Serpentine belt swap

Doober

Moderator
Jun 2, 2003
14,704
1
38
Catalina, AZ
www.cardomain.com
I've gotten quite a few PMs over the past month or two about serpentine conversions, and figured I'd make a thread for it. One of the most commonly available setups is off the late '80s-early '90s GM full size and S-Series trucks - must be a 4.3 if from an S-truck, won't matter with a full size because brackets are the same. Be sure to get the aluminum bracketry, the steel 'horseshoe' design (early serpentine) may cause steering gear interference (round cover gears should clear ok, the pulley may contact the right rear corner of the 4-bolt cover box - looking at it from the driver's seat).
DSC00451.jpg


A/C: If you come across one with an air pump, don't fret, you can leave it out, especially if you're not using a/c. You'll also notice the a/c-bypass idler pulley, these are available from Autozone, etc. for somewhere around $35 if you don't plan to use a/c, or it's not currently in the budget.
http://www.autozone.com/autozone/parts/Motormite-A-C-Compressor-Bypass-Pulley/1993-GMC-K1500-1-2ton-Sub-4WD/_/N-izsa7Z91tb7?counter=0&filterByKeyWord=pulley&fromString=search&itemIdentifier=593937_0_0_
4


If you do have a/c or plan to use it, you'll notice there is a boss just below where the compressor would go, this is for an idler pulley to ensure more pulley contact with the belt. Mine didn't have one to start with, but I believe this is the one required:
http://www.autozone.com/autozone/parts/Duralast-Idler-Pulley/1993-GMC-K1500-1-2ton-Sub-4WD/_/N-izsa7Z8gd4q?counter=0&filterByKeyWord=pulley&fromString=search&itemIdentifier=634072_0_0_5281
4

It's simply listed as an 'idler' pulley, and the routing will simply look like this:
pulleys.jpg


Alternator: My setup is from a '94 which uses the newer style (internal fan) alternator, I'm not 100% sure if this bracket interchanges with the slightly older SI alternators. Also be sure to wire either a 10-ohm, 25-watt resistor, or keep the alternator/battery bulb for your dash wired in line with the brown wire that plugs into the rear of the alternator, otherwise you risk burning it up (a faulty bulb/connection here can also cause the alternator to not work to start with, causing you to chase your tail).

Water pump: Get a reverse-rotation pump for a 4.3 S-truck, or one of the '88-'95 trucks, later years use a different type of snout (the pulley bolts over a threaded snout like normal, and the radiator fan threads onto the pump snout... not to mention they're a lot more expensive than the '88-'95 pumps).

More to come... probably. People have swapped serpentine setups from other vehicles (Camaro/Firebird/Caprice/Roadmaster/etc.) as well, so if you have info on those cars, feel free to post!
 

LS6 Tommy

MalibuRacing Junkie
May 15, 2004
15,847
1
38
North Jersey
1980PontiacWagon said:
any idea on what cars to look at when trying to find a serpentine set up for a big block chevy??
Thanks.


GM sells a kit that's probably cheaper than trying to piece a setup together.


http://www.jegs.com/i/GM-Performance/809/19172805K/10002/-1?parentProductId=752514

I hate to give Jeg's business, but their price was over $80.00 cheaper than Summit...

Tommy
 

shvrolay

Dragway Regular
1980PontiacWagon said:
any idea on what cars to look at when trying to find a serpentine set up for a big block chevy??
Thanks.

Doesn't someone make brackets to adapt a SB set-up to a BB?
 

psychomotors

Dragway Regular
Mar 31, 2011
896
0
0
Bonne Terre, Mo
I might suggest that if you are using salvage yard parts, that you replace ALL idlers , tensioners and A/C clutch with new parts. In the last 4 years, I have lost 3 belts because of seized pulleys on my Mercury Mountaineer. I wouldn't have a serpentine setup on anything I own! You lose the belt, you lose everything and are stranded till you can get it fixed. JMHO
 

bbc-olds

Frequent Racer
Jun 7, 2008
542
2
18
Malin OR
These guys made the conversion kit, http://www.kwikperf.com/bbc_serp_kit.html Had one and they work good.
 

383S10

Frequent Racer
Feb 29, 2004
581
0
0
Huntsville, AL
This one came off a full size truck and is THE WRONG ONE TO GET FOR A CAR .....it places the power steering pump up against the driverside frame rail.....it wont work please benefit from my mistake.......
IMG00026-20100419-1835.jpg


Now these two pieces came off a 89 V-6 Blazer.....this is what you want on your sbc motor....these are photo aids to help reinforce Doober's point on his thread.........
utf-8BSU1HMDAwMTktMjAxMDA0MTgtMTQzNC5qcGc.jpg

utf-8BSU1HMDAwMjEtMjAxMDA0MTgtMTQzNS5qcGc.jpg

utf-8BSU1HMDAwMzYtMjAxMDA0MjgtMTUwMS5qcGc.jpg
 

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