Fitting of 1.8 alternator with 6 groove pulley

[alfamike]

I am working on this car for someone else, & he provided me with an 80 amp alternator listed for a 92-93 Geo Storm with a 1.8 motor. It has a 6 groove pulley rather than the original 4 groove. The invoice lists GM part number 97029986, & the alternator has the following numbers on the data plate: 8970299861 & 100211 8530.

Has anyone successfully fit one of these alternators to their Elan? An archive search turned up some info on alternators with 6 groove pulleys, but there is no actual mention of fitting one without a pulley swap. In my case, a pulley swap is not possible (I tried it) because the new alternator has a larger diameter shaft than the original.

I was able to mount the new alternator in the car, & I was able to install & tension the belt using the 4 grooves closest to the alternator body in order to acheive proper belt alignment. However, I pulled a stupid human trick in that I had the PAS hose in the wrong position, & the only way to remedy the problem was to remove the new alternator I had just mounted.

My concern is the clearance between the 6 groove pulley & the body of the car. It looked a little too close for comfort. However, I also have the right side engine mount off because I'm doing a cambelt/water pump job on the car, & I was not able to mock up the mount & properly position the engine because of the aforementioned PAS hose.

Therefore, before I reposition the PAS hose & go through this whole exercise again, I was hoping that someone could definitively confirm whether or not the 6 groove pulley has sufficient clearance from the body of the car.

Thanks,

Michael Keith
Houston, TX, USA

[ailwyn]

The only one I know of in the UK so far is Sy, and he had the pulley swapped from his old alternator, although IIRC five or so made it over here, so maybe someone else has done it with the 6 groove pulley?

[nitroman]

Alfamike, lots of people have switched to the higher-output 92-93 Isuzu alternator, SyV for one. Running the belt on the 1st-four grooves should be fine as I've seen the latter zuzus this way stock. Apparently not all had the need for 6-grooves... whatever accessory brought it on.

The alternator body-size should fit fine, as it's in use with 1/2-dozen or so folks. They even did a group-buy on that alt. to Europe I believe, for the purpose of having a more powerful alt. (yes, I know its only 5 or 10 amps more)

-Matt in JAX-

[alfamike]

I decided to go ahead & answer my own question, & yes, the 6 groove pulley does hit the body of the car. Where the upper control arm mounts to the frame, there is a lip that extends about 1/2" inward from the main part of the frame, & the larger pulley rests against that lip. I thought about taking a side cutter to that lip, but it looks like there is a critical weld in that spot.

I'll have to see what the owner wants to do, but I sure am getting good at R&R'ing that alternator.

[Elanlover]

Pretty sure I read that the pully wheel was changed and that is was fairly straightforward to do in that it did fit the larger alternator.

[alfamike]

With that alternator that I was provided with, swapping the pulleys was not a possibility because it has a larger diameter shaft than the original.

Anyway, I've sourced a 75 amp alternator with the correct pulley.

[Sy V]

All I can say is that my 80amp and the OEM alternator had identical shafts. I didn't have the tools to remove the pulley wheel so I sent it away, but the guy that did it said it was a breeze.

[Elanlover]

With that alternator that I was provided with, swapping the pulleys was not a possibility because it has a larger diameter shaft than the original.

Anyway, I've sourced a 75 amp alternator with the correct pulley.

What and where if I could ask please. Thanks.

[alfamike]

Sy, I read the post on this topic (the 12 page one from a while back), & the part number for the 80A alternator referenced in the group buy resultant from that post is different from the one I was provided with. The one I received referenced a GM part number of 97029986 on the invoice. I figure that to be the difference.

Elanlover, I found the one I'm going to use with the Beck/Arnley part number 1860545. That part number should cross over to other manufactures as well. It has a 4 groove pulley & is rated at 75A. I think at one point, there was probably a 60A & a 75A with the same body, pulley, etc. However, the aftermarket probably superceded the 60A with the 75A.