Alternator overkill?????

[Fat Hack]

Okay, I can hook wires up and make stuff work (usually), and I've wired cars before...but I still can't figure why people go ape-shit when buying an alternator for their rod?

You always see a T-bucket running a 100amp chrome alternator way up there for all the world to see when his electrical accessories consist of headlights, brakelights, tail-lights and maybe a radio in addition to the starting/charging/ignition systems.

Seems to me that a generator or a standard alternator oughtta be able to carry such a small load! Is there a formula or rule of thumb to use when selecting your charging device for a given vehicle?

I know alot of people think "bigger is better", but really...having a 100amp alternator on most rods is like building a nuclear powerplant to supply electricity soley to the guard shack in front of it!

(Of course, if you have neon lights, a 50 CD changer, subwoofers, air conditioning, cruise control, power windows and all that crap...then you NEED all that ooomph!!)

Also...are 6v and 12v generators interchangable, and what's different if not??

[Deuce Roadster]

http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif


I had a 37 amp alternator on the 32 roadster......no radio, heater or anything else electrical
The headlights would dim at idle....sitting at a traffic light..
Put a 62 amp on.......
No lights dimming now.......

I do have halogen bulbs....front and rear http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif




http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[Machinos]

100 amp alternators are pretty much "standard", I think the lowest you can get from most rod supply places is like 85... and strangely enough, the chrome ones seem to cost the same as the plain ones.

I think 6v and 12v are usually interchangable, I know on Mopars for example you can convert a '55 to 12v easy if you have a '56 parts car. The downside is that it's still positive ground, and it's still a generator which means it's quite a bit heavier and you have to keep it tuned up, and it might not give you enough juice to keep the system charging at all times even if it's stock. My car dips down past the break-even point on the ammeter if I'm letting it idle in drive (auto trans of course) with the brakes on. If I've got the high beams on which I usually do since the regular beams are pathetic, I've gotta put it in neutral at stop lights or they dim out and it starts suckin' from the battery.

[safariknut]

I still have a generator(35A)on my Safari only because I haven't found a good mounting bracket for my alternator yet.I have halogen headlamps(60/55W H-4's)that draw 10 amps alone and at an idle it is always discharging.With the lights on,it just about pegs the amp gauge.I don't have A/C or even a heater motor that works,my wipers are vacuum(inoperative),my radio has a minimal draw.Luckily I have a behemoth battery that rarely goes dead(unless I leave my lights on.Alternators make sense.

[flatheadpete]

I went all out and put a 12 volt generator on my flathead T-bucket. Only has to run ignition and lights. (It's got a 6-pipe wide open stereo; no wires there!!)

[Missing Link]

Why do people go ape-shit? Because some genius decided that using a 1-wire GM alternater for every application would be a good idea. So good that the aftermarket basically offers only chrome plated 100amp versions. On a side note, I personally can't bring myself to spend $80.00 for a chrome plated alternator when I can go to the local NAPA and get a plain one for $45.00
From my experience, GM 1-wire alternators are not that easy to find. I searched high and low in my area at the local parts shops and not a single one carried a one wire unit. But the two wire versions are everywhere. Wow, I need to run a second wire now. Oooh, scarey. PUAR! If you are in the middle of a rewiring project it doesn't much matter if it is one wire, two wires or thirty wires anyway. I was thinking about availability of parts when I put an alternater on my flatty. I was also thinking about how many power options I currently have and what may be added in the future. So I figured....
Why run 100amps when 60amps will be more than enough. I don't have many power options (AC<---in a hot rod? no f'n way!, power windows? nah..., stereo-probably over the winter) That however is my situation. Other scenarios will vary depending on accesories. But running 100amps on a vehicle that doesn't need it is not a good idea anyway. One more fusible link/by-pass to go bad and create more problems. 60amps is capable of running quite a few add-ons anyway. A key idea when deciding what size alternator you need is to estimate how many amps will be drawn when every electrical option on the vehicle is on. Size your alternator by amps accordingly.
The 6volt/12volt generator is a moot point in my opinion as parts are not easily found for these items. Most people using generators will have parts for them laying around, but on the road these items are scarce. That was my main reason for switching to begin with. That and the fact that the 6volt system in my car sucked. Interchangability? I really don't know. Although I do know that you can have a generator converted from 6volt to 12volt. Keep in mind that generators spike much higher and more often than alternators and most good wire harness manufacturers will recommend that you do not use a generator with a new wire kit.

[manyolcars]

_link_ sez-----From my experience, GM 1-wire alternators are not that easy to find. >>>>> You dont FIND them, you MAKE them. The starter repair shop sells you the self exciting regulator for $6, you install it. Its easy, dont be afraid http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[porknbeaner]

The easiest way to figure out what ya need in the line of amp output is figure the amp draw of all your accesories (look up OHMS LAW) then add 10% (a nominal number).

I run a 1 wire GM on my rod (now a project) because that's what I had when I was putting it together. It was 65 amp to start with and that was plenty. I fried the regulator and upgraded to 105 amp, not because I needed the extra amps but the kit was cheaper than a regulator/rebuilt alternator.

When the new ride hits the road, it'll be running a one wire chrome (70 amps). Not because I really wanted a chrome alternator, or even wanted to change my amps. A friend gave me a new one, said I didn't have enough chrome. I hate chrome, not sure why.

I never run one up high unless I have to. It just a mater of personal preferance.

I have a late model (metric) 90 amp from an S-10 in the shed, the truck it came off of was a plane jane, 4 cylinder, didn't even have a radio. Who knows why it had such a high zoot alt. Probably never use it, they have a tendency to over heat. But... ya never know.

If you're gonna run everything in the world electric you need a high zoot system, otherwise its overkill. Unless of course that's what ya got. For me the name of the game has always been run what ya brung.

When I was in High School and generators were the norm we used to upgrade the 6 volts by changing the fields to 12 volt. Then change the regulator. It was sup[posed to be better, but... I don't recall that positive ground was ever a problem, but memory is selective.

if it don't make ay dirty it aint yours http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[Paul]

I run the chrome one wire 85 or 90 amp

because my custom/rat/death/hot/STREET rod has an electric fuel pump and an electric fan and some day will have; headlights, wipers, heater fan, tunes and whoknowswhatall.

I just wanna be ready.. http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif

Paul

[CruZer]

I run a 100amp alternator because at idle at night with the halogen headlights and my electric fan on ,I need it !!!!

[Missing Link]

[ QUOTE ]
You dont FIND them, you MAKE them. The starter repair shop sells you the self exciting regulator for $6, you install it. Its easy, dont be afraid


[/ QUOTE ]

You are 100% correct MOC. I agree it is not hard to convert an alternater to a one wire unit. However, I look at it this way, why modify an alternator when I can just run a second wire that is supplied with the harness? The pernt is, if the alt takes a dump out on the road some where, I for one will not want to shit there trying to convert an alternater to one wire. One wire alt's are a great concept and work perfectly fine. I just prefer using something that would be quick and easy to fix if needed.
Not that I am trying to start an argument manyolcars, I am just explaining what went into the decisions that I made when it came to an alternator selection.
http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif

[LaGrasta]

www.madelectrical.com (http://www.madelectrical.com)

try this place for answers. they have some great kits and they hate 1 wire alternators

http://www.madelectrical.com/electricaltech/onewire-threewire.shtml

[Lucky Strike]

www.madelectrical.com (http://www.madelectrical.com)

try this place for answers. they have some great kits and they hate 1 wire alternators

http://www.madelectrical.com/electricaltech/onewire-threewire.shtml

Thank you for this link! I have learned a thing or two just reading their website.