jerry gollnick

I'm planning on using my 61 for road touring events and since many are in warm places like Arizona and Texas it seems like vintage air is a good idea. Motor is a 350 with stock radiator. Any of you ever use a generator with this setup? Do I need to switch to an alternator?

Frankie the Fink

I've seen it installed on a '62 with a generator and the owner claimed there were no issues; even here in sunny FL. You might just try it and see if you can get by with it. You can always add an alternator later on..

Easy Rhino

Disclaimer: I have not owned a generator-equipped car in a long time, never a generator-equipped Corvette, or a generator-equipped car with A/C; however, the main concerns I would have are (1) what is the amperage rating of my generator intended to be used with A/C, (2) how many amps does the A/C draw, and (3) what are these answers for the most severe condition, i.e., at idle in hot climates with a full A/C compressor and blower loading?

My concern would be what I think is the same as yours - how low will the voltage drop, and high will the amperage get under these conditions, and will the I2R losses be excessive, leading to wiring and electrical component heat damage.

Since the C1 was not offered with A/C, are any generators on the C1s capable of handling the load? I don't know.

jim lockwood

Passenger cars of the era, which did have generators, did come with air conditioners (optional, of course). Generators for cars so equipped were 30 Amp models.

Jim

Easy Rhino

I happened to pull my Corvette numbers book out and it shows that originally 61s came with either 30 or 35 amp generators.

For 1963, the first year for optional A/C, the alternators were 37 amps for the base car and 52 amps for the A/C car. That's quite a difference.

What I cannot speak to is how many amps a vintage air system requires as compared to an original GM system, but it would seem that the GM engineers concluded that the original A/C systems needed around 15 amps over the non-A/C cars.

And yes, I am probably overthinking this, but it comes naturally to an electrical engineering type.

Recall that a major reason for manufacturers transitioning from generators to alternators was that generator output tended to fall off at low revs.

jerry gollnick

I called vintage air and they said a 35 amp generator won't work. They recommended no less than an 80 amp alternator. Their system uses 18-22 amps . What do you guys think?

DZAUTO

As Jim pointed out above, early cars did in fact have have AC with generators.
Within GM cars, Buick, Olds, Cad upgraded to 12volt systems in 53, and AC was an option on all. Pont got AC in 54 (but still on 6v) and Chevy got AC in 55 along with an upgrade to 12v. GM cars used generators on ALLLLLLLLL models up through 62 (some 62 Chevys with AC got a primative Delcotron alternator).
I clearly remember my Dad's 55 Olds with AC and I don't recall him ever complaining about having generator problems.
Now, with all that said, the early GM AC systems pulled much more amperage than is required for today's add-on aftermarket AC systems. The main electrical load on an AC system is the clutch for the compressor. Today's compressors/clutches are a significant improvement over those from the 50s-60-70s, thus, I would expect a 30-35amp generator --------------------------IN TOP CONDITION, should be fine. And make sure you have a GOOD voltage regulator!!!
Also, when wiring in the AC (blower and clutch), I'd think a heavier wire gauge would be very beneficial.
I have long comtemplated adding AC to the 56, but I've just never been able to cut the required holes for the plumbing (YA, YA, YA, YA, YA, I know, I did cut a hole in the radiator support for the airbox).

Easy Rhino

Wow, 80 amps is a lot, considering their unit is claimed to use only 18-22 amps.

If you have a 30-35 amp stock generator, and you need to add approx. 20 amps, then 50-55 amps should be plenty, so I don't grasp the 80 amps recommendation. Perhaps they are considering a car with all the other power hungry accessories such as big stereos and lots of lighting?

Nonetheless, finding a 50-55 amp generator is much more expensive than installing an alternator, not to mention lighter and smaller, so if it were mine, I would add the alternator at the same time as installing the A/C.

You could always try Frank's idea first and see if it will work; however, that might mean additional costs and effort to change the pulleys and brackets out later if you wind up having to have an alternator.

kingwoodvette

Vintage offers an auxiliary fan that mounts in front of the condenser for improved a/c function and engine cooling at slow speeds. The 80 amps recommendation may leave room for this additional amp draw.

DZAUTO

Oh ya, I should have mentioned this.
In 1966, I converted my 51 Chevy ti 12v, changed to an alternator ------------------------- 37 amp------------------ and installed a USED, ugly, under dash air cond unit. That 37 amp alternator has been rebuilt ONE TIME since 1966!!! It has always handled the load just fine.

Frankie the Fink

I don't know who you talked to but:

1) None of the installation guides mention having to swap out a generator for an alternator, and,

2) 80 amps is a ridiculous figure...way too high for an aftermarket A/C unit.

My original '63 alternator was internally upgraded to 70 amps (mucho overkill) and never even breaths hard with EVERTHING (including A/C) in the car maxed out...

jerry gollnick

I talked to their tech guy.
Can an upgrade be done to a generator to give more output?

DZAUTO

Jerry,
Over on the Chevytalk forum, one of the members (Jalapeno- his first name is Steve) can upgrade a generator to about 40amps. He is in the Dallas-Ft Worth area.
rpo324@sbcglobal.net

Easy Rhino

A generator can be upgraded, but is more limited than alternators, in total amps, and more expensive.

DZAUTO

I have ZERO argument with that. BUUUUUUUUUUUUT, for the person who wants to retain the semblance of the original generator/engine compartment, that is an alternative (SOOOOOOOO, how does one retain original engine compartment appearance of a 53-62 Vette with an AC compressor bolted on???).

Easy Rhino

I hear you on that. His car, but if I'm installing an A/C compressor in a C1, I probably don't care about keeping a generator, and go for the alternator anyway. But it's not my car.

Frankie the Fink

That's fine except you all are missing the fact that most C1 tachometers are driven off the generator so its not a straight forward swap to an alternator. There is a company that makes generators into hi-output alternators. Its expensive and they don't do tach drive generators (I've talked to them): http://www.gener-nator.com/

Easy Rhino

I was wondering about that, but I am not familiar with that set up.

DZAUTO

Just for added information, there is (or was) an alternator ---------------------- AT ONE TIME-----------------which was used on farm tractors that had the SAME splined amature shaft on the back of the alternator. YES, I have personally seen one on a 57 Vette!!! One of the NCRS guys in Tulsa brough his 57 to a cruise-in and it had such an alternator. I have a picture, but I swear I cannot find it!!!!

FOUND IT!!!



This is not the best picture, but it's the only one I have.

dplotkin

They did, but GM would run flex hose from the rad support to the back of the generator to increase its output. My 60 Buick has that & so do the Caddy's of similar vintage though most have been lost.


GM cars with A/C and generators also used a double contact regulator which can be destroyed if the field terminal is grounded (as in full fielding to test output).


It is the blower fan that draws the largest load, then the clutch. So the problem is that generator output is low at idle (and the cutout typically open) and in hot weather and stop and go traffic an A/C car with a generator using its lights, wipers and fan on high would run out of juice.


This drove GM to move to alternators in 62 on A/C cars on most of its line. It was the reduction in cost of solid state diodes that made the alternator practical. Some of you older guys might remember the cop cars often ran Leece Neville alternators with externally mounted selenium rectifiers. That allowed them to use their lights, radios and other "cop" stuff at prolonged idling without killing the Battery. I have a 63 Galaxie (no alternator until 65) with factory A/C that comes standard with a manual throttle pull **** to speed up the engine to turn the generator fast enough. Alternators were a big improvement.


Dan