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Overdrive water pump pulley for Explorer front dress

ksagis

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Aspiring Bronco Guru
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Jun 15, 2020
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217
I’m pretty sure there’s no way to overdrive the Explorer water pump due to the diameter and bolt circle of mounting flange on the shaft of the pump.

Anybody solve this before?

Pics of a Flowkooler and OEM replacement below to show what I’m talking about.
 

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Broncobowsher

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Jun 4, 2002
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34,947
I want to say that Driven Auto Part once offered one. In aluminum.
They don't make them, they have a machinist who whittles them out. Same as the Explorer conversion pulley for a stock damper.
Since Driven has sold off the property and doesn't do as much as they did when they had the shop it may be hard to get them.
I think it is Wild Horses who also sells the pulleys. So maybe check with them as well.

Or I could be thinking of something completely different. Maybe it is an overdrive power steering pulley I am thinking of?

I know the Explorer waterpump pulley has been unicorn unobtainium material for several years now. Used ones are the only ones available.

Now the good. Since that is a smooth pulley and you don't need to align grooves, adaption can get a lot easier. Knowing the basic dimensions of the Explorer (I don't know them) you could go junkyard shopping and look for something just a hair smaller. Make sure the pilot hole is smaller as well. Find a machinist who can bore the pilot hole out to the Explorer size. That is pretty basic lathe work. Add in the 4 attaching holes. You just made an overdrive pulley. Watch the size and the overdrive. Waterpumps and fans have redlines as well. The silicone fan clutch fluid makes a mess and does not clean up well if you over speed a fan clutch and it blows up. I may have blown up a fan clutch on an engine swap project a few years ago...
 

toddz69

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I think you're thinking of the serpentine pulley with the 3 bolt pattern that Driven had made/sold for quite a few years?

On the water pump pulley, I'm not sure how much OD could be realized since I *think* the i.d. of the pulley is pretty close to the OD of the flange on the pump. Don't have one handy to check but I think that's the case.

Todd Z.
 
OP
OP
K

ksagis

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@Broncobowsher, yes I think you’re thinking of the smaller power steering pulley for the Explorer power steering pump from Driven. Something could be done on waterpump pulley, but would require turning down the OD of the waterpump / pulley mounting flange and updating to a smaller bolt circle to give room to fit a smaller pulley. Complexity spirals quickly.

@toddz69, we ended up at same conclusion.

Attaching pics of a pulley for reference.
 

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DirtDonk

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Well, I’ll be the one to ask then. Why do you need to overdrive and explorer water pump in the first place?
They are arguably the most effective cooling for the Ford V8 platform that we have available today.
Hard to say you may need more water or air flow even at low speeds.
Are you looking to improve either one from an already negative experience? Or just planning ahead?
 
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ksagis

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Well, I’ll be the one to ask then. Why do you need to overdrive and explorer water pump in the first place?
They are arguably the most effective cooling for the Ford V8 platform that we have available today.
Hard to say you may need more water or air flow even at low speeds.
Are you looking to improve either one from an already negative experience? Or just planning ahead?

Mainly leaming, thinking, reading old posts, etc.
 

DirtDonk

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Got it. Well I for one will say don’t spend too much time thinking or concerning yourself with overdriving the water pump in this case.
You don’t need to make it more efficient for 99% of the applications.
If you add on top of the Explorer design, a Flowkooler brand water pump, you have a combination that is hard to beat.
I’ll even go as far as to say that , if you are having a cooling problem when it’s all up and running, it’s not the water pump or airflow that’s giving you trouble.
It’s tuning or something else.

Anyone here have real world experience with the Explorer serpentine setup, with fan, on high horsepower engines that are used hard?
Any shortcomings you have found?
 

ba123

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Yeah, I was gonna ask why as well. I don't think you'll need any more than that Flowkooler pump and if you do then you've got other things you need to spend your time on.
 

ntsqd

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IF, note the capitol letters, IF you were determined to have an OD pulley then look at the pump for the '94-'95 Mustang (I *think* I've got the right vintages). It has a much smaller pulley flange, but appears to bolt on with exactly the same pump gasket. I don't know this for fact as I have not tried it, but I am fairly certain that this could work.

Only downside that I know of thus far is that the Explorer clutch fan will no longer work. Might be worth investigating the Mustang parts if it has a clutch fan. I MAY be possible to put the Explorer fan on a Mustang clutch, donno, hadn't even thought about that until just now.
 

DirtDonk

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Correct. It’s the 94/95 mustang. But like you said, I also have never bolted one up to make sure they are, in fact exactly the same.
They sure look like it though!

One resource, if it’s still available, would be the FlowKooler website. They used to give fairly precise dimensions for their pumps.
You’d want to make sure it’s also the same height from the gasket surface as an explorer pump.
 

DirtDonk

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Of course, if you just happen to be at the nearest auto parts store, you could have them pull both pumps off the shelf and compare them directly.
 

73azbronco

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Nov 11, 2007
Messages
7,835
Pile on, why? Not needed if rest of cooling system is working right. Randy, love him, stopped using the aluminum version because over time they wore with the serp belt.
 

sanndmann3

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Jun 13, 2007
Messages
1,774
Before I went electric fan, I could watch the temp gage drop while going w.o.t. climbing dunes. Explorer mechanical fan pulls lots of air...
 

rocknhorse76

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Bronco owner since 1993 💪🏻
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Jun 7, 2014
Messages
366
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Central WA
Got it. Well I for one will say don’t spend too much time thinking or concerning yourself with overdriving the water pump in this case.
You don’t need to make it more efficient for 99% of the applications.
If you add on top of the Explorer design, a Flowkooler brand water pump, you have a combination that is hard to beat.
I’ll even go as far as to say that , if you are having a cooling problem when it’s all up and running, it’s not the water pump or airflow that’s giving you trouble.
It’s tuning or something else.

Anyone here have real world experience with the Explorer serpentine setup, with fan, on high horsepower engines that are used hard?
Any shortcomings you have found?
I run (or did until I roasted my engine due to issues other than cooling) an exploder front dress with a flowkooler pump, basically stock sized Griffin universal aluminum radiator, exploder clutch fan, and a properly designed fan shroud on my EFI 351W, and it rarely ever climbs above thermostat temperature even when being pushed hard in deep snow. There is no need to overdrive an exploder water pump.
 

rocknhorse76

Contributor
Bronco owner since 1993 💪🏻
Joined
Jun 7, 2014
Messages
366
Loc.
Central WA
I want to say that Driven Auto Part once offered one. In aluminum.
They don't make them, they have a machinist who whittles them out. Same as the Explorer conversion pulley for a stock damper.
Since Driven has sold off the property and doesn't do as much as they did when they had the shop it may be hard to get them.
I think it is Wild Horses who also sells the pulleys. So maybe check with them as well.

Or I could be thinking of something completely different. Maybe it is an overdrive power steering pulley I am thinking of?

I know the Explorer waterpump pulley has been unicorn unobtainium material for several years now. Used ones are the only ones available.

Now the good. Since that is a smooth pulley and you don't need to align grooves, adaption can get a lot easier. Knowing the basic dimensions of the Explorer (I don't know them) you could go junkyard shopping and look for something just a hair smaller. Make sure the pilot hole is smaller as well. Find a machinist who can bore the pilot hole out to the Explorer size. That is pretty basic lathe work. Add in the 4 attaching holes. You just made an overdrive pulley. Watch the size and the overdrive. Waterpumps and fans have redlines as well. The silicone fan clutch fluid makes a mess and does not clean up well if you over speed a fan clutch and it blows up. I may have blown up a fan clutch on an engine swap project a few years ago...
Yep. Cavitation and excessive centrifugal force can do some damage for sure!!
 
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