alternators

ok, i'll go take a look at what he's got and if something less than 120amp.

I run a powermaster 140...it makes 80 amps at idle. Runs everything and is overkill....but I like overkill. Only $160

Or check these out:

Summit Racing Alternators

I see where Eastwood ( the auto restoration folks) is selling a nice NEW alternator. $199.99 GM 1 wire style. Apparently catered toward street rods & cruisers. They have a nice video on their site explaning the benefits of it. Check it out before you buy. It may work for you.

rather than trying to explain here's a couple links you should read.
remote sensing
one wire / three wire

We run custom made ones from a local guy.

You take him a junk one or anyone for that matter.

And he gives you back a BEAST!!

They run about 75 bucks.

It keeps my race car at 14.5 at idle with a ton of stuff running.

I have also had them on my competition stereos, and they work well!

i would call some local shops and see how much to build you one.

First thing you need to know is how fast you are spinning your existing alternator @ idle. Crank pulley Dia. divided by the Alt. pulley dia. = pulley ratio. Pulley ratio X idle rpm = alt. rpm @ idle. You may not be spinning your existing alt. fast enough at idle, and installing a higher amp output alternator may not necessarily solve your problem. Which ever alt you buy, see if you can get it with an amp output curve. Most drag race alternators have a very fast rise time - lots of amps at low rpm's. What you are looking for is a combo ( alt.& pulley )that will cover your amp load @ idle - and no more. More than that is a waste of HP. BTW, most of the HP loss is in spinning the cooling fan, not in amps. It can be a real "catch 22" if you are trying to do double duty - street and strip. When you get the alternator spinning fast enough to cover all your accessories at idle, at 6500 engine rpm the alternator is spinning over 20K. The rotor usually doesn't last too long at those speeds. Some typical alternator numbers: Max speed for an alternator = 18,000 rpm. They usually reach max output around 6,000 rpm. Alternators perform best from 2,400 - 6,000 rpm with greatest efficiency around 2400 rpm. Sustained alt. speed of 14,000 to 18,000 wastes lots of HP. Also keep in mind that many of the high output ignition systems around these days are "happiest" at 14 volts. They aint high output at 12 - 13 volts.

This is in the tech archives. Pretty good info there.
http://www.moparts.org/Tech/Archive/elec/34.html

1 wire gm 140amp so far so good

I like the Denso because they can take alot of RPM.
The down side is the larger case sizes (larger amp units) are really deep so that makes them hard to mount on a big block in the stock location. I have a 130 Amp unit from a newer dodge truck. It is external regulated and I had to change the pulley to a v-belt pulley. My pulley ratio is about 2:1. I made a simple bracket to mount the alternator up by the intake next to the distrubitor, this location gives the alternator belt good contact with the pulley. Almost 1/2 the pulley is in contact with the belt, so far no belt squeeling has been noticed. As mentioned the power loss is mostly from spining the cooling fan of the alternator, but if it is putting out alot of current it needs the cooling so the alternator does not burn up.

looks like my ratio would be 2.3 and the idle rpm at 1000rpm would be 2300. thanks for the info,i'll check it out. how are the denso's at idle?

went to the alt/starter shop yesterday. the guy pulled out a denso 80 amp from a 4 runner,rebuilt. pulley is correct and should bolt up without to much trouble. he's looking for an internal reg. to mount inside and let me know. $125 total. what do ya think?

well, i just picked it up. i had him bench test and at idle it has 70amp output and 115amp total when spun up. internal reg. pre set at 14.5v. only requires bat. lead hook up. now i just need to figure what brackets it will take to bolt it up.

That's a lot of juice! Sounds like your good to go. Your ignition system will thank you

Mancini Racing has the correct brackets to hang a Denso alternator on a Hemi, big block or small block.

its mounted and looks nice. did'nt have to buy any new brackets,just had to use an old lower bracket on the bottom where the adjustment is made. i'll try it out tomorrow and see how well it puts out.

alt. works good. 14.3 output at alt. with everything on, 13.3 at the battery in the trunk. 13 going down the road, so looks good. currently charging the battery and will go for a cruise tomorrow.

another.

How many amps are the square back dual field altenators?

Mopar Dave what bottom pulley are you using on the engine? thanks Bradley

i think the square backs are 75 amp.

my pulley kit is a march standard kit. crank pulley measures 5 7/8 dia.

Mopar dave what is the name and phone no of the shop that did your alternator?

super starter shop,flint mi: 810-767-7300. i requested an alt. from a 89-90 toyota 4 runner and this is what i got.

i'v been using a serpentine setup for a few years now and i like them over the v style. this alt. came with the correct pulley and was easy to get everything lined up good.