you looking at all the foreign parts to try and get your spacing right ?

Why not foreign parts? I'll use whatever works and could care less what car it's from. The slimmer Hayden unit was too large already. Looking through hints from the /6 guys and the fan clutch catalogs the slimmer units happen to be in "foreign" applications.

The MB and Toyota units come up from time to time here and elsewhere. The Volvo clutch fan happens to the thinnest available in the Hayden catalog that still mounts with the correct bolt circle for the water pump.

If it doesn't work out I'll either skip the clutch or swap out the front engine cover and install a cast iron water pump.
 
Fail fail fail.

I picked up two fan clutches for a W116 Mercedes, a Uro unit and used original MB unit and both clutches are exactly the same width as the Hayden unit. Specifically I bought parts for a 1977 Mercedes 280se and a 1979 450sel.

Also picked up a complete Toyota Tundra / 4Runner assembly that SSD provided a link for:

TOYOTA TUNDRA TACOMA 4RUNNER T100 COOLING RADIATOR FAN BLADE AND CLUTCH 3.4L V6 | eBay

.. but it's over an inch too long. Measuring at 3.8".

Also bought a fan from Rockauto, the only Mercedes unit they sell, and sure enough the fan blades spin the wrong way.

So despite the claims none of the units I've bought so far work at all. Still sniffing around the boneyards for a Volvo unit.

Of note is that I've spent some time on Mercedes-Benz forums and found that they dislike nearly all the aftermarket fan clutches because of the high failure rate. Apparently the stock unit, made by Sachs these days, is $550. So even if it fit it would be much too expensive. So my summary is that the MB parts just won't work.

I'll keep looking in the same of science.

I dont recall the number , but my hayden clutch is 2 5/8'' tall if I remember right , is a ***** trying to get nuts started on the studs I cut down had to barely leave enough for a nut . Their so short I cant even run a washer under them . Had to make them that short , or couldnt get a nut started , bolts are out of the question for moine
 
What is the final setup you are trying to cool ?

Engine, transmission ??
Slant 6 with 904
273 with 904
360 with 904
360 with 727 ??

What year and model car . . ?

Why are you looking at all the foreign parts to try and get your spacing right ?


In my case a 440/505 in a 68 fastback , probly one of the worst combinations for fan clearance , has to have a big rad. to go with it sinse it aint close to anything stock.
 
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