alternator purchase

You can push start a Model A with a dead battery or even NO battery, but you can't do that with an alternator. LOL

Remember back in high school days when you couldn't afford a good battery, so a bunch of your friends help push start the car for a ride home!
 
VERY TRUE, I can Guarantee you that every rebuilder of a generator would PREFER you don't continually do that , because of what it does to the generator, also why MAJORITY of Generators you open up after much use are very crispy and baked appearing. From the high rate of charge, especially for any length of time, Exactly why it is recommended by anyone in the business to have your battery as charged as possible when putting on any type of unit,
 
That's true, generators and alternators are meant to supply the cars electrical demands and not meant to be used as a dead battery recharger. Where I worked at the yard the guys were to lazy to check and keep the diesel fuel tanks filled on the loaders. When the tank went empty and the engine quit it took a lot of cranking to get the injection pumps primed. Once the two large batteries were almost dead the loader would finally start and a short time later the regulator inside the alternator was cooked. The local rebuilder kept a supply on hand for the yard.
 
I would actually think the stator or diodes would be cooked before a regulator would have a problem but things happen, just as it would be an accurate assumption that if a generator was installed instead of an alternator, The Generator fields and/or Armature would be the often replaced part :)
 
In my experience very few armatures or field coils are replaced compared to internal regulators which I find to be a royal PITA. But, now we're off subject. Why don't we just stay on subject which is Model A's. Model As came with generators, why keep trying to espouse the superiority of alternators. You want to sell alternators, fine, I don't want them shoved down my throat. Most of us here have and are sticking by what came on these monsters.
 
I am still digging up the facts, but my preliminary look indicates there are issues with power transfer.

All the charts stop at a 3" pulley. From what I am figuring off the top my head the V belt on the A into a 3" pulley can transfer on the order of a little over 1 HP.

From other info I have found so far it appears that a 50 amp alt at full output needs about .6 HP.

The amount of HP transfer is non-linear based on pulley diameter. So the smaller you go the much less energy that can be transferred. From another site I am seeing on the order of .33 HP for a larger diameter pulley then what is found on the A alt.

So the math does not appear to support the alt on the being able to output the full rating even with a properly tightened belt. I am still working on the more exact details and anyone can do the same google search and find out. Quick back of napkin calculations are indicating stuff really does not add up.

So Mr Alternator, show me the math. As I am sure you did all the calculations before you put the product on the market.
How much HP does your alt need?
How much HP can be transferred through the pulley to the alt?

Oh and where do your source your alternator from, China?
 
Tom Wesenberg said:
You can push start a Model A with a dead battery or even NO battery, but you can't do that with an alternator. LOL

Remember back in high school days when you couldn't afford a good battery, so a bunch of your friends help push start the car for a ride home!
Click to expand...

You can absolutely push start an "A" with an alternator that doesn't have a battery. All you need to do is get it to spin the alternator fast enough to self excite. Ok so maybe thats 20MPH or so but its still possible. :p

Ok I have the answer that will stop all of the arguments. What is better, an alternator or a generator? Answer : An alternator is a generator so the question doesn't make sense.
 
Patrick, I am not sure why you would find internal regulators to be a major replace part, , That is not really the case at all , Unless you are referring to the Generator regulators. and Not Alternator regulators,, There are many more wear parts as there called , and I would say that I haven't seen an article in the forums concerning the asking about rebuilding a Generator that doesn't mention that there FIELDS are bad/Burnt,
( why keep trying to espouse the superiority of alternators. You want to sell alternators, fine, I don't want them shoved down my throat. Most of us here have and are sticking by what came on these monsters. ) Not quite sure where you came up with this analogy, BUT looking back at the many post of the subject, I believe it is quite Obvious as too WHO is PUSHING anything as your saying , down someone"s throat, and that is quite the Opposite, I have not pushed the sales at all of anything, only exchanged information and defended an option, and presented factual comparison, YOURSELF have in fact have went out of your way in many inaccurate ways to attempt to discredit, Alternators and promote generators and newly added accessories to it,, is it for the names of people you continue to add in your posts selling these products ? or your own gain?, I am not sure and would guess others know the answer concerning that,
 
OK guys...........cool your heels and read what Audel's has to say about generator's and alternators. :D For those not familure with Audel's, they have written excellent books on electrical devices and go into much scientific detail. You can find Audels on ebay or sometimes in a used book store.
Anyway, I got a kick out of this:
 

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Tom Wesenberg said:
OK guys...........cool your heels and read what Audel's has to say about generator's and alternators. :D For those not familure with Audel's, they have written excellent books on electrical devices and go into much scientific detail. You can find Audels on ebay or sometimes in a used book store.
Anyway, I got a kick out of this:
Click to expand...

Nice.

Problem is now many people may wonder "but why does a DC system have an AC generator?"

I believe the answer is because an alternator has slip rings instead of commutator bars and it allows far greater current to pass through the brushes. There may be other reasons as well but I am unaware of them. So you take a 3 phase AC generator, throw some diodes on it and bam, you have a very efficient DC generator. :)
 
Well, there is always one or two in every crowd. I'm sick of this. When dealing with people like this I usually just nod my head and back away slowly. You probably can't see it, but, I'm backing away quickly.
 
More info....A generator uses the commutator and brushes to convert the induced current into DC. The alternator uses diodes to produce DC.

The generator uses a fixed magnetic field, the alternator uses a rotating magnetic field fed through brushes, BUT, the brushes rub against slip rings, not commutators.

That's why the alternator's brushes last longer.

Marc
 
Tom Wesenberg said:
OK guys...........cool your heels and read what Audel's has to say about generator's and alternators. :D For those not familure with Audel's, they have written excellent books on electrical devices and go into much scientific detail. You can find Audels on ebay or sometimes in a used book store.
Anyway, I got a kick out of this:
Click to expand...

Holy Kamoli.:confused: Good one Tom. It looks like this thread could use a touch of humor. :p
 
Bob,

You mean like "what oil should I use" "antifreeze or just water?" "leaded or not?" "6v or 12v" ?

I may be forgetting a few but those are the horses I see a lot.
 
I have an alternator on my A and the belt is set to where I was told to put it by the vendor (Ken Davis). I am able to grab a fan blade and just barely spin the fan pulley under the belt (meaning the belt does not slip and the crank does not turn, only the fan pulley turns with some minimal effort.)
I hardly consider this a super tight belt.
I wonder why this works just fine on my rig when everyone else says the belt must be tight as the dickens.
There is no abnormal wear to the belt and the alternator works just fine. Stop by and see it in action.
 
I have never implied that an alt is better than a gen,but for the low current draw of a stock A,an alt is simply not required.By the 60,s the electrical demands were much higher,so alts & 12 volts were required.If running AC & other high draw accessories are added,then it should be obvious that 12 volt neg ground is required.Have all wiring
In tip top shape with soldered connections & clean grounds & it will crank over more than fast enough to start.
 
In my last post I should have said that a gen is not better than an alt.This will be my last post on the subject !
 
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