Durango_Boy

I wrote a paper years ago on swapping out your old inefficient SI alternator for a newer style CS style alternator. The newer style came in two types, the CS130 and the CS144. Both had varying outputs and case styles. While the CS130 is an easier swap, the CS144 is a higher power and larger unit, that while it's less prone to overheating, it's a tad harder to install.

The CS130 gives you a solid and clean 60 amps at idle, and around 100 amps at higher RPMs.
The CS144 gives you around 100 amps at idle, and depending on the model, 140 - 200 at higher RPMs.

I have picked up a bit more information on the swap since writing the paper originally so I updated the paper and re-hosted the new version so the new information would be available.

If you don't have the paper yet, or if you want to replace the original paper with the new one, here is the link so you can download and save it for future reference.

You can always contact me if you have any questions or if you need help finding something.

http://photos.imageevent.com/durango...%20Install.pdf

Enjoy.

7T1vette

DB:
Your new paper looks fine, but I didn't spot any info on increasing the size of power wiring for the main feed line and/or newly added components (the reason for upgrading in the first place). Wouldn't you want to increase the size of main feed wiring and the fuselinks in it?

Durango_Boy

Yeah I put in on page 5 that with the increased output it's recommended to add a jumper wire from the BAT terminal of the alternator to the lug on the starter that has the direct connection to the battery.

nate99

I'm getting close to picking up my late model alternator soon, but will admit that amp numbers mean next to nothing to me. If I am not going to be running any additional electrics (stereo, etc.) would the 130 be sufficient?

Durango_Boy

Yep. The CS130 will give you 60 amps at idle. That four times what your stock alt provides. Not to mention it's cleaner power and it will give you the option of someday adding accessories that might draw more than your stock setup.

nate99

Good deal, that should save a few clams vs. the 144 anyway. I bought the CS pigtail adapter from Lectric Limited when I bought a new engine harness. I'll read through your paper before I get that far. Thanks again.

TPI BOY

Does the cs144 use the same wiring adapter

Durango_Boy

Yes.

Bill Curlee

Damn nice article. Just in the nick of time. My OEM alternator has a bad diode in it which allows it to drain the battery when the car is off. I was just getting ready to replace it.
This will be a very nice winter up-grade project!

Bill

MN-Brent

CS130s have a higher reported failure rate than CS144. The research is all over the web.

Its worth the minimum effort to go CS144, IMHO.

B...

Durango_Boy

I've done a lot of research on this problem...mainly it's attributed to heat. The main cause is actually cheap Chinese parts used by Delco when they were making the original run of these alternators, and those cheap parts couldn't take the heat. I have battled it with a few tricks to try and get more air through the alternator with fair success. I have also learned that the remanufactured CS130s and new CS130s are being made with better quality parts...some still Chinese...but better quality and less susceptible to the heat built up by the smaller cased CS130s.

682XLR8

I see you addressed the issue of no gen light, similar to the problem I had on my 68 a few months back, which BTW is still holding up fine thanks to yours and others help from here on the Forum

Durango_Boy

Yep, the resistor problem was hard to nail down. The systems that didn't have a GEN light still had enough resistance built into the system to work with an SI alternator but the CS alternators simply required more resistance...at least 35 OHMs compared to around 12 OHMs.

Once I track down exactly what resistor is best I can make my own adapter plugs and outline how you guys can make your own a lot cheaper than buying the pre-made Napa plug.

MN-Brent

I thought about this resistor. Im not sure of the DC resistance of the field winding of the CS130/CS144. I have an extra CS144 that I should measure it.

There needs to be a minimum wattage rating for this resistor.

A quick google search showed 12V alternators may have 3-6 ohms resistance in the field windings. For worst case, we should use 3 ohms, which is close to nothing.

14.5Volts max alternator output assumption for worst case again

I= E/R
14.5 div (35+3) 38ohms = 381ma


P=E*I
14.5 * .381A = 5.53Watts

A 35ohm 5.5W resistor would be minimum to handle the power dissipation and not burn up under your dash.

This guide recommends 300-500ohms.
http://www.partsamerica.com/product_...ap/WRW/523.pdf

I think this may get you by in a limp mode as the current through the field windings may not be as high, and therefore not allow the alternator to develop as much voltage-power output.

At 300ohm, you have 47ma current with a 0.693 Watt dissipation.

So be sure you also give up a power dissipation recomendation in your paper so nobody finds there resistor getting red hot, etc...

Brent.

worship79

If I may ask a dumb question? Seen the prices of mentioned alt's versus the 100 amp ones on fleebay for about $70,-... why do I need one of these?

Durango_Boy

First, the CS is a much more efficient alternator. It's designed for computer controlled cars where the power levels need to be much more stable and 'clean'.

Next, the SI style alternators have a very low idle output compared to CS style alternators. Even a 100 am SI alt will only give you 30 - 40 amps at idle, and usually with the high amp versions that idle output actually goes down and you won't see that 100 amps until you're half way to red line.

Finally, SI alternators get much more prone to failure when built to put out 100 amps or more. The reason there are so many in cars these days without failure is because there isn't a true draw for that much power or the engine RPMs never get high enough for long periods of time to allow that kind of steady output.

The higher output options of the CS alternators are perfect for cars and trucks that have things like A/C, electric fans, auxiliary lights and fans, and stereo systems. If you don't have anything like this then a stock alt will usually fill your needs.

worship79

Remember me buying your clear glass headlights? Hence my question: after driving for a short while (say 5-10 minutes or so), even only woth the low-beam H4 lights on, voltage starts to drop rapidly when idling.

My conclusion was I need a new alt, but what alt exactly I'm trying to find out. From you paper I understand any '87 - '91 C4 alt will do? Those would perhaps be easier to lay my hands on over here.

Durango_Boy

Yeah, and don't forget that I can always buy one here and ship it to you. I might be able to find a good new one AND ship it for less than they cost there. Do some checking, and get back to me on the price of them there and we'll see if I can't score you one cheaper.

worship79

That would be great, thanks!

TPI BOY

Does the 85 vette have the right conector for the
cs144