RatDog

My '67 has its original alternator. I've made the following recent changes to my car's electrical and ignition systems and am wondering if I should think about replacing/upgrading the alternator:

1. Replaced points with a Mallory Unilite conversion kit
2. Replaced voltage regulator with a solid state unit
3. Added Vintage Air
4. Replaced radiator with a Dewitts with a built-in SPAL fan

I don't know the amps of the original alternator. Should I go with an alternator that has a higher amp rating? If I do that, should I be concerned about the car's wiring and other electrical components being able to handle it?

If it makes sense to upgrade the alternator, I'd welcome recommendations for a specific model and vendor.

Thanks,
-- Steve

66BlkBB

Steve,

Doesn't the case have the amps stamped on it?? Most of them do. Are you sure yours hasn't been replaced with something else. My 66 came with a 42 amp unit. That was without air or any other electrical, ie. pw, etc. I thought that cars with AC came with 55 amp units to cover for the extra needed. Could be wrong. Someone will correct me if I am wrong.

RatDog

You are correct, sir. It says 57 amps, barely readable, but it's there. My car didn't come with a bunch of extra stuff either. But PS, PB, Vintage Air, radiator with SPAL fan, and electronic ignition stuff has been added to the car.

Is 57 amps enough? How can I tell if the alternator is original to the car?

Thanks,
-- Steve

Mike67nv

The standard alternator in a ’67 small block without AC was a 37 amp unit, with AC, it was 55 amps. Small blocks with transistor ingnition, went to 42 and 61 amps respectively. With your added electrical draw, a higher amp alternator would be in order.

Tampa Jerry

Like you, I added A/C, and a pusher fan. I also converted my radio to a 150 watt output. With that said, I added a Power Master 100 amp. alt. with an internal voltage regulator. In fact, I did the same conversion on my 68 small block coupe also. Jerry

Powershift

Factory wiring should be good for a 55-61 amp alternator, since that was what was available originally. This should be good enough for you. Your amp gage should tell you whether you are still able to charge the battery with everything running.

Installation of a higher output alternator than 61 amp would need a wiring upgrade to be safe. Not all wiring would need to be changed/upgraded. An inline fuse or fuses can also help protect original wiring.

Larry

Sky65

I too am using a 100A Powermaster alt. I added msd box and dist, amp for the radio, and expect at some point will change over to electric fan and perhaps heated seats. I wanted to be ready.

Tom

RatDog

Further inspection of my Delco-Remy alternator reveals a date code of 7F14 which I think would be June 14, 1967. My car was built on July 12, 1967 so I'm thinking it's the original alternator to the car. I also found the 37a stamping so it's a 37 amp alternator which probably is not enough to run all the add-on electrical stuff.

I don't know what the other stamping is. It's either 57 or 67 but is very tough to read. Looks more like 67 and is probably indicates the model year.

I'll take a drive later today and load it up with A/C and headlights on and see what the amp gauge shows

-- Steve

Sky65

You may be able to have your alt conveted to a higher output if the dates matter to you but I would think you would want/need more juice.

Tom.

Mike67nv

The markings on an original ’67 - 37 amp alternator should look something like the pic below. If you have an original …693, don’t throw it away!

RatDog

Yes, it looks just like that (but not as pretty as the one you're showing) and it has the digits "67" (or maybe it's "57") stamped in a larger font in that empty space to the left of the other stamping.

Original or not, I think it's coming off. I agree with others . . . I don't think 37 amps is going to work. I'll bag it and hang on to it.

-- Steve

Mike67nv

A local rebuilder should be able to upgrade the amperage of your existing alternator (and rebuild as necessary) if that appeals to you. I had talked to my local NAPA store a while ago and they offered that service here. Your local FLAPS should have an over the counter replacement with higher amperage or you could go with one of the more expensive aftermarket brands. I would guess something in the 60 amp or higher range should do.

RatDog

Thanks Mike. My carb and my radiator are not original to my car plus it has add-on PS, PB, and A/C so I'm not thinking of originality.

I've been looking at some rebuilt Delco-Remy 61 amp alternators online. One of those should appear correct to the casual observer so that's all I'm looking for at this point.

-- Steve

Powershift

If your alternator has all the correct GM numbers etc like the example PLUS an additional 56 or 67 stamping on the case, it may already be rebuilt and upgraded. You could remove it and bring to an alternator/generator repair shop and have them check the current (amp) output.

If it has the correct part number and date, I would at least keep it rather than turning it in for a core.

Larry

RatDog

Good advice, Larry. The replacements I'm looking at don't require a core so I'll be hanging onto it.

-- Steve

GreaseMonkey

Running a 100A Powermaster alt.

RatDog

I took the car for a short drive with headlights and SPAL fan running (but not the A/C). The ammeter needle was about 1/2 way over to the charge side while driving and dropped back down to the center when idling back in the garage.

Don't know if that's good or bad but I decided to change out the 37 amp alternator for a remanufactured Delco 55 amp alternator from ZIP. Went ahead and got their solid state voltage regulator, too. I'll keep the points VR in the car for a backup and I'll hang onto the old original alternator for the next owner.

I'm assuming from what I've read that this alternator and VR will play nicely with my new Mallory Unilite ignition kit.

Am I correct that I no longer need the radio capacitor when I put in the solid state voltage regulator?

Thanks,
-- Steve

MidYearRoadster

If I am not mistaken, the fans alone when on will draw over 30 amp. now figure in your AC ..and stop and go traffic...save the alternator you have now and go for at least an 80 amp alternator..why take the chance....

wmf62

i'm using a 140 amp 12si alternator.
Bill

Ironcross

the guts of a 94A alternator should fit your case and end frame/housing if a good rebuilder is available in your area....no one would know the difference....we use to sell the best starters and alternators available anywhere