AC Delco/GM Alternator Swap Part 2 - CS144 Installation

[ktm]

Please read the following link first if you have not done this swap:

 

http://forums.hybridz.org/showthread.php?t=115550

 

It is the detailed write-up by Hizandherz on how to install an AC Delco/GM alternator si series (10si and 12si). The modification is very straight forward and only requires modifying the lower alternator mount.

 

In the thread, Nigel brought up the CS144 alternator which has the ability to put out 95 amps at 2000 rpm (alternator RPM) while the 12si only puts our 50 amps. I've been having idle voltage issues with my 12si and it is very evident when the fan kicks on. The idle drops, gets a bit rough, surges, etc., until the fan turns off. Load it up at idle with a fan, lights, and aftermarket stereo and you get the idea.

 

So I decided to jump right on in and try to get the CS144 to work. Following is a write-up that follows Hizandherz if you want a CS144 instead of a 12si. The CS144 is available on 1992 to 1996 Cadillac Devilles (any Caddy with the Northstar), so if you go to Autozone, ask for one from a 1994 (to play it safe) Deville.

 

Below are pictures of the 12si and CS144 side by side. Dimensionally they are not much different, but the CS144 is a bit deeper and slightly larger in diameter than the 12si.

 

 

 

 

 

 

The bottom mounting tab is dimensionally the same between the alternators, but the top mounting tab on the CS144 is slightly thicker than that of the 12si. Additionally, the upper mounting tab of the CS144 is threaded for M10x1.5. This will require modifying the stock alternator bracket to allow for an M10 bolt.

 

All you have to do here is trim the upper mounting tab to the same dimension of the 12si tab.

 

12si tab - 5/8-in. thick

 

CS144 tab - 3/4-in. thick. The black mark is my cutting mark.

 

Finished cutting.

 

Next, you will need to switch out the serpentine pulley for the L28 v-groove pulley.

 

Finally, you will have to modify the stock alternator bracket. The slot needs to be widened as mentioned above to fit an M10 bolt, but it also need to be lengthened a bit to allow for a slightly longer belt. You can not use the stock belt as it will be too short and the alternator housing will not clear. I used a Duralast 17360 belt with dimensions of 1.3 cm by 91.5 cm.

 

Now for the electrical modifications. Never fear, these are easy. To make it stupid simple, go to Napa and get part number EC82. It is an electrical connector that is made to convert si alternator harnesses to CS alternators. It has two connectors, one on either end as shown below. The yellow wire is the exciter and the red is the battery sense. The yellow wire has a resistor attached because the Devilles had a charge light that had resistance to drop the voltage. Simply attach your wires to the new subharness and you are done!

 

 

I have noticed that I now charge around 13.1 to 13.3 volts at idle, a significant jump for me. I have yet to fully test it, but this should help out considerably.

[jeffp]

Seems now you are running down the alternator hole like I did. I tried three versions of alternators in my car and the AD244 unit has been the best part so far.

I did the 100 Amp upgrade to the stock unit. Not enough current at Idle. I then went to a moded GM alternator to 150 Amps, and it also was not good enough at idle.

The AD 244 was the best, but it also doesn't seem to provide the advertised 95 Amps at idle, but it is close enough for me. When the battery is fully charged, I can run the lights, the stereo and all the other electrical stuff, water pump, electric fan, fuel pump.

So though the unit doesn't provide the ideal current for me at idle, it does work when the battery is charged.

I was shooting for an alternator the would still charge if needed at idle with all my electric stuff going, almost got there. I have it posted on my web page if you want to take a look.

[Careless]

Seems now you are running down the alternator hole like I did. I tried three versions of alternators in my car and the AD244 unit has been the best part so far.

I did the 100 Amp upgrade to the stock unit. Not enough current at Idle. I then went to a moded GM alternator to 150 Amps, and it also was not good enough at idle.

The AD 244 was the best, but it also doesn't seem to provide the advertised 95 Amps at idle, but it is close enough for me. When the battery is fully charged, I can run the lights, the stereo and all the other electrical stuff, water pump, electric fan, fuel pump.

So though the unit doesn't provide the ideal current for me at idle, it does work when the battery is charged.

I was shooting for an alternator the would still charge if needed at idle with all my electric stuff going, almost got there. I have it posted on my web page if you want to take a look.

 

AD244 hmmmmm.

 

I have a GM12 si that is a remanufactured casing (the new ones are made cheaply and not as well built apparently).

 

Also, if i may make a slight suggestion... your web page button links are what we in the business call "mystery meat" ... do you want us to click through all the links to find what we're looking for? always put words with small images

[Careless]

LOL @ "So that's my story and I'm stickin to it LOL."

[darom]

Have you upgraded your fusible links/Maxi-fuses to allow for more AMPs? If the default alt. circuit is asking for 50-60amps, what kind of maxi-fuse would you use with either AD-244 or CS-144 alternators?

 

Thanks!

[TrumpetRhapsody]

Great writeup! Now I can sick my GM dealership friend on some caddy's to find me a nice cheap alt.

[Nigel]

Hey, cool! Thanks for doing the legwork on this KTM!

 

Nigel

'73 240ZT

[rejracer]

My Z specialties Alternator just failed, and now I am looking at options. This is a great writeup, so thanks to all who have done their homework.

 

Jeffp's post made me investigate the AD244, and I could not find a good answer as to the Pro's or Con's of the AD244 versus the CS144.

 

I called up Alternatorpart.com and spoke with Randy. I asked him what alternator would provide the best amperage at idle and he said it's a wash between the CS144 and the AD244 in stock form. The two alternators use the same regulator, rectifier (see note) and stator. The difference between the two is the AD244 has a different rotor that is the same electrically, but has a different shape to it for the new case design. From the factory they have different recitifiers, which is a change in manufacturing technique, but the components (diodes) themselves are the same. The rebuilt units they sell use the same upgraded rectifier.

 

What he said makes the biggest difference is the 200 amp stator. They use the same stator when upgrading a CS144 and AD244. Although I certainly don't need 200 amps of power I am going to go for one of their 200 amp units to get the idle speed amperage increase to the best that it can be.

 

He also indicated the difference between the 140, 170 and 200 amp versions are the following:

140 amp - factory configuration.

170 amp - upgraded rectifier bridge.

180 amp - upgraded rectifier and stator.

 

In other words the 170 amp version is going to be the most reliable as it's only upgrade improves reliability, and the 200 amp is going to provide the best idle voltage/amperage.

 

I am going down this path because it gives the best of both worlds. It's an upgraded unit, so the electrical performance is there, plus if it fails I can still go down to autozone and pick up something that will work until I can get the uber alternator fixed again. It also does not hurt that this is the same alternator used in my impala. One advantage is the CS144 has more case mounting styles, and is therefore a bit more flexible. I like the look of the AD244 case, and it probably cools better. The CS144 case protects the internals a bit better imo, and since I will nowhere use the capacity of this alternator the increased cooling (if any) of the AD244 is moot. Overall the CS144 seems to be a bit more rugged. If anyone has more experience with these, please chime in.

 

For others that are on the fence concerning this upgrade... I learned to rebuild these things in college, so I am comfortable taking them apart. I may need to modify the case a bit, and if it were to fail, I would go to autozone and buy an alternator. I would then take the old unit and test it and just buy the needed parts from alternatorparts.com and rebuild, and swap it out. If you considering the swap and don't want to deal with that complexity the autozone solution may be the best route to go the first time. However if you do go the autozone route, I would be concerned about modifying the case, you cannot (well should not) return an alternator that has the case modified as a core because this is usless to the rebuilder.

 

I will look at a custom mount for the new alt, I don't like the existing solutions requiring modifying a factory mount, it looks somewhat flimsy and does not appear to support the alternator as well as I would like.

 

KTM, do you have installed pics? This might put my mounting concerns to rest. Good writeup btw..

[ktm]

I will look at a custom mount for the new alt, I don't like the existing solutions requiring modifying a factory mount, it looks somewhat flimsy and does not appear to support the alternator as well as I would like.

 

KTM, do you have installed pics? This might put my mounting concerns to rest. Good writeup btw..

 

http://forums.hybridz.org/showthread.php?t=137235

 

The alternator is mounted using a Class 10.9 (SAE Grade 8 - can't get much better than that) 10 mm bolt. Flimsy is not the word I would use.

 

Edit: I should also clarify that if you go with the turnbuckle as shown in the picture, you do NOT need to modify the upper part of the alternator, since the turnbuckle eyelet attaches to the outside of the alternator tab.

[rejracer]

I see what you are saying, and would agree it looks very rigid.

 

What I am trying to say is that with the single connection point to the lower mount it is far more likely to break the bolt than if it were supported at 2 points. Granted Class 10.9 is the way to go, but time will take it's toll. I would be worried that the constant flexing of the bolt from the acceleration/deceleration of the engine, vibration and jolts from rough roads will lead to breakage, even on a class 10.9 bolt. Question is how long will it last i like how easy the mod is though.

 

I don't know what I will end up with as far as mounting is concerned, but I will probably try and fabricate a mount using plate steel. I think this is the best approach for long term reliability. If it works out I might model it up and have a machine shop make me one of nicer construction that I would be able to do in my garage.

 

Thanks for the info.

[ktm]

The original mount relies on a a single bolt for the structural support. The upper bolt is not used for structural support only lateral adjustment of the alternator. If you opt to use the turnbuckle, that will provide the additional structural support you are seeking.

 

Don't take this the wrong way, but I think that you are overly concerned about the mounting on the alternator.

[rejracer]

it's been a while, i've not driven the datsun for almost a year now because of a dead alternator. Well I just ordered the alternator from alternatorparts.com. Here is what I ordered:

 

I ordered the 200amp alternator D1-CS144-A200 http://www.alternatorparts.com/CS-144_Special_offer.htm

both serpentine and v-groove pulleys

Datsun mounting bracket. http://store.alternatorparts.com/partnoa285.aspx

OEM pigtail.

 

I did not order the the self exciting regulator as it does not have the provisions for a charge warning light. I have a 280z volt gauge that I will be installing. I plan on removing the factory ammeter from the setup. I have also purchased the equipment to make my own battery cables, so I will be making a custom set. I plan on running 2ga cable between the battery and the alternator, and 1/0 between the battery and starter. I know it's overkill, but I will have stable voltage from idle to redline

 

I can't wait to start driving it again. I drove it around the block this week, and it was running great. I had recently put in a lightweight flywheel, and a 81-83 NA trans, and I want to drive it again!

[captken]

it's been a while, i've not driven the datsun for almost a year now because of a dead alternator. Well I just ordered the alternator from alternatorparts.com. Here is what I ordered:

 

I ordered the 200amp alternator D1-CS144-A200 http://www.alternatorparts.com/CS-144_Special_offer.htm

both serpentine and v-groove pulleys

Datsun mounting bracket. http://store.alternatorparts.com/partnoa285.aspx

OEM pigtail.

 

I did not order the the self exciting regulator as it does not have the provisions for a charge warning light. I have a 280z volt gauge that I will be installing. I plan on removing the factory ammeter from the setup. I have also purchased the equipment to make my own battery cables, so I will be making a custom set. I plan on running 2ga cable between the battery and the alternator, and 1/0 between the battery and starter. I know it's overkill, but I will have stable voltage from idle to redline

 

I can't wait to start driving it again. I drove it around the block this week, and it was running great. I had recently put in a lightweight flywheel, and a 81-83 NA trans, and I want to drive it again!

 

 

just wondered, how did this setup work out for you? I have a 83zxt and have problems with misfire on boost. I think the problem may be spark related.

My alternater is near dead and want to replace it. This upgrade, might solve my problem.

kenny.

[Nigel]

just wondered, how did this setup work out for you? I have a 83zxt and have problems with misfire on boost. I think the problem may be spark related.

My alternater is near dead and want to replace it. This upgrade, might solve my problem.

kenny.

 

Unless you're planning on doing some welding, or you have a monster car stereo, a regular 140 amp CS144 will be more than enough. The IDLE output alone of the CS144 is 20+ amps more than the MAXIMUM output of the OEM 280ZX alternator!

 

Nigel

'73 240ZT

[rejracer]

Kenny,

Alternatorparts.com sent me the wrong front housing on the alternator, I was able to mount it but the upper mount geometry is not good and it allows too much flex, so the belt slips on sudden acceleration. I called them up and they are sending me the right front housing with bearing. This is perfect as I get to keep the other housing. I needed to clock the alternator anyway, so I would be removing it and partially disassembling it to do so.

 

 

I am currently running a stock balancer and the GM alt pulley which is larger and thus turns the alternator slower. Idle output at 850 rpms is around 12.5v, not what I am shooting for. I get a full 14.45v at 1150 rpm's. I will swap out the alternator pulley for the smaller nissan pulley. I also have a BHJ Damper which I believe has a slightly larger diameter than the pully I am currently running. I will have to do some math to figure out the current alternator shaft speed at 1150 rpm to know where I will be at when I change out the pulleys. The goal is a solid 14.2 to 14.5v at 700 RPM.

 

As far as the max output Nigel is right, you don't need the 200 amps, I upgraded it because the better stator has a slight increase in idle output, and I do mean slight. The main reason I upgraded is the higher quality bridge rectifier, which is a reliability thing, not an output increase. If you wanted to save a few bucks get a junkyard 140amp model, and if you wanted to have more of a workhorse alt, upgrade just the bridge rectifier. Upgrading the bridge rectifier will also increase the load rating to 170amps.

 

One thing to note though, is that GM runs much larger crank pulleys, so the stated Idle output does not apply. You must look at the application that GM is using the alternator on, and calculate the shaft RPM speed (you could also just look it up on the Delco-Remy service manual). From there do the math to calculate what your shaft speed will be, and then look up the shaft speed on the Delco Remy service manual to determine what your output will be.

 

I don't know if your misfire issue is voltage related or not, so I can't speak to that. I can say out of the box, this alternator might not be what you are looking for.

[Nigel]

I posted the CS144 output in the thread that KTM refers to in the beginning of this one. Here it is again:

 

http://forums.hybridz.org/showthread.php?t=115550

 

To summarize, the CS144 puts out 95 amps at 2000 alternator RPM. The stock Z alternator and crank pulley ratio works out to close to 2:1, so if you use those parts on the CS144, you can get close to the 2000 alternator RPM at 1000 RPM engine idle. I installed the CS144 in my Z at the beginning of this year, and this was the first time since adding the EFI system, 17 Amp rad fan and other electrical options that I never once noticed the alternator struggling to keep up.

 

Here's some pictures of my install:

 

Mechanical assembly order:

 

Electrical components:

 

Below is the fully assembled alternator waiting for installation. Note the upper adjustable arm. This is a an extruded aluminum turnbuckle that I got from Home Depot for around $3! The eye's have 5/16" thread, and I picked up a reverse thread jam nut at a local fastener supply store so that I could have jam nuts on both ends (probably overkill). I had a buddy make up a 1/4" spacer to correct for the offset where the arm bolts to the timing cover and to make up the difference in diameter between the eye (1/2") and the bolt (8mm). You could just use some washers to correct for the offset.

 

Below is my modified lower bracket as per HizandHerz writeup. Rather than drill it out for a 10mm clearance hole, I drilled and tapped it with a 10mm thread. But I found that it was difficult to hold the alternator and get the bolt started without cross-threading it. So I ended up just drilling it out and using an extra long bolt and a nut.

 

Here's the final install (ignore the wire and terminal colours. They don't relate to 0 and 12V):

 

Nigel

'73 240ZT

[ktm]

Note the upper adjustable arm. This is a an extruded aluminum turnbuckle that I got from Home Depot for around $3!

I posted about that modification too! As I wrote in this thread, by going to the turn buckle design you elminate the need to trim the alternator tabs since you are mounting the adjustment arm in the front.

[Nigel]

I posted about that modification too! As I wrote in this thread, by going to the turn buckle design you elminate the need to trim the alternator tabs since you are mounting the adjustment arm in the front.

 

Oh yeah! I forgot about that. Your post is what sent me off to Home Depot in the first place. Great idea. I really like the extruded aluminum version I found at the Home Depot near me. It looks way more expensive than it really is. Maybe I'll get it anodized some day. I'm not sure if all the Home Depot's carry the same ones. How do you like the spacer I had made up? It takes care of that misalignment issue. You need a longer bolt though. I think I used a 90mm M8?

 

Nigel

'73 240ZT

[ktm]

The spacer idea is a good one. I wound up "shimming" it with washers and had to use a longer bolt as well. I really like that extruded turnbuckle. I did not see it at the Home Depot near me. I'll have to check again.

[Hardwyre]

Ktm, sent you a PM. All in all it was asking if you MUST use a Northstar-version alternator of the CS144. The CS144 for non-NS Devilles is about $30 less on average for the same rating. I like the turn buckle you're using; I'll have to see if I can locate one. Probably end up powder coating it along with the bracket.