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I used a GM CS130D. It is the same size as stock, puts out 105 (or more) amps or more and has internal fans to provide additional cooling. It also provides much better output at idle and low RPMs than the modified stock S10 and S12 alternators. Alternately, GM uses the CS 144 for its heavy duty applications. It is larger and may take some alterations to fit. There are many previous threads on the CS140, do a search.
Last edited by Rotonda; Sep 9, 2014 at 06:28 AM.
Reason: Addition
I installed an electric fan and a 100 amp 10si, it had no juice at idle. Also it would just about die on hot days.
The CS130 never falls below 14 volts, idle, hot days or with lights, ac and fan on...
It mounts the same as 10si unit.
Yea the 10Si is the old style. The CS130 is the style that came next and what many use. It makes more power and more reliable as well.
Only problem with that is that old ones were often mounted on the exhaust manifold. They could stand a lot of heat. The new type is not designed for that, and are mounted away from manifold heat usually on serpentine systems. Under a lot of continuous use and mounted on the manifold, the internal plastic parts will melt and fail.
Only problem with that is that old ones were often mounted on the exhaust manifold. They could stand a lot of heat. The new type is not designed for that, and are mounted away from manifold heat usually on serpentine systems. Under a lot of continuous use and mounted on the manifold, the internal plastic parts will melt and fail.
Well, on a sb like in a 79 it's mounted on the face of the cylinderhead. However I did notice that the headers heat up the alternator considerably. Maybe that's the reason why I'm seeing the battery loose power... ?
Does the CS130 have a serpentine pulley ? Definately need to retain the V-belt system.
Last edited by Belgian1979vette; Sep 9, 2014 at 10:55 AM.
I picked up all the accessories and brackets from an '89 Firebird 305 engine and converted to a serpentine system with the Firebird CS130 alternator.
That's what I am going to do as well. Just need to rebuild the engine first as my heads do not have the bolt holes.
You can convert the CS130 to run on a V belt. Just change the pulley.
I also don't see how a CS130 would perform worse than a 10si due to heat? I have not broken down each part down to its core just rebuilt plenty of GM alts in my tech days.
EDIT:
Seems some CS130s have heat fins on the back while most do not. That could be part of the heat issue with the CS130's some have. That and some cheap aftermarket rebuild kits seem to be a problem as well.
I also don't see how a CS130 would perform worse than a 10si due to heat? I have not broken down each part down to its core just rebuilt plenty of GM alts in my tech days.
EDIT:
Seems some CS130s have heat fins on the back while most do not. That could be part of the heat issue with the CS130's some have. That and some cheap aftermarket rebuild kits seem to be a problem as well.
I used one off of an `89 on my 66. It was mounted on a bracket that was on the manifold bolts, as most were in the C2- C3 era. It operated pretty well until I made a long trip with it. It had a sudden failure at about 400 miles. Upon examination, it was obvious that things got a bit hot. Plastic parts and holders melted and self destruction. The earlier type has better ventilation and no plastic mounting. I understand that they had problems with the diode bridge getting hot anyway, so that may have contributed. There is a kit to convert the housing for cooling fins. That may help with the problem. I use the old style now and have had no problems with it for 70K miles.
There are manufacturers that make higher current 10si alternators (which will look just like the stock alternator) but they still suffer from the basic design limitations of the 10si alternator design. The basic alternator design causes a low charging current at low rpm.
One of the main reasons for the CS130 design was to produce more current at low rpm when the engine is idling (to power fans and AC and other large loads). The CS130 can produce more current at engine idle than your stock alternator is rated for. About 70A at idle and then it goes up to 105A at rated current with more rpm.
You need to run a heavier charging wire. I recommend 6 gauge between the alternator and the solenoid. With your under-hood accessories I would put a junction and terminal block in the wire in a convenient location. The alternator has a S terminal in the 4-pin plug. This is the remote voltage sensing. Wire it to the terminal block as well.
Jegs sells a complete kit [brgs, diode, rectifier, brushes with holder, stud] to upgrade you're original Delcotron to a 100 amp output alt for $40. MSD sells alts, direct bolt in replacements. In both upgrades increasing the wire off the alt to a larger AWG [number 6 or 8 depending on length] is a deffinate must. The 69 is getting is getting the Delcotron, wanna keep the original look. The 6t8 has the MSD, needed a stouter alt, for the higher RPM usage it sees. T
Only problem with that is that old ones were often mounted on the exhaust manifold. They could stand a lot of heat. The new type is not designed for that, and are mounted away from manifold heat usually on serpentine systems. Under a lot of continuous use and mounted on the manifold, the internal plastic parts will melt and fail.
Externally, the CS130D appears to be a completely different design. It looks similar to a Mopar alternator, with a rounded, ventilated case and no external fans. It is a redesigned CS130 with dual internal fans and far better cooling than the original, to be more reliable under higher heat conditions.
This is the reason I chose the CS130D model for my conversion.
Last edited by Rotonda; Sep 10, 2014 at 07:18 AM.
Reason: Addition
Good comments from some above. The OEM alternators 10/12SI are not the best units for more amperage due to the design limitations of the housing and the cooling efficiency. They also will generally not charge as well as a stock unit at idle but will provide more amperage at higher RPM's. I had a 120 amp stock unit for my 78 and it would not charge well at idle under load-the generator light would flicker on and off faintly. I finally upgraded to the CS-144 a few years back since it fits perfectly using the stock brackets-it is a bigger housing though and looks bigger BUT fits perfectly, has a stock output of 140 amps, is considered a much better unit than the CS130's, and charges like a champ at idle which is what I needed for my hella Euro halogens-55/60 lows and 100 watt high beams.The only alteration needed was the adapter wire seen in the picture to connect the stock wiring plug to a CS-144 which is easy to get.
Good comments from some above. The OEM alternators 10/12SI are not the best units for more amperage due to the design limitations of the housing and the cooling efficiency. They also will generally not charge as well as a stock unit at idle but will provide more amperage at higher RPM's. I had a 120 amp stock unit for my 78 and it would not charge well at idle under load-the generator light would flicker on and off faintly. I finally upgraded to the CS-144 a few years back since it fits perfectly using the stock brackets-it is a bigger housing though and looks bigger BUT fits perfectly, has a stock output of 140 amps, is considered a much better unit than the CS130's, and charges like a champ at idle which is what I needed for my hella Euro halogens-55/60 lows and 100 watt high beams.The only alteration needed was the adapter wire seen in the picture to connect the stock wiring plug to a CS-144 which is easy to get.
I read somewhere that the housing needed to be turned to get the terminals in the right location.
You also run headers. Any probs with heat or are they jethot coated ?
I read somewhere that the housing needed to be turned to get the terminals in the right location.
You also run headers. Any probs with heat or are they jethot coated ?
That is correct the alternator has to be clocked for our cars and the place I bought my CS-144 did that before it was shipped.My shorty headers are ceramic coated-no issues. When I bought it a few years back, I recall it was $169/179 new-great alternator.Clocking your alternator yourself is not hard-just loosen and remove the casing bolts, slightly separate the 2 sides and turn to the desired position-not a big deal if you have to do it yourself.
Last edited by jb78L-82; Sep 10, 2014 at 05:38 PM.
Clocking your alternator yourself is not hard-just loosen and remove the casing bolts, slightly separate the 2 sides and turn to the desired position-not a big deal if you have to do it yourself.
Just make sure you turn the front casing. Keep the back casing and the middle stator core together since there are wires going between them.
stronger alternator
