How far apart are the bottom mounting feet on an S30's alternator?

[twsutt]

I'm looking to upgrade my alternator and I don't have access to my Z at the moment. Is it the same distance as the "J Mount" alternators? Are the feet 80mm (3.15") or 100mm (3.95") apart?

Thanks in advance,

[Zed Head]

What is a "J mount" alternator and what "upgrade" qualities are you looking for?

The typical change for your 1975 car might be to an internally regulated alternator but all it really gets you is one less component, the external regulator, and the benefits of solid state regulation over the mechanical points of the external regulator.

[twsutt]

"J mount" alternators are 2 footed alternators produced for many late model GMs and Chevrolets - I believe the feet are exactly 4" apart (someone please correct me if I'm wrong.)

I've replaced the mechanical radiator fan with electric cooling fans and I usually drive with my headlights on for visibility (yes, both of these items are using relays so the current isn't having to flow through the stock harness.) Now that I no longer have overheating problems or dim headlights I am now experiencing battery drain problems due to the low output of the alternator at idle.

When I drive my car to work it usually takes me about an hour to travel 22 miles to get home - most of that time is spent sitting. Last Friday, due to construction, it took me almost 1:45 to get home and once the engine was shut down (at my son's daycare) I was unable to restart the car due to a drained battery. Fortunately, my wife was home - less than a mile away.

I don't need a high output 300 amp alternator, but I would like something that will put out at least around 50 amps at idle (100 - 140 amp max.) I also plan on converting to a internally regulated alternator.

Mechanically all alternators are the same; rotor, stator, diode set, regulator. The housing is my current concern - what will fit.

[Zed Head]

Here are a couple of links I saved from when I was looking at an upgrade.

http://forums.hybridz.org/index.php?showtopic=49864

http://forums.hybridz.org/index.php/topic/67531-ac-delcogm-alternator-swap-part-2-cs144-installation/page__p__634683__hl__alternator__fromsearch__1#entry634683

Search cgsheen or bjhines on the Hybridz site also, you might find some info. I think that one of them is using the CS130D alternator,which is supposedly the state-of-the art and a little smaller than the CS144.

[twsutt]

Actually, the CS130D with two bottom mounting feet is what I've been looking at.

I'll check out cgsheen & bjhines over on Hybridz.com and see how well the feet match up or need a shim or conversion bracket. I've read quite a bit about mounting the 10SI/12SI (thanks HizAndHerz) as well as the CS144 (thanks ktm) over on Hybridz. Thanks for the info.

[rustyZ]

80mm on a 71

[twsutt]

rustyZ - A man of few words. Strait to the point. I like that.

Thanks.