On Saturday, 18 October 1997 at 22:57, David Brown wrote:
>Just which model of GM alternator did you use--surely
>there is more than one?
You know, I'm pretty sure you're right, ie, that there is more than one
model the GM/AC-Delco alternator, but I'll be damned if I know what the
model number is for the one I used. The reason is that there were not
many physical differences in appearance on these things, at least through
the late 80's -- the same style was used from about 1970 through 1990,
and I think it is still, to an extent, being used now. Indeed, the case
itself is very similar to the case on the externally regulated
alternators used by GM during the mid to late 60's and early 70's.
I believe that the differences in the models of the alternator consist
mainly in how they are 'clocked' (where the position of the plug is in
relation to the mounting points), and the output rating (avaliable in, I
believe, 37, 65, 85, 95, and 105 amps -- the higher the output, the
higher the price).
My 'trial fit' alternator was a 37 amp model. It had no trouble keeping
the system up and charged, but I wanted a little more coverage so I
bought a 65 amp model. What I did was use one out of my pile o' parts
for trial fitting and mocking it up (it came from a '78 Chevy Malibu).
Once I had everything in place, I purchased a rebuilt unit from Western
Auto. This was so I could get one with a lifetime warranty, and be
reasonably assured of trouble-free operation. Because GM used
essentially the same model on so many vehicles, they carried a selection
with good interchangability. Basically, all I did was tell them what I
wanted, and how I wanted it 'clocked,' and they got one off the shelf;
the parts guy told me that if it had been 'clocked' incorrectly they
would have 're-clocked' it for me before I left. I think mine, with the
lifetime warranty, was $65.00. Pretty reasonable if you ask me (and if
it goes out three years from now, it just gets cheaper).
Just some advice here: If you purchase an alternator for this
modification, do it from a chain store like Western Auto, Pep Boys,
AutoWorks, etc (better warranties and they are more likely to try and
please the customer if a dispute occurs). Pick one of the younger guys
(usually a gearhead, and they are much more understanding) and tell him
or her that your Midget uses a GM alternator that was an optional
modification (no lie here, after all, you opted to modify your system),
and that you want an alternator that will fit a 1985 Chevrolet Impala,
with a 350 cid V8, AC, and automatic tranny, that puts out at least 65
amps.
Normally, when they write up the ticket they just put a stock number of
the alternator on the ticket but some places list the type of car -- ask
the parts guy to note that its for a 19XX MG Midget on the ticket because
that's how you keep all your receipts and warranties organized. This
might seem like a bunch of hoops to jump through, but basically it
ensures that if you do have to use the warranty they won't say that it's
not valid because the alternator was used on the wrong car.
The guys at the part store see me pretty regularly so I just went in,
told them that I was tired of having to pay ungodly prices for
unreliable British parts so, rather than having to deal with it anymore,
I was just going to eliminate the problem and convert the car over to an
American charging system, and could they hook me up with what I needed
(an internally regulated alternator for a mid 80's GM, 65 amp). Was in
and out in about ten minutes.
BTW, I looked at a MGB yesterday, and this would be even easier on it.
Luck,
Rich Arnold
Council Bluffs, Iowa, USA
richard.arnold@juno.com
"It is wise to take alarm at the first experiment on our liberties."
James Madison ca. 1791
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