5.7 Alternator ???

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joeboy

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Has anybody using the "car" timing cover been able to find a ALT that will fit without modifying the Passenger frame rail? I have seen pics in post that it looks like it clears, but mine isn't close. If so, got a part #?


JOE
 
From what I've read on this forum, there's a big difference between the early and late A bodies as far as clearance.
 
X2

The frame rail trim isn't that big of a deal. Assuming the engine is out of the car you have plenty of room to work.

Regards,

Joe Dokes
 
mines a '67, I know I got more room than the early guys do for sure. I was just curious if anybody hasn't had to modify the frame rail, (like trim the spot-welded lip off) I have seen pics on here of some members swaps that seem to have good clearance,and was wondering what ALT they used... I have the motor in the car, and tried to mount the ALT today but mine is a NO GO without grinding...
 
Gdemon is the one I recall who didn't trim. He used a jeep grand Cherokee alternator. Thats going to be your best bet. It mounts in the same general area, but differently. Same front cover.
 
I am liking this alt mounting and would like to know if it's custom or if its a kit and if its a kit who makes it.
 

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I have a 73' Duster with the car timing cover, and the car alternator, has plenty of clearance. Also, using the RMS front suspension.
 
Thanks for the help, just gotta find the right combo... I will be trying diff ALTs... I think Gdemons was the one I remembered. I have a grand cherokee ALT currently, maybe I will try a car one before I do any choppin (cars already in paint, so I really hate to)

May try to "re-position" the motor a bit too, it is real close...

JOE
 
I didnt want to start a new topic, so thought to ask here about how do you people route your wiring, which kind of voltage regulator you use and how much voltage the system is charging?

I have been strugling a while with my charging problem, first one connector of alternator to battery was corroded inside and the current didnt pass that fully, causing the alternator blow a diode and regulator pop.

Then I renewed alternator and regulator, rewire new very thick cable directly to battery, check the ground of voltage regulator and also add a extra ground cable from it. System was charging steady 14.7V all the time and worked fine 1500 miles, then suddenly start to charge 17-18 volts and regulator finished again. My wiring is like the Mopar Performance tells on crate engine instructions, blue cable from ignition on, in the middle of regulator and to the other field of alternator, green on other field and side pin of regulator.

I talked with one car electrician and he thought that maybe the resistance of rotors is bigger and old regulators can´t handle it. But I never seen nobody to telling similar problems...I have a 2005 truck hemi with 130 A alternator on my car.

I would appreciate good advice...:prayer:
 
The voltage regulator simply turns the alternator on and off, no substantial current runs through the voltage regulator.

On a standard three wire alternator you have two field wires and one power wire, or output wire. With a modern 130 Amp Alternator with the right type of wire insulation you can run a wire as small as 6 Awg, most of the wire you are likely to buy at the auto-parts store may not have the high temp insulation so to be on the safe side run 4 Awg. wire, as even the poorest insulation on 4 Awg. is sufficient to carry 125 Amps.

Traditionally on a Mopar this single power wire would run through the bulkhead connector, through the amp meter, and then to the power distribution block. The full output of the alternator is passing through the bulkhead connector and through the amp meter. This arrangement was marginal in the 60s with 40-60 Amp alternators, it is a fire waiting to happen with a modern 130 AMP alternator.

You can run the wire a number of different ways. One possible way is to run a 4 Awg. from the alternator to the post on the battery. Another possible method is to run a 4 Awg. wire from the alternator to the power post on the starter and then another 4 Awg or even 2 Awg wire to your battery. (I would only recommend a 2 Awg wire on very large high compression motors, 2 Awg is a pain to work with and largely overkill).

As for wiring the alternator itself, your standard 60s era voltage regulator which was an electro-mechanical device has been replaced by a solid state device. (The ones in the sixties actually had something resembling points that you could visually watch open and close. Today, this turning on and off is done with a semi conductor and thus there aren't any moving parts which makes them more reliable.) If you happen to have the old 60s era voltage regulator fear not as no substantial current travels through the regulator it will work fine even on a 140 Amp alternator.

The key to understanding how a voltage regulator works is to see the voltage regulator as an on/off switch, it simply switches the alternator on and off. When 12 volts is supplied to one the alternator field posts, and the other field post is grounded the alternator charges. When the ground is removed the charging stops. So by grounding and un-grounding one of the field wires the alternator is able to cycle on and off rapidly to maintain a relatively constant 14-15 volts.

You'll see in the attached diagram that wiring your alternator is very simple. To one field post supply twelve volts when the key is in the on position. Attach the other field post to the regulator post marked field or F. Beware regulators MUST BE WELL GROUNDED (A lot of charging problems can be traced back to bad grounds). Finally, supply the regulator with 12 volts on the post marke I, when the key is in the on position.

IT DOESN'T MATTER WHICH FIELD GOES WHERE! One field gets 12 volts, one goes to regulator, it doesn't mater which.

Hope this helps,

Regards,

Joe Dokes
 

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Yeah, I've got an old electronic regulator running on my truck alternator and it's been doing fine since the swap. Kind of nice to actually have a decent charge going at idle, lights don't dim at stoplights, lol. Holds a good 14.4 or so on the gauge at anything above probably 1000 rpm.
 
Thanks for your input and to Joe for a total clarification of charging system.

My wiring is exactly like on Joe´s picture, and output straight to battery with 4 Awg wire...

I did some searching from internet about the mopar voltage regulators and seems to be quite common problem with stock and "old school" powerline but not in 3G hemi swaps. Lot of opinions that quality of voltage regulators nowadays is not as good as used to be. Some say that it is good practice to collect those "good old ones" from junkyard :) Also engine compartment heat got some thoughts.

Maybe I order good lot of those on trunk and see what happens.
 
Just a quick clarification - do the factory 6.1 Alternators have an in-built regulator, or do the 300s and Chargers run an external reg as in Joe's diagram?
 
I am pretty sure that those cars are similar with 5.7 trucks, that originally the ECM controls charging voltage directly, so in the swap you need also that external regulator if a original engine management and wirings is not used.
 
All the hemi's are regulated by the computer, this is factory. The diagram above is for doing it hotrod style without any computer.
 
Ill be going "hot rod" style - only using the MSD6-Hemi for ignition.

Guess i'll look at retaining my existing charge system wiring.
 
I had a starter alternator guy make mine a 1 wire for ease of wiring--Steve
 
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