Ford Alternator Suggestions

[CraigMBA]

Does anybody have any suggestions for Ford application alternators?

I have a big case externally regulated unit on right now, which is a big step up from the stock small case, but it's still pretty marginal at idle. Plus, it's huge. I bought a 16" SPAL fan this week so we all know where this is going.

I'd have a preference to do OE Ford unit but I was curious if anybody had any experence outside of The General.

[CraigMBA]

Found it. G3 it is.

http://www.2mfffabshop.com/miscpic/3Ginstall.jpg

[BoBo]

I just replaced my bronco altenator last month. It's a one wire set up which is extremly easy to install. Don't know what your price range is, but I got this altenator...
PWM-8-47140 Powermaster Street Alternators
Alternator, Internal Regulator, 140 Amp, Natural, Ford/ Mercury/ Jeep, Each
Today$159.95
through summit. Don't quote me on this but I think stock is about 65 or 70 amps. I have had an amp with 12'' speakers, brights on my truck, and the brights on the plow and it stars in -10 f temps no problem.

[fast Ed]

The 3G alternator conversion works pretty well in most classic Ford applications. We're going to do it on my Cougar this spring, so I can run an electric fan. They are commonly available in 95A and 130A versions.

The nice thing with the 3G, is that it will often go on to the original 1G alt. brackets. We've mocked it up on an engine for my buddy's 67 Mustang project, and it is going to be a pretty straightforward swap.


cheers
Ed N.

[MonzaRacer]

Hmm so you seem to have problems with electric fans and a big alternator.
I ran electric fans on a 55 amp 10SI GM alternator and my fan would run for 15 minutes after shut down and I never had any battery problems.
As for problems you really need to make sure use the newer electronic regulator. NAPA number I believe is VR749, Look at later 80's Ford cars/trucks applications.
I have been running electric fans and not had super high amp alternators.
If your fans have good relays and good heavy wiring straight to battery with a good fuse inline you dont need high amp alternators.
Now you do need a good high capacity battery and so far I have had good luck with Interstate , Duralast Golds and optima.
I have ran mostly Interstate for the lat 12 yrs and before that I had Diehard Gold(it andthe Duralast made by Johnson Controls) and a couple years ago I bought a blem optima and it had performed admirably.
If you have a car running more than a constant 45 amps running down the road something is wrong. I had a CSI144 (120amp) alternator (GM) and even with electric fans, a 360watt (2 10" subs and 2 6x9 )stereo and CB ,ignitions lights etc and I rarely saw the alternator output go above 35-40 apms and this was usually with heavy base line Cd in and playing.
My car never left me stranded from discharge, I had left my lights on many times, sat with stereo playing for hours on end and still started my car.
Use 2/0 welders cable for battery cables , groud the crap out of everything with good quality stranded stainless ground straps and a good heavy 8 or 10 guage feed wire and make sure it feed directly to the power junction or battery.
Proper circuit construction will keep you from having major problems and if you arent sure of the wire size go up a size.
A good battery and a fresh alternator will keep you going strong. I have several cars out there that I wired with stereos, electric fans, fuel pumps, improved ignitions, and many other accesories and even the current OEM cars rarely have over 120 amp alternator and they sure have a lot of addons and never need super high amp alternators.
Now if you add on 1000wat stereo or even more you may need some add on power.
I do electrical diag and repair and there are a lot of falicies out there and i have driven the cars I built wiring systems for and never had to go to rediculous extremes to power them.
If you hear the engine rpm dip when a accesory comes on THIS IS NORMAL. It is the alternator adding currnet output to keep the battery voltage at a regulator determined level.
If you have a big case (I hope a high amp) alternator then you should be ok. Dont forget get the later model regulator it short circuit protected and it has better suppression internally and I generally find it holds up better.
Fix the basics then if you find deficiencies add/repair the system.
Lee

[CraigMBA]

Monza,

I hear what you're saying, and your not wrong. But that's not my issue.

The problem is idle performance. The alternator can be rated at 10,000 amps but be zero at idle. What I need is 13.8v at idle, and a stock 1g Ford alternator is hard pressed to get there at idle if you full field short it. At 1500 RPM's, no sweat. It's 18 volts!

My big case works okay, but it's HUGE and looks horrible. I've got a high zoot external regulator like you're refering to. 13.4 is all she's got at idle. Toss in AC and a new 20a draw from this fan (I borrowed a customers current meter and hooked up the SPAL fan to a battery) and I'm in bad shape. Assuming I keep this piece, my only option is to drive the car around with a 1,500 RPM idle and have a grip of voltage.

All the late model stuff works at idle and I'm looking for suggestions if somebody's got them. Like, the 90 amp units have better idle performance than the 130a units or whatever.

[Eurostang]

Pulley Size? adjust the pulley size to get the Alt rpm you want!

[TheJDMan]

I agree, it sounds like you just need to speed up the alternator relative to the engine speed. I installed a brand new 145amp Power Master 12SI alternator on Dust Off. Worked great, was able to remove the external voltage regular. But at idle the voltage would drop back to close to battery voltage. I installed a smaller diameter pulley on the alternator and the problem was solved.