Alternator reccomendations

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needsaresto

needsaresto

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Tell me your usage,the good ,bad and the ugly. Please give a more comlete description of your electrical system as well,including any upgrades,or if it's stock. I am seeking infomation that will help in selecting the correct alternator for my application. Will be a big block,stock wiring system (upgraded to heavier wire) ,but with headlight relays,and an amp gauge bypass. Probably a heavy demand for electricity with my car.Most likey a multispark ignition,home brew fuel injection, and hopefully a Classic air con system.

So I'm going to need a fair amount of amps...Might even upgrade to some sort of power door popper.
 
Despite what I see in your avatar, I would suggest a Delco alternator, like a 12SI, CS-130, or CS-130D.

I mounted a 78 amp 12SI on my small block and so far it's been able to keep up even with my high amp Contour fan at idle. I have totally rewired the car, but it's very similar to that of the amp gauge bypass. I'm not sure if a big block has more or less room between the bracket and the head than the small block, but they also make these alternators in the aftermarket at 150 amps for about $150. They work really well, very reliable. The CS-130 and later ones have even better idle output, but are a little harder to put on as they have serpentine pulleys.
 
I went with Billet Tech, they have a mopar style if you want it to look OEM. I am using it with a Highway 22 wiring kit, Fuel injection, dual electric fans, in-tank Aeromotive fuel pump...ect. 174 Amp's at 1800 RPM and 146 at 800 RPM...that should do it.
 

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A radiator fan will be the biggest load, and you probably require that w/ a big block. I would start w/ a 70 A square-back (80-90's cars & trucks), since they are cheap and easy. Put it on a charger once in a while, at least every weekend, and see how long it takes to top off the battery at 10A. If <20 min, the alternator is probably keeping your battery charged and the charger just set slightly higher. If it keeps the battery charged, it is doing its only job. Many people don't seem to think that.
 
I had a 78A squareback before I went to the 78A delco 12si. The idle output is quite lacking on the squareback in comparison.

How I would determine if your alternator can keep up is at warm idle with the max electrical load on (fans, fuel pump, headlights, brake lights, etc). If your battery voltage is over 12.8 (which is the voltage of a fully charged battery), then it's acceptable. If it is less, you should really have more output.
 
Besides the dash ammeter, buy a cheap cigarette lighter voltmeter. $15 Amazon or even the $5 Harbor Freight one w/ LED lights. Some people insist that the alternator meets the load at idle. It doesn't bother me if it falls slightly behind as long as it charging >1000 rpm. All I care is that my battery stays charged. You will see the lights dim slightly if running at battery voltage (12.6 V) vs alternator output (14.3 V).
 
Well Bill I already have a nice Autometer volt meter.All guages will be Autometer. Im only missing fuel level and a speedo.
 
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