Smaller alternator

[survyor2]

I'm in the process of doing some custom work around the alternator. For the record I can get the stock altenator to fit but not in an ideal way. I want more clearance in the back. Does anyone know of an alterntor that is not as deep as the stock one? Every millimeter counts. I see there are after market alternators that are "smaller" but i don't know if they are smaller in length. What about other cars? Taurus? MR2?

Thanks,
Dennis

 

[92nsx]

If you only need a couple mm's just take apart your alternator apart and shave the back of it down a little.

As for fining a smaller one, Im not sure of. Pulling from my memory bank (not always correct, lol) I think a MR2 and Viper alternators fit, but I think they are higher amp output not smaller in size.

 

[MarkIII4Me]

Both MR2 and Viper alternators are going to be a good 20% larger than the factory alt. Several months back I bought one of those $89 130amp advertised alternators off of ebay and it's a good 30% smaller than my factory alternator. Bolts up just fine, but just don't expect it to put out 130amps :biglaugh:

These are just test fitting pictures that were taken before I sourced the correct lower adjustment bracket from Sethron. Still, you should get the idea of the size. Also, that is a custom 48mm pulley I had machined. The factory size I believe was around 62mm.

 

[survyor2]

so this 30% smaller ebay alternator...in what direction is it smaller? are we talking about the diameter or length? Can you give me a dimension of the depth?

Thanks,
Dennis

 

[MarkIII4Me]

Don't know exact dimensions off the top of my head. The alternator appears smaller in every dimension. Mostly side to side circumference; not so much front to back. I tried to figure out what vehicle these alternator cores where sourced from, but the only distinguishing marks are an "ND" on the rear cover; which is no help at all.

I can try to take some measurements the next time I'm in the garage; if I can remember.

Still, if your looking for a smaller alternator; this $89 one is probably your best bet.

 

[Clip]

smaller pulley = more amperage?

 

[MarkIII4Me]

smaller pulley = more amperage?

At idle, yes. I've been told the facory alternator only supplies like 15 amps at idle. With my electric fans, piggybacks, gauges and power hungry amplifiers; I'm goin to need too squeeze as much juice outta that alternator that I can. I'm running a deep cycle Optima Blue Top, so I want to keep it as fully charged as possible.

The smaller the pulley, the fast the alternator spins. Of course, once it reaches it's optimum speed it will max out on amperage. However, if you go too small will the pulley you'll desintegrate the alternator at higher rpm. I think they can handle something like 1800rpm before they fly apart. I'm sorta the guinea pig here to see if this baby can handle it. Hopefully my face won't be next to it if/when it goes.

 

[survyor2]

I was able to shave a few things down and i got the stock alternator to fit. Problem is that the fit is so tight, I have no room to tighten the belt by pushing the alternator out. Has anyone added an idler pulley to their alternator belt?