On Thu, 4 Feb 2010 15:51:04 -0800 (PST), Tim
wrote:

It was supposed to be good for 200+ amps but I was never able to get
more than about 150 out of it before the voltage started sagging off.
The local guy here replaced the stator coils with whatever he had on
hand, nothing special it appears, and it now looks like it is good for
about 110 amps or so. *I'm OK with that as long as it is durable. *The
stock Delco that they use in Chevy pickups and Suburbans is rated at
124 amps but the local NAPA place couldn't get one in a reasonable
time.


Wayne, if your alternator is modified to a 'self-exciting' or 'one-
wire' system, that's possibly where your problem was. it seems that
regardless of brand, the SE volt regulators are known to have a
voltage drop where you can't get a good full load out of the unit. or
you need a slightly smaller alt. pulley. (too small is harsh on the
belts, though)

Those items might explain the 150a. before the voltage drop. Or the
builder isn't accurate with their rating claim.

Tim, you raise an interesting issue because it is in fact a self
exciting, internally regulated alternator. On the other hand it
failed prematurely even running at less than rated output so it's
entirely possible that I'll eventually need to bite the bullet and
spend the big bucks for an industrial strength J-180 type with
external regulation. I'll have to re-engineer the mounting bracket on
the engines however to do that.

I think my pulley size is OK because it does reach a point where
increasing the engine RPM no longer increases the alternator output.
I'm running dual Gates XL belts and they seem to be holding up pretty
well.