What's old is new again. Alternator upgrade options

[zKars]

So you're on the road at night cruisin' in your Z. Slowly you notice that your headlights are getting dimmer and dimmer. You check your ammeter or voltmeter and see that your system is in discharge mode. Oh crap. Belt fall off? I hope so. Nope, still there and tight. oh oh oreo...

Well you got that "big" 60 AMP internally reg'ed ZX alternator just a few month's ago, but I guess it gave up the ghost. Trouble is you're in Podunk Kansas and the local AutoZone doesn't have one in stock and can't get one for four days. Now what?

Me, I'd rather have a common alternator, one I can get anywhere. And I mean anywhere.

About the only sane choice is the GM 10SI body alternator.

I know I know, you're thinking, "this GM alternator thing has been discussed to death", well, yes, but if you go looking you will find a variety of GM alternators discussed and the mounting of them is a bit of a mess.

Advantage 1: Available anywhere,
Advantage 2: Cheap
Advantage 3: Internally regulated, one wire.
Advantage 4: Available from 100-140 amp. Electric fans, big lights, big stereo, no problem.
Advantage 5: Available anywhere. Yeah, again.

Mounting is pretty easy after you get past the first issue, ie that the lower alternator mount has to be modified. It has to be cut and drilled.

Here is where to get one. I picked mine up from Mopac in Calgary for $134 CAD all taxes in

It fits the stock space well, even uses a 8x1.25 bolt at the upper mount point.

 

You need to cut the mount off to leave 1.75-1.8 inches remaining. The cut face must be flat and flush and square the mounting surface. The alternator position is determined by this face, it has to be decent. The drill out the 8x1.25 threaded hole to 3/8" through the whole thing.

You'll need a 4.5 x 3/8 grade 8 bolt, washers to space it just perfect to match the plane of the water pump pulley, and a nut/lock. 

 

I used a 4L350 drive belt.  35 inches long. 

PS, I have one of these in my Z and 510. Don't leave home without.

Here is where to get one if you're the on-line type:

https://www.performance-world.com/ProductDetails.asp?ProductCode=360520

I got mine at Mopac in Calgary for $135 CAD all taxes in. Show Chrome polish was $10 more. Yes really.





Cutting, facing and drilling those brackets properly is a bit tricky without a mill. I have a couple of spares if you want one. I can wip them up in 15 min. Or send me yours.

 

All I'm missing here i year/make\model spec to tell the young'en behind the counter when you need to find one in Podunk Kansas.  (I've been there, its not so bad...)

[wheee!]

Love it... added to my build list!

[Zed Head]

Not sure, exactly, what you mean by "one wire".  I don't think that the modern car versions come that way from the factory, you have to wire them that way.  The tractor versions and certain models come in one-wire form, apparently.  Also, the info available on the interweb shows numerous variations of the 10SI model, some at very low output.  And, of course, there are opinions on one vs. three-wire setups.

 

I agree though that universality is a good thing for parts.  I've been thinking about that for other parts also, like injectors.  Eventually, sites like this will be all about making other parts work on our cars.  If cars aren't all electric by then.

 

Here's some interesting reading I've collected, on the topic of alternator swaps.  There's a ton out there, but these are easy reading.  The mounting positions can be different also, I believe.  Anyway, one model number could probably be found in here somewhere that does the job.

 

http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html

 

http://www.madelectrical.com/electricaltech/onewire-threewire.shtml

 

http://www.tuffstuffperformance.com/index.cfm?ptype=results&category_id=270&mode=cat&start=49

 

http://www.ihpartsamerica.com/forums/electrical-tech/3364-delcotron-10si-alternator-thread.html

[Walter Moore]

He is talking about a "Single Wire" hot rod alternator, not an OEM alternator for any particular GM product. I tried that when I first got my car running, but could never get the belt aligned properly.

[Zed Head]

The info on GM 10SI alternators suggests that maybe he's talking about an off-the-shelf product.

 

I wonder if GM didn't just use metal with residual magnetism, lending all of their products to "one-wire" possibility.  The 10SI masses write about a special internal regulator that starts charging at low RPM, with a "one-wire" wiring.  I'm not really clear on who's selling what.

 

http://www.windbluepower.com/Delco_10SI_One_Wire_Alternator_p/7127-sen.htm

 

Lawnmower world - http://www.atlma.us/index.php?topic=43.0

 

Boatland - http://www.marineengine.com/boat-forum/showthread.php?388418-3-wire-vs-1-wire-alternator

 

And stories about home-made one-wire setups draining batteries because of the slight draw from connecting the battery to the excitation terminal. Which is actually a two-wire one-wire, in concept, I think.   http://www.ford-trucks.com/forums/115484-1-wire-alternator.html

 

There's a couple of guys on here who could go in to much detail on the one-wire phenomenon.

[Zed Head]

Sorry zKars, this is just a really interesting subject.  

 

Back to the 10SI.  I think that it can also be wired as 3 wire, with charge light and excitation intact, making it a normal internally regulated option.  The mounting of the unit is the key.

[cencalZ]

I followed the link rustfree'sh supplied and copied the description.

 

Description  

 

Going for an OEM look but want a high output alternator? This is for you! This 100A alternator can be connected in 3-wire OE style, or in 1-wire hook up for custom applications. GM 10SI style. Satin finish with yellow zinc fan and pulley. Converting from an external regulator? Click Here

 

Now it states a GM 10SI style

[Bonzi Lon]

There are enough of us near Podunk, Kansas that together we could get you back on the road, one way or another. 

 

Bonzi Lon

[zKars]

Thanks for all the feedback.

I agree that getting the mounting bracket right is the key to the whole situation.

Clearly I find the one wire (really two if you count the ground lug) very handy as it totally simplifies the wiring. True you loose the ability to have the charge light, but with an ammeter or voltmeter, which we all have, there should be no mystery if the thing is charging or not.

I meant it when I said I'd make up mounting brackets for who ever needs one. Got the alignment jig built to mill them flat and straight and to drill the 3/8 hole straight through.

I have nothing but good things to say about the good citizens of Kansas. The place looks exactly like home (Saskatchewan). No mountains or trees to block the view.

[zKars]

Quick note on the pulley alignment method.

Assuming you have a properly prepared bracket (see above), you just need a 18" or so long straight edge.

You can mount the alternator, then put the straight edge across the face of the alt. pulley, just above the center nut. You want the maximum amount of contact with the pulley edge/face.

Angle it toward the water pump pulley. Try to touch the straight edge to the pulley face so it touches enough of the circumference to let you feel a positive stable contact. Yes the water pump pulley has a large center pertrubance, but its large enough diameter that you can easily get good contact with it above the center bump.

Either the water pump pulley if ahead or behind the plane of the alt. pulley. Put the straight edge on the pulley that is the most forward, leaving a gap between the edge and the pulley that is most rear ward. Sight the gap across the pulley and straight edge and ensure the gap is consistent. If its not parallel, then the alternator is mounted skewed. Go to step 1.

If the mounting bracket was cut to 1.75, then the alternator should be behind the water pump pulley.

If it is parallel, then you see the gap you have to fill with washers, between the mounting bracket and the alternator bracket to space it forward, which is the normal case.

If the alternator is in front of the water pump, then you will have trim some off of the front face of the mounting bracket. This must be done carefully to ensure it stays flat and square.

[zKars]

Had to include a pic or two of the final result.

[Zed Head]

A ha.  That tensioner with the heim joints wasn't mentioned before, was it?  That's a key part.  I don't know that the stock one will work.  Looks good.  Is it harder to squeeze down between everything to install?  I remember lots of maneuvering and some flexing of parts to get my ZX alternator installed.  Any bigger and I don't know that I could have done it without removing parts.

 

Is that an inline electric water pump in your coolant return line?  Or just a large fitting for the flexible hose?