Pulley/Belt Orientation Questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SCOTI · 12-06-2002, 01:29 AM

I'm trying to fabricate a pulley system for my big block in my 67 & know that the difference between long & short water pumps is 1.5". I have a long & short water pump on hand to help w/measurements. I know Moroso makes a spacer for short pumps to equal the overall dimensions of the long pump & I can only guess it is approx 1.5" (that's also the dimension in the summit catalog).

Ok, here's where the confusion starts (at least for me) . . . I'm using a 2-groove LWP, crank pulley & a 2-groove SWP, water pump pulley.
Now simple math equates to spacing the short water pump out the 1.5" required to equal the long water pump right? But, when I space the short water pump/pulley out I only need 1" to align the crank & water pump pulleys. I'm using 3/8 alum tubing that I've bent around the pulleys to verify/check the alignment so it should be close enough.

Anyone have a logical explanation for this? My best guess is the factory set-ups overlapped waterpump & crank pullies but I'm open to suggestions. Any SWP or LWP big block guys out there that can give me some assistance?

red71cheyenne · 12-06-2002, 11:24 AM

I can't answer your questions, but I can pose a new one. Why are there two different water pumps? What are you avoiding by putting on the short versus the long one? I'm having belt alignment problems too, and don't know the difference. I have both laying around and thought about putting each one on to see if it will help line up the belts. Jeff.

guitarman · 12-06-2002, 11:30 AM

red71cheyenne
Good logical approach.

SCOTI · 12-06-2002, 12:15 PM

red71cheyenne, the reason for using parts from both is space limitations.

My plan is to use low mount accessories (alt.,a/c) that require the short water pump. However, when installed in this location, the a/c compressor hits the center-link so that's not good.

When I swapped to the long water pump, no clearance probs w/the center-link, but . . . the outlet of the water pump is a much steeper angle & interferes w/the lower radiator hose. There isn't enough room for a 45 or 90deg bend w/the fabbed lower hose I'm making, so definitely no room for any bend in a stock type hose.

Soooo, I need the spacing of the LWP but the outlet placement of the SWP. I've accumulated several pulley combos to try & came up w/using the LWP crank pulley ( for the spacing needed), & spacing out the short water pump ( getting the proper outlet angle). Everything was moving right along & then I realized the water pump only required being spaced 1" (not the 1.5" difference of the LWP vs SWP) & this got me overthinking everything. I figure it's better to ask for insight before I lose my mind.

red71cheyenne · 12-06-2002, 12:31 PM

Yeah, compared to yours my problems are minor. I'm just tired of hearing the belts moving. They are very noisy. They work alright, just noisy. I think when I'm on leave, I'll put the short pump on and see if this takes care of it. If I can find any time outside of the "honey do" list that is. Good luck, Jeff.

SCOTI · 12-06-2002, 12:49 PM

You might just need to space the pulleys. Moroso makes aluminum spacers for the water pump pulleys in 1/16 & 1/8" thickness #MOR-64035 thru Summit Racing for just 6.95$ + shipping.

I think what I'll do is order the final pulleys I plan to use so I have definite pulley locations & work from there. I have heard alot about production variances between different manufacurers on pulleys & what I'm using now is a combo of new aftermarket chrome & original sm/big block pulleys so that could account for some of the difference.
This project has been ongoing for 13yrs so it's not like I can't wait a little longer.

12-06-2002, 01:29 AM	#1
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,031	Pulley/Belt Orientation Questions I'm trying to fabricate a pulley system for my big block in my 67 & know that the difference between long & short water pumps is 1.5". I have a long & short water pump on hand to help w/measurements. I know Moroso makes a spacer for short pumps to equal the overall dimensions of the long pump & I can only guess it is approx 1.5" (that's also the dimension in the summit catalog). Ok, here's where the confusion starts (at least for me) . . . I'm using a 2-groove LWP, crank pulley & a 2-groove SWP, water pump pulley. Now simple math equates to spacing the short water pump out the 1.5" required to equal the long water pump right? But, when I space the short water pump/pulley out I only need 1" to align the crank & water pump pulleys. I'm using 3/8 alum tubing that I've bent around the pulleys to verify/check the alignment so it should be close enough. Anyone have a logical explanation for this? My best guess is the factory set-ups overlapped waterpump & crank pullies but I'm open to suggestions. Any SWP or LWP big block guys out there that can give me some assistance? __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

12-06-2002, 11:24 AM	#2
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	I can't answer your questions, but I can pose a new one. Why are there two different water pumps? What are you avoiding by putting on the short versus the long one? I'm having belt alignment problems too, and don't know the difference. I have both laying around and thought about putting each one on to see if it will help line up the belts. Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

12-06-2002, 11:30 AM	#3
guitarman Do it well or don't do it Join Date: Apr 2002 Location: Georgia Posts: 457	red71cheyenne Good logical approach. __________________ Try to be the person your dog thinks you are. Excellent paint and body site: http://www.autobody101.com/ Visit my Web Site http://home.attbi.com/~agfosteriii

12-06-2002, 12:15 PM	#4
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,031	red71cheyenne, the reason for using parts from both is space limitations. My plan is to use low mount accessories (alt.,a/c) that require the short water pump. However, when installed in this location, the a/c compressor hits the center-link so that's not good. When I swapped to the long water pump, no clearance probs w/the center-link, but . . . the outlet of the water pump is a much steeper angle & interferes w/the lower radiator hose. There isn't enough room for a 45 or 90deg bend w/the fabbed lower hose I'm making, so definitely no room for any bend in a stock type hose. Soooo, I need the spacing of the LWP but the outlet placement of the SWP. I've accumulated several pulley combos to try & came up w/using the LWP crank pulley ( for the spacing needed), & spacing out the short water pump ( getting the proper outlet angle). Everything was moving right along & then I realized the water pump only required being spaced 1" (not the 1.5" difference of the LWP vs SWP) & this got me overthinking everything. I figure it's better to ask for insight before I lose my mind. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*

12-06-2002, 12:31 PM	#5
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	Yeah, compared to yours my problems are minor. I'm just tired of hearing the belts moving. They are very noisy. They work alright, just noisy. I think when I'm on leave, I'll put the short pump on and see if this takes care of it. If I can find any time outside of the "honey do" list that is. Good luck, Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

12-06-2002, 12:49 PM	#6
SCOTI Registered User Join Date: Apr 2001 Location: DALLAS,TX Posts: 22,031	You might just need to space the pulleys. Moroso makes aluminum spacers for the water pump pulleys in 1/16 & 1/8" thickness #MOR-64035 thru Summit Racing for just 6.95$ + shipping. I think what I'll do is order the final pulleys I plan to use so I have definite pulley locations & work from there. I have heard alot about production variances between different manufacurers on pulleys & what I'm using now is a combo of new aftermarket chrome & original sm/big block pulleys so that could account for some of the difference. This project has been ongoing for 13yrs so it's not like I can't wait a little longer. __________________ 67SWB-B.B.RetroRod 64SWB-Recycle 89CCDually-Driver/Tow Truck 99CCSWB Driver All Fleetsides @rattlecankustoms in IG Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive. It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar..... *Cubic inches is like Indiana Jones with a cheap pistol.*



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