Dual waterpump and 3 crank pulleys - The 1947 - Present Chevrolet & GMC Truck Message Board Network

skokie · 10-22-2004, 02:36 AM

Just curious here as to what the 2nd groove on the water pump and the extra groove on the crank was used for.

Thanks

Russell · 10-22-2004, 02:39 AM

With my 80 -- one belt goes around the alternator, waterpump, and crank, and another belt goes around the power steering pump, waterpump, and crank. I guess GM's thoughts were that if the belt on the alternator or power steering pump blew, they they still had another belt to keep the waterpump spinning so it didn't overheat or something.

orgalmeister · 10-22-2004, 06:51 AM

These are usually for A/C

Tx Firefighter · 10-22-2004, 07:13 AM

Alternator- AC- Power Steering

71Rat · 10-22-2004, 11:36 AM

correct me if i am wrong but if the crank pullies are all the same size and then the water pump has 2 different diamiters on it wont one belt slip or squeel while the other is spinning faster because of the different size? i might be totally wrong but just looking at that it doesnt make sense to me that u would have 2 belts going from the crank at say a 8 inch diamiter and then they go up to say a 7 inch and a 6 inch puley.... something seems as though it would have to give because one will spin fast the the other

maybe someone can shine light onto this for me if i am wrong

Rat

Project1970 · 10-22-2004, 12:04 PM

Yeah, that waterpump pulley doesn't look right to me. That said, on my '70 I actually have a four-groove crank pulley (two pieces). The very front one goes to the power steering pump only. Next to the front is unused. Next one back goes up to the waterpump (front groove) and over to the AC, and the very back one goes to the waterpump (rear groove) and over to the alternator.

10-22-2004, 02:36 AM	#1
skokie Registered User Join Date: Oct 2003 Location: San Jose Ca. Posts: 3,334	Dual waterpump and 3 crank pulleys Just curious here as to what the 2nd groove on the water pump and the extra groove on the crank was used for. Thanks Attached Images __________________ RIP to my son Dylan. 5/17/2002 - 8/18/2018 If you want to know more about rare forms of pediatric cancer or if you want to help fund pediatric cancer research, please check out the website for the non-profit I started. https://slothforpedcancer.org 68 build thread http://67-72chevytrucks.com/vboard/s...d.php?t=223234

10-22-2004, 02:39 AM	#2
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	With my 80 -- one belt goes around the alternator, waterpump, and crank, and another belt goes around the power steering pump, waterpump, and crank. I guess GM's thoughts were that if the belt on the alternator or power steering pump blew, they they still had another belt to keep the waterpump spinning so it didn't overheat or something. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

10-22-2004, 07:13 AM	#4
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Alternator- AC- Power Steering __________________ I'm on the Instagram- @Gearhead_Kevin

10-22-2004, 11:36 AM	#5
71Rat ran out of money Join Date: Apr 2003 Location: northern, NJ Posts: 925	correct me if i am wrong but if the crank pullies are all the same size and then the water pump has 2 different diamiters on it wont one belt slip or squeel while the other is spinning faster because of the different size? i might be totally wrong but just looking at that it doesnt make sense to me that u would have 2 belts going from the crank at say a 8 inch diamiter and then they go up to say a 7 inch and a 6 inch puley.... something seems as though it would have to give because one will spin fast the the other maybe someone can shine light onto this for me if i am wrong Rat __________________ Modify everything, leave nothing alone!~

10-22-2004, 12:04 PM	#6
Project1970 14.1 @ 96MPH Join Date: Jul 2001 Location: Mesa, AZ Posts: 2,811	Yeah, that waterpump pulley doesn't look right to me. That said, on my '70 I actually have a four-groove crank pulley (two pieces). The very front one goes to the power steering pump only. Next to the front is unused. Next one back goes up to the waterpump (front groove) and over to the AC, and the very back one goes to the waterpump (rear groove) and over to the alternator. __________________ Project1970 - LS1 Swap Complete!

10-22-2004, 06:51 AM	#3
orgalmeister Registered User Join Date: Aug 2004 Location: North Carolina Posts: 291	These are usually for A/C



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