Do I need to upgrade my alternator?

68L71

68L71

Well-known member
Joined
May 13, 2008
Messages
747
I have the Dewitt’s setup on my car and I am wondering if I possibly need to add a second alternator or upgrade to one with more output. An electrical genius is always posting about these upgrades on another site. My car has few electrical items, no radio, no wipers, and no heater. I already know that I would not need to ask this question if I had just stuck with the stock setup. I would rather not upgrade if it is not necessary.
 
Yes, absolutely! Triple alternators would be even better. Then you need some ford focus fans, you know because the focus comes with a big honking 572 and if it cools that, it'll cool anything :D
 
Twin_Turbo said:
Yes, absolutely! Triple alternators would be even better. Then you need some ford focus fans, you know because the focus comes with a big honking 572 and if it cools that, it'll cool anything :D
Click to expand...

I have put FORD parts on my Vette to make more HP. The current part is a 5 blade FORD factory flex fan from a truck. Works great. :goodnight:
 
haha...Sears reply now....

Go to a parts house and get a 17SI alt, it's off a '79 Caddy Seville with RWDefogger....rated 108 amps output, only slightly larger diameter but should fit your car without difficulty....it is a direct plug in, assuming you have proper orientation on the rear housing ....if not....you can reorient those reg tabs without problem...

true the Cs140? series has more output and supposed to be reliable, and maybe you can find one at a junkyard for cheep but out of a parts house, you are hurting in the money....

I have a DeWitts Spal fan with just on off relay, DPFI, and C4 blower fan which are the only significant power users at idle.....

:zzz:
 
MYBAD79 said:
68L71 said:
An electrical genius is always posting about these upgrades on another site.
Click to expand...

A wise man once said:

big2bird said:
The virtual slew of sewage pumping thru that site nowadays is astonishing.:smash:
Click to expand...

:lol::lol::lol:
Click to expand...

I should post more of it here, but it gets old after a while....

I go there for mainly poly ticks and OT anymore...

tired of typing the same old replies to whatever....

and seeing so much other stuff making NO sense....
 
mrvette said:
Go to a parts house and get a 17SI alt, it's off a '79 Caddy Seville with RWDefogger....rated 108 amps output, only slightly larger diameter but should fit your car without difficulty....it is a direct plug in, assuming you have proper orientation on the rear housing ....if not....you can reorient those reg tabs without problem...

I have a DeWitts Spal fan with just on off relay, DPFI, and C4 blower fan which are the only significant power users at idle.....

:zzz:
Click to expand...



What about the regulator? I looked up that alternator and one place listed a HD external regulator included. So it is externally regulated, will it work with my current regulator?
 
68L71 said:
mrvette said:
Go to a parts house and get a 17SI alt, it's off a '79 Caddy Seville with RWDefogger....rated 108 amps output, only slightly larger diameter but should fit your car without difficulty....it is a direct plug in, assuming you have proper orientation on the rear housing ....if not....you can reorient those reg tabs without problem...

I have a DeWitts Spal fan with just on off relay, DPFI, and C4 blower fan which are the only significant power users at idle.....

:zzz:
Click to expand...



What about the regulator? I looked up that alternator and one place listed a HD external regulator included. So it is externally regulated, will it work with my current regulator?
Click to expand...



That place is rong......they are internally regulated, and since my local AZ no longer has one on the shelf, I suspect are getting harder to find.....the most common ones are 10 and 12 SI, but the 17 SI is king of the heap there.....

Look up the alt for a '79 Caddy seville, with RW defogger....i'ts what MY 17SI came off of......they are internally regulated and look just like your original but slightly larger diameter, they mount the same....

OR if you can handle the wiring issues, go for the CS14x , think I don't care for on the CS14x is the size of the unit, no room in there for the cooling needed for the greatly increased output....so it's early version the CS130 had all sorts of failures, I had 3 of them in 3 years with my '87 vette and it's one reason I sold the car for my '72 here tired of fixing it....

and the '72 is more comfy with the mods I have done to it....keeps my hotrodding interests alive....

:smash::smash::thumbs:
 
Last edited:
If it's hard to find a 17si you might as well just buy the Summit 100amp alternator: SUM-811001 black, $80 with warranty...., chrome $100
 
Twin_Turbo said:
chrome don't bring you home.
Click to expand...

Which is my philosophy too, I don't have the patience for it, I try keeping it 1/2 way neat, but to be going nutz over that stuff is not my bag, and the car shows it....too bad, so sad.....maybe I need clean up my act, but then it wouldn't be on the ROAD.....

:lol::lol::stirpot:
 
http://www.rockauto.com/catalog/x,carcode,1027482,parttype,2412

Ok Gene which one? If it does not include a pulley will mine fit? Sorry for the :noob: questions, but I do not know jack shit about this stuff. You would think with a year of engineering physics in college I would be better, but too much theory and no application. I read a thread about putting in an internally regulated alt in a 68 on CF but with some of the people giving the advice I am not sure I trust the information.

So If I install an internally regulated alternator where an externally regulated alternator once was what needs to be done?

This is why I was asking if it is even necessary given the lack of electrical items on my car.

I appreciate the help everyone!
 
68L71 said:
http://www.rockauto.com/catalog/x,carcode,1027482,parttype,2412

Ok Gene which one? If it does not include a pulley will mine fit? Sorry for the :noob: questions, but I do not know jack shit about this stuff. You would think with a year of engineering physics in college I would be better, but too much theory and no application. I read a thread about putting in an internally regulated alt in a 68 on CF but with some of the people giving the advice I am not sure I trust the information.

So If I install an internally regulated alternator where an externally regulated alternator once was what needs to be done?

This is why I was asking if it is even necessary given the lack of electrical items on my car.

I appreciate the help everyone!
Click to expand...


Going from External to Internal, all is needed is a simple wire adapter. If you can't find it, we sell them here at C.I. We carry the American Auto Wire adapter.
 
Last edited:
68L71 said:
http://www.rockauto.com/catalog/x,carcode,1027482,parttype,2412

Ok Gene which one? If it does not include a pulley will mine fit? Sorry for the :noob: questions, but I do not know jack shit about this stuff. You would think with a year of engineering physics in college I would be better, but too much theory and no application. I read a thread about putting in an internally regulated alt in a 68 on CF but with some of the people giving the advice I am not sure I trust the information.

So If I install an internally regulated alternator where an externally regulated alternator once was what needs to be done?

This is why I was asking if it is even necessary given the lack of electrical items on my car.

I appreciate the help everyone!
Click to expand...

Out of the bunch you got listed there #3 from top #20136 seems the best...I never heard of a 21 and 27 SI alternator....wonder if they playing games with the reman of them...I serious dunno....I got mine from Auto Zone but most houses can get locally, save shipping anyway...green grass item....AZ did have to exchange it 2x under lifetime warranty, nothing to do with the applications, just them being cheeep.....

Glen is with CI and they have your plug apparently....I did my own conversion on another car years ago....which is when I really got the time to go into these GM cars of the 60-70's and learn WTF they were doing....
combined with wiring diagram like for my '72 I found they have two wiring errors in their documentation.....I have them marked in my manual, not that I use it anymore.....backin 01-02 I completely rewired my entire '72 shark, on account of I got tired of messing with the stock harness, as long as it was down for other mods, like the rack and floorboards, and other forgotten aspects, I did the wiring too, out of sheer disgust....

only thing stock about my car is....well....NOTHING actually....edit....thats not right either...the windshield and side glass.....that's untouched....

:stirpot::devil::harhar:
 
Last edited:
So I got a 17si Delco alternator and the wire conversion 120.00 total. The alternator is a pig. I got it installed and it is not close at all to clearing my hood. Hope I can return it….
 
68L71 said:
So I got a 17si Delco alternator and the wire conversion 120.00 total. The alternator is a pig. I got it installed and it is not close at all to clearing my hood. Hope I can return it….
Click to expand...

OH NO!!, what is hitting?? the top of the adjustment tab??

how much differance in diameter is it?? should be only about a inch or so, maybe 1.5 inches....fits in my car fine....and to boot I have serp drive, and my '72 came with a 10-12SI originally, plenty of room for a 17SI still there....

I feel sick now...

you have a picture of your install, I maybe have the old brackets to my car yet....I would have to look....

you can have the brackets far as I"m concerned....

been some 15 years now, though, so I have to look at what in hell they even look like, but got a cabinet full of that old stuff....

I"m calling a vette source here in town over this....lemme get back to you meanwhile get a pix if your can please.....

:shocking::gurney::hunter::ill:
 
mrvette said:
OH NO!!, what is hitting?? the top of the adjustment tab??

how much differance in diameter is it?? should be only about a inch or so, maybe 1.5 inches....fits in my car fine....and to boot I have serp drive, and my '72 came with a 10-12SI originally, plenty of room for a 17SI still there....

I feel sick now...

you have a picture of your install, I maybe have the old brackets to my car yet....I would have to look....

you can have the brackets far as I"m concerned....

been some 15 years now, though, so I have to look at what in hell they even look like, but got a cabinet full of that old stuff....

I"m calling a vette source here in town over this....lemme get back to you meanwhile get a pix if your can please.....

:shocking::gurney::hunter::ill:
Click to expand...

Don’t sweat it gene. I already pulled it out so I do not damage my hood. The lower bracket is the factory big block bracket…it mounts to the block. It hits right on the upper mounting tab…I put a piece of gum balled up on top of the tab and it flattens out completely ¼” before the hood (factory bb) closes. The distance top tab to bottom is 8.75” and my original is just under 7.5”….it weights twice as much. The clearance to the valve cover is small. Maybe a longer upper mount and bigger belt would drop it down enough.
 
You must log in or register to reply here.

Latest posts

Back
Top