alternator question

[Greg L.]

What determines the amp rating, the stator windings, rotor(field) windings or a combination of the two? Can you mix and match rotors and stators with alternators of different ratings or do I have to use a 42A rotor with a 42A stator?

[Joe L.]

Re: alternator question

Greg-----

The rotors are, basically, the same/interchangeable for all alternators of a given series (10DN, 10SI, etc). Rotors are NOT interchangeable AMONG series, though (i.e. you can't use a DN series rotor in a 10SI alternator and vice-versa). The component most responsible for the difference in output ratings is the STATOR. The 37 and 42 amp stators are the same, though, and the 55 and 61 amp stators are the same. You can generally use any rotor (within a series, of course,) with any stator (within a series, also, as stators are NOT interchangeable among different series alternators, either).

All 1963-68 Corvette alternators are series 10DN. All 1969-76 Corvette alternators are series 10SI. Some 1977-82 Corvette alternators are series 10SI, some are 12SI, and some are 15SI.

[Greg L.]

Re: alternator question

Thanks Joe,

That's the info I was looking for. Would you happen to know if there is any physical difference in the rotors so that one could tell which series alternator they belong in?

[Joe L.]

Re: alternator question

Greg------

The rotors for the DN and SI series alternators are very similar in appearance, but they are not interchangeable. I believe that one of the differences between the two is that the shape of each segment of the "interlocking triangular magnets" is a little different. The SI series has a radius at the top leg of the triangle; the SI series is "straight" across. However, I'm not 100% sure of this. It's a vague recollection.

[Greg L.]

Re: alternator question

Thanks Joe,

I'm just trying to piece together the alternator for my 69.

I found a back case and by some miracle the parts car for my 70 Judge had an open faced front case alternator on it but for some reason it never got stamped so it looks kinda funny with no numbers. Anyways, from what you mentioned, I should now be able to make it all work without too many problems. Thanks again.

[Gerard F.]

Re: alternator question

Greg,

The basic difference, I found, in the stator between the two series Joe noted is the gage of the windings as well as the pattern of the windings. The 55-61 amp alternator stator has a heavier gage winding. The rotor and stator combination both fit the case between the series, and I think you should keep them together.

I took the rotor and stator from a supposedly 60 amp replacement alternator for my 67, and put it in the case of my original 37 amp alternator. Works just fine. Although I'm not sure what the amp rating is, it's a lot more then the output of my old 37 amp.

Jerry Fuccillo
#42179