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Need alternator for the 85-86 hybrid belt setup:

vandelay industries

vandelay industries

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My engine is based on an 85-86 (although the truck is not). i'm using all the included pulleys etc. Thus i have a ribbed serpentine belt for the water pump and alternator. And conventional V-belt for everything else.

The ribbed belt is i believe 5 rib? And the pulleys i believe are 4 grove?

1) AC Delco and Remy both list alternators with a V-belt for this application.

2) All the parts stores pretty much also list alternators with V-belts for this application (Even though if you look up alternator BELT on their websites, it lists the ribbed belt..............)

Can someone come up with a workable part #. The plug is in the 12:00 position and i would like to keep it under 78amps, 63 preferable.

i know i could switch pulleys but i don't have the tools/ability to do so now. So i would prefer just to keep it simple with a bolt on part.
 
I don't know if it will help, but I parted an '87 K10 that had that alternator on it. No A/C.
 
I had a 305 from an '86 G-10 van in my '79 Bonanza pickup and that engine had the serpentine alternator belt only,the other things were v-belt driven still...
I had to use the belt listed for that model & engine,the # was a Gates KO50435,it had no A/C or air pump,the belt listings were quite "lengthy",a lot of various choices,I was lucky the OEM belt still had legible numbers on it to match up..

I never had to get an alternator for that engine,if I did I probably would have had to use the '87 truck listings,it does seem like most catalogs still list a v-belt alternator for engines '86 and lower,which is wrong..

Most parts stores can and will zip off your original pulley and re-install it on a new or rebuilt alternator if they have one that is correct ,other than the pulley not being the same..rather than lose a sale..I had to do it several times a day sometimes when I worked parts counters..
 
Some of the cars ended up with this setup too. I want to think my "semi-serpentine" setup was out of an '85 Monte SS. It may have been later.

The pulley's are interchangeable, the body of the 12Si alternator can be "clocked" in four positions, generally I believe all the 12SI's are interchangeable for that reason. I'm sure there are exceptions, but they are a pretty universal fit.

Any reason to go with the smaller alternator? The larger alternator should do better under heavy load at idle (which the 12SI's are bad at handling in the first place), if the price is the same, and it's a bolt in swap, I'd not worry about it.
 
dyeager535 said:
Some of the cars ended up with this setup too. I want to think my "semi-serpentine" setup was out of an '85 Monte SS. It may have been later.

The pulley's are interchangeable, the body of the 12Si alternator can be "clocked" in four positions, generally I believe all the 12SI's are interchangeable for that reason. I'm sure there are exceptions, but they are a pretty universal fit.

Any reason to go with the smaller alternator? The larger alternator should do better under heavy load at idle (which the 12SI's are bad at handling in the first place), if the price is the same, and it's a bolt in swap, I'd not worry about it.
Click to expand...

Because i don't want swap pulleys and upgrade the charge wire that connects to the B+ terminal on the alt. i did think about it more an realized i could probably borrow an air impact and compressor from someone at work (does tank size affect how long you can use the tool vs. power output of the tool? i don't know anything about air tools).

But really i'm very short on time these days, so i basically copped out.
 
Tank size affects how long you can use the tool, but compressor power and airflow matters as well. Tools that require a lot of air (measured in SCFM) can't run long without stopping to let the compressor recover if you're using a less powerful unit. To upgrade alternator wiring, you can pretty easily run a larger gauge wire from the terminal directly to the battery.
 
vandelay industries said:
Because i don't want swap pulleys and upgrade the charge wire that connects to the B+ terminal on the alt. i did think about it more an realized i could probably borrow an air impact and compressor from someone at work (does tank size affect how long you can use the tool vs. power output of the tool? i don't know anything about air tools).

But really i'm very short on time these days, so i basically copped out.
Click to expand...

GM didn't change the charge wire ever, AFAIK. Same size whether the truck had a 37A or 78A alternator.

Pulley swapping is pretty easy, I know I took mine apart without the assistance of air. I'm sure it would have been easier with, but I didn't have the luxury at that time.
 
That belt setup came around in '85, and I think '84 in cars. GM went full serpentine in '88 EXCEPT for the squarebody trucks (they switched in '89). They started putting the CS130 alternator in cars in '87 and maybe trucks too. My '88 Burb came stock with the CS 130.

Also, I've changed a lot of alternator pulleys without an impact. It usually involves a pipe wrench to hold the pulley, a socket and breaker bar on the nut, and a hammer to smack the breaker bar. The sudden hit helps to loosen the nut without the shaft just spinning in the pulley.
 
There is also an allen head "hole" in the shaft on the alternator ,you can put an allen wrench in a vise and use a box end wrench to unscrew the nut holding the pulley on--its difficult though,and not always able to be done with success--I've had the hex in the hole strip out a few times trying to do it that way..

Another "might work" method is to try unscrewing the nut while the alternator is mounted and the belt still on it--by clamping the belt tighter around the pulley or using a strap or pipe wrench to hold the pulley still,you may be able to loosen the nut and re-tighten it the same way...

I prefer using an air impact because I've had a pulley decide to come loose doing it "manually"--not fun when you lose ALL the belts going 65 mph!..:eek:..
 
i got an email reply back from REMY, which basically states, "The application requires the customer to re-use his/her old pulley."

However, i ended up getting the AC delco, #321-357 which does have the right pulley.

But, at any rate, i suppose it's time for me to join the 21st century and the rest of society and get some air impact tools............
 
dyeager535 said:
GM didn't change the charge wire ever, AFAIK. Same size whether the truck had a 37A or 78A alternator.

Pulley swapping is pretty easy, I know I took mine apart without the assistance of air. I'm sure it would have been easier with, but I didn't have the luxury at that time.
Click to expand...

Now, about the charge wire: i heard that if you go higher than 78amps, you need to upgrade the charge wire in case the alternator has to charge a dead or nearly dead battery? To at least 8 gauge?
 
i know it's difficult to see, but is this the correct orientation for the brushes---assuming the springs were in? i've had to re-clock the new alternator. This is my first time taking one apart.

And yes, this picture is of the old alternator:
FullSizeRender-1%203_zpsjrbfsyft.jpg
 
NEVERMIND:
When i got the new one apart, the new brushes had the holes that lined up with the hole in the back of the case---so it was self-explanatory at that point.

But the important issue now is the starter sometimes will not want to turn over----which is the reason why i thought i needed a new alternator---because the battery tester was saying poor charging---less than 14volts.

It is still reading that way now, although all the lights seem brighter? The battery itself seems ok, as i tested it all week in another car and the tester says ok.

Do you think it's maybe the starter?
 
An old atimer mechanic taught me when I was young. He said if the battery voltage drops below 10.5 volts while cranking the starter is bad....
 
vandelay industries said:
Now, about the charge wire: i heard that if you go higher than 78amps, you need to upgrade the charge wire in case the alternator has to charge a dead or nearly dead battery? To at least 8 gauge?
Click to expand...

I honestly can't answer that outside of just looking up some random charts online, like this one http://www.powerstream.com/Wire_Size.htm

I'd want to look at what was "stock", and follow GM's lead if I didn't want to upgrade just because. Kind of like the starter wiring. The starters draw somewhere upwards of 250A apparently, the wiring is nowhere near the right diameter for that. But if not pushed too hard, for too long, it will be ok. I wouldn't be surprised if they took the same approach with the alternator wiring. I believe my CS-130 is 105A, I've not upgraded the wiring, but I'm probably never asking it to put out that much either. But since the output at idle is related to maximum output rating (all things equal) a higher output alternator is going to perform better at low RPM's.
 
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