View Full Version : Chevy Alternator backwards?


INVISIBLEKID
05-03-2009, 02:48 PM
Hey all- Here's a silly question- I've got a chevy alternator,SI,thats been turned into a 1 wire.Because of space limitations,and I don't want a belt that's 14 feet long,the easiest way(not really) is to mount it backwards down close to the ballancer. I've read some info about making sure to lock-tite the nut in front,and it will be right behind the electric fan,but was wondering about the fan on the alt itself? Dirrectional blades? I would think that it should charge either way,but before I start making brackets and getting all crazy,just wanted to get a little reassurance,cause i'll be pissed to do this for nothing. Anyone? Have you done this? Results?
Thanks-Kid:confused:

j-dogg
05-03-2009, 02:58 PM
alternators don't care which way they turn.

onlychevrolets
05-03-2009, 03:38 PM
alternators don't care which way they turn.

This is true but the fan does. My 671 huffed 355 in a S-10 had the alt. mounted backward and I never had any trouble out of it.

Stevie G
05-03-2009, 07:10 PM
If the fan on the alternator becomes a problem, consider a marine unit for a reverse rotation engine, or the cooling fan from one at least.
Just a thought.

Andy
05-03-2009, 07:35 PM
I had one mounted backwards in a Jag. It did fine for 15 years. A/C and all. I tried to drive it with a dead battery and have the alternator charge it. It fried the alt.

fitzee
05-03-2009, 08:36 PM
GM Alternator from the V8 cars will give you trouble. we had a TR6 here that ran into much the same trouble. Turned it around and mounted it backwards and it worked as long as you did not buzz the engine. It keep blowing them at high RPM. found out that the fan on the alternator is for cooling and the back of them don`t let air pass through them. how we fixed it was we use a FWD alterator from a sprint.they are open on both the front and the back which lets them cool better.

INVISIBLEKID
05-03-2009, 11:00 PM
Lots of different info- but common is that it will charge backwards.Suspected that in the begining,but wanted pro's and con's. The cooling issue has me somewhat concerned,but this will only see high rpm sometimes and the electric fan will be blowing right into it. Gonna give it a shot and see.Nothing really to loose..........Thanks all.

Stevie G
05-04-2009, 08:56 AM
If cooling becomes an issue, switch to a reverse water pump and run the pump off the backside of the serpentine/ blower drive. Then, run a v-belt from the pump to the alternator.

Model A Vette
05-04-2009, 02:38 PM
The alternator on a '65-'69 Corvair turns in the opposite direction from a "normal" alternator. It has a reversed fan AND a locking nut to keep it from getting a loose pulley.

walrus
05-04-2009, 03:39 PM
Interesting post , did not know , but suspected you could run the alternator either way , Does the alternator fan work both ways also??,,

Model A Vette
05-04-2009, 04:43 PM
The alternator will work in either direction but the fan has to be matched to the direction of rotation so that it blow air INTO the alternator.

35mastr
05-04-2009, 05:05 PM
Instead of running it backwards. Why not just get a small Toyota (http://images.search.yahoo.com/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fs earch%2Fimages%3Fp%3Dsmall%2Btoyota%2Balternator%2 6ni%3D20%26ei%3DUTF-8%26fr%3Db1ie7%26fr2%3Dtab-web%26xargs%3D0%26pstart%3D1%26b%3D1&w=400&h=266&imgurl=www.arengineering.com%2Finstructsheet%2FDsc _0583_400.jpg&rurl=http%3A%2F%2Fwww.arengineering.com%2Finstruct sheet%2FEarly_SB_Kit.html&size=26k&name=Dsc_0583_400.jpg&p=small+toyota+alternator&oid=057ea31acd16705a&no=1&tt=23&b=1&ni=20&sigr=11sf4qe2u&sigi=11kk13a5i&sigb=13vd3ucff)one and run it the right way?

onlychevrolets
05-04-2009, 05:49 PM
Interesting post , did not know , but suspected you could run the alternator either way , Does the alternator fan work both ways also??,,


no...

INVISIBLEKID
05-04-2009, 07:04 PM
Here's the deal....in the pic,i'm running 461 casting "fuellie" heads that do not have holes for mounting anything,nor does the intake.Interference comes into play with the radiator hose and the lower k-member in the car or I just would've made a bracket to mount it down low,and spin it normally.But,with the space issues,this was the simplest,easiest route. I knew it would charge either way,but the alt fan and nut was a concern. I think that the tightness of the nut,plus a dab of loctite,will solve this problem. Also as pictured,the cooling holes in the case of the alt as it's possitioned,are right in front of the cooling fan.I think I'll make a little air scoop and dirrect the air from the fan right into the alt. If you've ever had a newer SI alt,(newer chevy) they get pretty warm to begin with.I think I'de be doing myself a favor,and the alt.I have what I have,and will make it work.I think it will be ok. I'll have to see......


Nobody said Hot-Rodding was easy!

Stevie G
05-04-2009, 08:19 PM
The alternator on a '65-'69 Corvair turns in the opposite direction from a "normal" alternator. It has a reversed fan AND a locking nut to keep it from getting a loose pulley.

Now that there is one for the archives.
Note to self, remember that.

36-3window
05-04-2009, 08:47 PM
Now that there is one for the archives.
Note to self, remember that.

i didn't know that either. but, i assume it will require an external regulator....not that there is anything really wrong with that

CShroom
05-04-2009, 09:13 PM
It is pretty common for the Corvair people to use a stock 1 wire with the reversed fan. So if you can get a Corvair Alternator fan from Clark's Corvair or Corvair Underground, you'll be golden. Or if you are real lucky, you can find a 66-9 ( IIRC) Corvair in junkyard and pull one from it.

low budget
05-04-2009, 09:55 PM
How about this?:cool:

plym49
05-04-2009, 10:05 PM
Some older Ferrari's mount the alternator and other devices backwards.

beernut
05-04-2009, 10:08 PM
is that a dist.driven alt,off the tach drive?

69fury
05-04-2009, 10:28 PM
How about this?:cool:

DUDE! Details and pics on THAT setup, man! That's slick.

low budget
05-04-2009, 10:34 PM
Sorry I cant remember the thread on here I saved that pic off of, but yeah it looks pretty slick.
I just assumed it ran off the back of a smaller pully on the front of the engine with a cable set up like a speedometer or a weedeater etc.only heavier built???

8flat
05-04-2009, 10:58 PM
Sorry I cant remember the thread on here I saved that pic off of, but yeah it looks pretty slick.
I just assumed it ran off the back of a smaller pully on the front of the engine with a cable set up like a speedometer or a weedeater etc.only heavier built???

I remember the same thing....cable driven. It was a while back but I thought someone also made one that was driven off the flywheel?

36-3window
05-04-2009, 11:20 PM
i remember the thread on that cable drive alternator , i think that setup used a cable from a concrete vibrator?

8flat
05-05-2009, 09:14 AM
Hollywood Hot Rods built one, slick setup:
here (http://www.jalopyjournal.com/forum/showthread.php?t=337080&highlight=cable+drive+alternator)

Ideas for driveline-connected alternators:
here (http://www.jalopyjournal.com/forum/showthread.php?t=307116&highlight=cable+drive+alternator)

TexasHardcore
08-31-2009, 11:39 PM
delete