Cheap and easy 140amp alternator solution for hot-air cars.

[TType84]

The hotairs use a small case alt, and there isnt really an easily accessable replacement that you can acquire on a whim incase of failure.

DURALAST 94 AMP DL7294-6 LLT $99.99

AutoZone's only option... a special order part as well.

I stumbled upon a solution to this problem years ago, some of you may already know about this, but incase you dont, I think its a pretty worthy and inexpensive modification.

Its simple... the stock hotair ac/alt bracket? TOSS IT!

Go to the nearest u-pull-it and snag a bracket off a n/a 3.8 car. The trick is that the bracket is wider and accepts the more common 6" case alternators.

Now that you have a wider bracket, what should you do with it, you ask?

Stroll on up to your local parts store and pick up a stock LT1 alternator. To keep the confusion level low for the average autozone worker, ask for an alternator for a 97 camaro with a V8:

DURALAST 140 AMP DL1429-6-7 LLT $99.99

This is a NORMAL STOCK part and I've yet to have a problem getting a new one on exchange ever.

Same price, more amperage, always in stock.

Of course you will need to snip off the factory voltage regulator plug and replace it with one that fits, and this would be a PITA except if you stroll over to the help! aisle in the store you will find a pigtail that snaps right in. connect the smaller dia brown wire to the wire coming out of your engine harness and you are good to go.

The factory alt->intake bracket still fits as well.

And yes, I know you can just have a local alternator shop wind your stock alternator into a higher amperage design, thats great. I did this too, and a year later when the alternator died I had the biggest headache trying to get them to honor my warranty. With a big chain parts store, you walk in with the old one, swap it, and leave. easy.


This is a win-win situation. :biggrin:

 

[novaderrik]

what years and models of cars would you get the "big" bracket from?
the reason i ask, is because every NA 3.8 car i've looked at in the boneyard from the mid 80's has the same bracket as my Regal.
perhaps a fully loaded "big" car with a 4.1 in it- like a Lesabre or something might have a bigger case "HD" alternator in it, i guess.
the high amp solution i found for my Regal was a CS 120 alternator out of (i think) a 3.1 powered grand Prix. it puts out 120 amps and it has a nice, small case. but the mounting holes are offset, so i made a simple adapter bracket that allowed me to use the offset mount alternator in the stock bracket on my car. i tried a "straight across" CS120 alternator from my brother's 88 Grand Am, but it was too small for the brackets by about 1/4" or so, so i put in the offset alternator.
here is a pic- the bracket looks kind of homely, as i've been too lazy to take it off, round the edges, and paint it black..
and what is the part # for the "Help" plug you mentioned? i'd imagine it's cheaper than the $30 plug i got from GM when i did the swap.

 

[Jerryl]

The hotairs use a small case alt, and there isnt really an easily accessable replacement that you can acquire on a whim incase of failure.

DURALAST 94 AMP DL7294-6 LLT $99.99

AutoZone's only option... a special order part as well.

I stumbled upon a solution to this problem years ago, some of you may already know about this, but incase you dont, I think its a pretty worthy and inexpensive modification.

Its simple... the stock hotair ac/alt bracket? TOSS IT!

Go to the nearest u-pull-it and snag a bracket off a n/a 3.8 car. The trick is that the bracket is wider and accepts the more common 6" case alternators.

Now that you have a wider bracket, what should you do with it, you ask?

Stroll on up to your local parts store and pick up a stock LT1 alternator. To keep the confusion level low for the average autozone worker, ask for an alternator for a 97 camaro with a V8:

DURALAST 140 AMP DL1429-6-7 LLT $99.99

This is a NORMAL STOCK part and I've yet to have a problem getting a new one on exchange ever.

Same price, more amperage, always in stock.

Of course you will need to snip off the factory voltage regulator plug and replace it with one that fits, and this would be a PITA except if you stroll over to the help! aisle in the store you will find a pigtail that snaps right in. connect the smaller dia brown wire to the wire coming out of your engine harness and you are good to go.

The factory alt->intake bracket still fits as well.

And yes, I know you can just have a local alternator shop wind your stock alternator into a higher amperage design, thats great. I did this too, and a year later when the alternator died I had the biggest headache trying to get them to honor my warranty. With a big chain parts store, you walk in with the old one, swap it, and leave. easy.


This is a win-win situation. :biggrin:

Excellent description!
Can you post a pic of the set-up?

 

[TType84]

I will grab the part number on my lunch break. I snagged one off a random 3.8 car at a boneyard after the AC portion of my stocker snapped. The brackets look 100% the same to the naked eye, only when I got home and tried to put my stock alternator on, came the WTF!?!?!!? moment.

The bigger brackets have a casting "nubbin" at the very top where the intake brace bolts on, it is not flat.

the larger alt and the nubbin is visible in this pic

the alt, to repeat is 6" diameter. it is approx 8" from ear to ear.

EDIT: most of these alternators do not come from the factory clocked correctly. You are going to want the post on the back of the alternator and the plug for the voltage regulator as close to the drivers side of the vehicle as possible to keep them away from the up-pipe. I have been told that there is a certain torque procedure when reclocking an alternator case, however I have never had a problem just using the star pattern with a dab of loctite.

 

[turbofish38]

The NA 3.8 cars use 2 different series of alternators. I cant remember my terminology but it is either the 10SI or 12SI that is the larger on these cars. I do know the 94amp unit that is standard on the hot air is optional on the NA if that helps. Somewhere I have some numbers out of an old Delco catalog on the 12SI 120 upgrade for these cars.

I also have a 120amp unit I snagged off of a 88-92 vintage Cadillac 4.1/4.5/4.9 that looks like it will fit to but I haven't gotten around to looking. If it does than you would have to swap the pulleys and the wire connector which is no big deal. I'll post some pictures and part numbers when I get it done.

 

[6SENSE]

There is info on this lurking somewhere around here, using the search function I did this a year or so ago and I know I wasnt the first. Sorry Jerryl I guess I forgot to metion this upgrade suggestion on your thread awhile back.
Ive been using a 120amp alt (came on a ton of FWD 3800 motors) that I found new in the junk yard where I snatched the bracket off of a NA3.8 Cutlass. I have a 140 amp spare alternator for my '95 9C1/LT1 CapriceSS sitting around but havent really seen a need for it yet in the TR.

 

[TType84]

There is info on this lurking somewhere around here, using the search function

i'm sure the search function on this board goes back to 1998.

this is info most hotair boys do not have. figured it would be useful to 99% of the people that have not figured this out by chance. if not... no biggie.. not a big deal to me... figured a lot of people do not know this.. but.. its all good.

 

[6SENSE]

No insult intended

i'm sure the search function on this board goes back to 1998.

this is info most hotair boys do not have. figured it would be useful to 99% of the people that have not figured this out by chance. if not... no biggie.. not a big deal to me... figured a lot of people do not know this.. but.. its all good.

I agree, good thinking. It was late and I think I actually misread [or missed] part of your first post stating that this was something from years ago :redface:


P.S. our oe alts are SI and the newer post '86 alts are CS. The SI that wh have originally are the same as the SBC etc so if you want you can get one of those hi amp ones that are out there, but much more expensive. I like the conversion, less expensive and you can use oe alts w/ lifetime warranties from places like AZ

 

[TType84]

gay! i cant edit my original post. oh well.

http://www.upshizzle.com/usercp/files/18/alternator01.jpg
http://www.upshizzle.com/usercp/files/18/alternator02.jpg

tell me if those links work. and yes i know my engine bay is DIRTY

the correct bracket is p/n: 255031034

 

[esinger]

I'm getting ready to do the alternator change out this weekend.

I found the correct pigtail/plug at Autozone and it's has a part number of 85854 and it's description is "Voltage Regulator Module Socket GM". I think it was $6.97

If I'm reading this posting correctly, I should clip off the red and black wires that come with the plug and use the brown wire for the wire to the engine harness that the current alternator is connected to. Is this correct?

I also acquired 2 extra 255031034 brackets. So if anyone is looking for one let me know.

 

[Jerryl]

I'm getting ready to do the alternator change out this weekend.

I found the correct pigtail/plug at Autozone and it's has a part number of 85854 and it's description is "Voltage Regulator Module Socket GM". I think it was $6.97

If I'm reading this posting correctly, I should clip off the red and black wires that come with the plug and use the brown wire for the wire to the engine harness that the current alternator is connected to. Is this correct?

I also acquired 2 extra 255031034 brackets. So if anyone is looking for one let me know.

One of these days. I may do this as well.
Meanwhile I am interested in a bracket. PM me please.

 

[turbogimp]

sticky?

This some great info! this info should become a sticky or part of one. I have owned my car for 4-5 years now and would have done this a long time ago. even though my alt is new Im going to do this in the spring. Thnaks alot!

 

[6 to go]

Eric, I sent an e mail on the brackets. Thanks.

 

[esinger]

Spare Brackets

I've been contacted by three people so far on the spare brackets I have.

6_to_go, you're the third to contact me, so I'm going to have to wait for the decision of the two before you before I could sell you one.

Thanks

 

[turbogimp]

hey TType84 did you have to change the pully on the bigger alt?

 

[turbofish38]

Here is how I did the big alternator on one of my hot airs. And I need to do this to another one here shortly and I plan on taking pictures so you can see what the differences in the brackets are so you can eyeball one in the boneyard with out having to look for the casting number. BTW that casting that Eric provided should be 25503134 and was used on all 1981-1987 RWD Buick V-6's. I find them on a lot of the 4.1 cars and it appears they may have been part of the guage option on the 81-83 cars. Look for the voltage gauge on the right rear corner of the cluster and its a sure bet that it has the bracket. I've been sourcing out my parts used and the best car to get that 120 amp unit off of is the 86-91 Cadillac FWD with the 4.1/4.5/4.9 V-8. Look for the code K09 on the SPID label that is on the spare tire cover in the trunk. Its the only alternator that was available in those years so it should have it unless somebody stuck one of the smaller 108 amps on it. And the 92-93 Caddys with the 4.9 used the bigger 140 amp job that will work too. Now you're saying those are serpentine belts, how are they going to work with a V-belt. Simple, you can swap the pulleys. Just use your old pulley and spacers. Use the fan that came on the donor alt as it is the more efficient hi-flow style.Use an air impact the loosen the nut. You cant do it with hand tools. You will need to re-clock this one too. Now I see everybody is splicing on the correct connector. Its not needed. Delco makes an adapter that is a plug and play. Use Delco part number 8078. Go to acdelco.com and they have a picture of it there. I think thats it. And for those of you who are like me and pack rat spare parts. The 120 amp unit from an 86-87 IC car will work along with the 140 amp from any LT1.Just swap the pulleys.

 

[esinger]

Red Wire

Hi Eric F.

I noticed the plug and play adapter seems to use the red wire as well. On the plug I bought from Autozone it has red, black and brown wires. I'm going to splice the brown wire into the engine harness as TType84 mentioned, but should I go ahead and run the red wire to the positive on the back of the new alternator like the original plug does? I also guess I should just eliminate the black wire.

Thanks

 

[esinger]

Finished the Alternator conversion

Well, just finished up the alternator conversion. I needed to add two things that I wasn't expecting to my setup.

The first was the positive post on the rear of the alternator was bigger than the original alternator, so I had to strip off the ring connectors on all the wires that connected to that post and go to NAPA (just was local to me) and bought some larger ring connectors to fit over the new positive post. I needed one ring connector for a large wire (guessing about 6 to 8 gauge) and 2 ring connectors for 10 to 12 gauge wires.

The next unexpected surprise was the top bolt that mounts the alternator to the bracket was too small and too short. So I went to Home Depot and bought a 3/8" X 2 1/2" bolt, a set of 3/8" washers and a 3/8" nut.

Re-clocking the alternator was easy, I spinned it 180 degrees from it original position. Since I didn't have an air compressor and impact wrench, I had to take both alternators over to Merchants Tire and Auto (Local to me also) and they switch the pulleys for free.

I'm currently getting some belt screech, but with some minor help from a friend I'll should be able to tighten the belt by repositioning the alternator.

 

[GN84Turbo]

pictures anyone?? im interested in how this looks installed, picture links above are broken.

 

[esinger]

I'll try to post some pictures today of my install. I can also post a side by side difference of the two brackets, since I stillhave the original bracket and a spare N/A 3.8 bracket.