<VV> Uprated Alternator?

[James Davis]

I run a 80 amp 12SI alternator in the Ultra Van and draw about 40 amps out 
of it during normal operation (lights, oil cooler pump, fans for trans and 
oil coolers, refrigerator, and ice maker)   With a 3.89 rear gear, the 
cruise rpm is about 3,400, so the fan is drawing another 6 hp.  Since a 
"vee" belt transfers power by wedging itself into the pulley's groves, the 
more power transferred, the greater the heat due to the wedging friction 
and incremental slip cause by the wedging.  The heat generated in the belt 
softens the rubber and further increases wear.  I find it prudent to change 
the fan belt every 10,000 miles when I change the oil.  Conversely my air 
conditioned Rampside with gasoline heater with a 105 amp 10SI alternator, 
and with a cruise rpm of 2,700, gets a fan belt every 40,000 miles or 
so.  It is seldom I draw more than 20 amps from the Rampside alternator.
If the single wire from the alternator to the load is of sufficient size, 
the third wire is superfluous on a one wire.  I, like you, prefer big wires 
and fuses.  I do agree that the second wire to the regulator, for the 
charge light, is necessary even with a one wire regulator.  Not only does 
the light indicate if the fan is operating, but is drops the alternator 
cut-in by 1,000 rpm or so by energizing the field through the light circuit.
Jim Davis

  At 08:31 PM 5/31/2005, JVHRoberts at aol.com wrote:
>
>OK, I'll do this one at a time, based on my experiences.
>
>1. I've never noticed an increased frequency of belt failures, even with a
>72 amp 10SI conversion.
>
>2. Skip the single wire types, too many issues and problems with them.
>Besides, you WANT that light for thrown belts!  Stick with 10SI internally
>regulated types. IF you were adventurous, find a way to adapt a CS130 to 
>a  Corvair
>front housing. GOBS more output at idle, and no dimly glowing 
>idiot  light! But
>probably more than what you want to get into.