Pulley ??

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Kent mosby

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Kent mosby said:
Will a small block water pump pulley fit on a big block water pump? Shimming needed? I am looking for a pulley around 6 inches in diameter and has around 2.7 inches deep. Small block pulleys a little smaller than big block but they are listed as the same bolt pattern and 5/8 inch locator.

Chrysler Small Block Water Pump Pulley - 2 Groove

Big Block Chrysler Water Pump Pulley 2V
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Both of those are well over 6 inches in diameter. The BB pulley is 6.9 inches. Hard to even get to 1:1 with those sizes.
 
I found a 7.5 inch 4 groove crank pulley but the 6.9 inch water pump pulley will not fit, just barely. The 6.4 inch would fit. Why is it that you cannot find an overdrive set of pulleys? Makes no sense.
 
Kent mosby said:
I found a 7.5 inch 4 groove crank pulley but the 6.9 inch water pump pulley will not fit, just barely. The 6.4 inch would fit. Why is it that you cannot find an overdrive set of pulleys? Makes no sense.
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The 7.5 crank pulley with a 6.4 inch water pump pulley would be 15% over and that would be smoking if you can get the crank pulley. Who has that pulley??? I’d just machined off the unneeded grooves.

You can’t hardly buy overdrive pulleys because it became the trendy thing to underdrive the water pump to save 3 horsepower, which of course costs 20 or more horsepower because the engine temp can’t be controlled.

Sometimes a horsepower gain on the dyno is an power killer in the car.
 
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I picked it up on eBay. I was going to try to use my pulley from 440 source. But it just barely doesn’t fit. I need maybe 1/8 inch more clearance. Would the small block one be useable with shimming?
 
Kent mosby said:
View attachment 1715756941 I picked it up on eBay. I was going to try to use my pulley from 440 source. But it just barely doesn’t fit. I need maybe 1/8 inch more clearance. Would the small block one be useable with shimming?
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I don’t know if the SB WP pulley would work. You’ll have to mock it up and see.

It’s a real pisser that no one wants to make over drive pulleys. March Performance said they would, but it was a 2k investment at a minimum for me. I don’t want to do that because I’d get zero ROI. And they don’t want to do it because they think no one would buy them. He probably isn’t wrong because the vast majority of folk still think you can move the coolant too fast through the radiator. Until that sacred ox is gored, we are screwed. It’s a tough sell to get people to unlearn something they think they have know for decades and get them to learn something new.
 
mopowers said:
Does anyone even sell a pair of overdrive single v-groove pulley for a SB or BB Mopar?
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Not that I can find. The March Performance serpentine belt pulleys are overdrive. I put a set on the 73 Junk S#*t Duster but I forget how much overdrive it has. 6% or something like that.
 
I have a buddy putting a 400 in a '67 Dart right now. I tossed him a SB 4 groove crank pulley and he found a SB 2 groove water pump pulley and with a 1/4" spacer he got them to line up. But it seemed like he was going to have to build a custom alt mount to get everything done. And because of how close his aluminum radiator ends up, he can't get the fan bolts out without removing the radiator. I told him to use the single groove crank pulley I had and order the water pump pulley from 440Source and be done with it. Too much futzing around when the parts are available.

There was a similar setup on 67 or 68 Dart at the Spokane Speed and Custom show a couple of weeks ago. 4 groove crank pulley with a 2 groove water pump pulley and 3 spacers to get the alt to line up. No idea where he got the water pump pulley, but I would bet it was a SB one.
 
Kent mosby said:
This does not fit. It hits the water pump mount bolts. I have another one on order from ebay. We will see.
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I saw a note on a water pump pulley that 440Source sells that said washers can not be used on the water pump bolts or the pulley will hit. Do you have washers on your water pump bolts and if so would it maybe fix the issue?
 
DionR said:
I saw a note on a water pump pulley that 440Source sells that said washers can not be used on the water pump bolts or the pulley will hit. Do you have washers on your water pump bolts and if so would it maybe fix the issue?
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No washers on them. It is too long and aluminum too thick.
 
There are a few bb water pump pulleys under 6 3/4 inches down to 6 1/4 inches. Also crank pulleys of different sizes. They are getting dam hard to find. The depth of the w/p pulley needs to be approximately 2.75 inches deep. A small block pulley will bolt on but then u have other issues. As stated b4 the bb were almost always under driven. Kim
 
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