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#1226161 07/18/2017 10:25 PM
Joined: Jun 2013
Posts: 148
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Shop Shark
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I want to change the standard 4 blade fan to a 6 blade high output fan. This is a 1954 pu with 235 motor. My problem is with the waterpump hole on the original fan is 1".All the aftermarket ones are much smaller at around 5/8". I want to add a/c next year and I already made a fan shroud. Has anyone found fans to fit over the waterpump pulley?
Thanks
Tony

Joined: Apr 2005
Posts: 7,440
Bolter
Bolter
Joined: Apr 2005
Posts: 7,440
Could you use a drill press and enlarge the 6 blade center hole to fit your water pump?
🛠


Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
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Kettle Custodian (pot stirrer)
Kettle Custodian (pot stirrer)
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Since when is making a hole BIGGER a problem?
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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Well Jerry if I can keep it centered I might give it a try. I could take it to a machine shop. Those are both good ideas, thanks guys
Tony

The fan was only $35 at Summit Racing so that's not much

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yar Offline
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“Has anyone found fans to fit over the waterpump pulley?”

Tony,

Is it the water pump pulley or shaft you want the fan to fit over? If it is the shaft and we were neighbors I would suggest either of these options and then we would do one in my home machine shop.

1. Remove the water pump and reduce the diameter of the shaft in front of the pulley to the size of the fan hole using the lathe. That approach is totally doable unless the shaft is hardened. You can determine that by trying to scratch it with a file.

2. Put the fan blade on the milling machine table and center the existing hole under the spindle. Then, using a boring head, bore the hole to the size of the water pump shaft.

Even if you had a 1” drill and a drill press capable of holding it, drilling sheet metal like a fan blade hub generally yields an inaccurate (and often somewhat triangular) hole.

Like all challenges, your has a solution.


Ray
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Just ordered the fan blade and when it comes in I will take it to a machine shop.

Many thanks fellas

Tony

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All you need is a drill press and a handful of drill bits. Enlarge the hole 1/16" at a time and the drill will self-center in the previous size hole. Don't go to some sort of ridiculous lengths like some self-appointed know-it-alls suggest. Take your time, be careful and use a little common sense!
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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'Bolter
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I like to use these step drills for this type of thing especially since I don't have 1" bits.

https://www.harborfreight.com/2-pie...-high-speed-steel-step-drills-96275.html

Dennis


40 Chevy 1/2 ton
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Renaissance Man
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There is a step drill which is made for sheet metal (different than what Dennis found). It has closer increments of steps and does not catch the sheet metal and destroying the part. They are somewhere around $20-$30 range. Electricians use them for drilling holes in panel boxes. They are nice.
Carl


1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
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yar Offline
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Tony,

These brief articles explain why drills make odd shaped holes in sheet metal and offer a suggestion to solve the problem:

http://timbobtastic.com/hints-and-tips/drilling-a-round-hole-in-sheet-metal/

http://www.giangrandi.ch/mechanics/sheetmetaldrill/sheetmetaldrill.shtml

Pretty interesting, huh?

Last edited by yar; 07/19/2017 4:05 PM.

Ray
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Riding in the Passing Lane
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I think your advise is real good Yar. We don't all have 5/8 to 1" drill bits in 1/16 increments.
George


They say money can't buy happiness. It can buy old Chevy trucks though. Same thing.
1972 Chevy c10 Cheyenne Super
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yar Offline
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Thanks for the compliment George. I wish Tony were my neighbor so I could help him with this. Even for those of us who do have those big drill bits they don't work very well in sheet metal as the illustrations in those articles show. That's why hole saws and punch presses are used in sheet metal.

It's really fun having a hobby machine and welding shop and benefits my neighbors too. I'm the neighborhood machinist/welder. Other neighbors have a backhoe, tree climbing equipment for serious tree work, computer skills, etc.

Last edited by yar; 07/19/2017 8:13 PM.

Ray

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