Alternator differences
#2447810
02/07/18 01:06 AM
02/07/18 01:06 AM
|
Joined: Nov 2004
Posts: 507
340clone
OP
mopar
|
OP
mopar
Joined: Nov 2004
Posts: 507
|
I am looking to replace the alternator in my '74 Charger with a 440 to freshen up the engine compartment, and would like to keep it looking original. Car has factory A/C, tach and radio, and being a '74 it has electronic ignition. No other power options.
What would be the minimum amps advisable for these options, and also, how many amps would be recommended? Is the factory unit a 65 amp?
What year did the square-back come out? Was it '72?
If anyone could shed some light on which alternator should be used, it would be much appreciated!
Last edited by 340clone; 02/07/18 01:07 AM.
|
|
|
Re: Alternator differences
[Re: 340clone]
#2447870
02/07/18 03:11 AM
02/07/18 03:11 AM
|
Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
I'd get any mid 70's (squareback) alt at your parts house whatever is the highest amperage available right before the 78 amper came out for the 85 M bodies, that one has a thin stator & reportedly needs the common cheap chebby chrome swing arm (I ain't done it but I would work around needing that part) but you wanted OE for your year range. more important would be to clean ALL terminals/cables/connections from head to toe expecially in the alt sense circuit & clean the bulkhead & the batt to block/eng to firewall ground paths. grab your meter/check your voltage drops/charging rate. EDIT #1 caveat, don't use the alt to charge up a depleted batt & #2 if the system ever full fields for whatever reason (goes to max voltage) unplug the reg & drive home on just the battery & deal with it later & slo charge the batt back up on a charger.
Last edited by RapidRobert; 02/07/18 06:21 PM.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: Alternator differences
[Re: 340clone]
#2447882
02/07/18 04:38 AM
02/07/18 04:38 AM
|
Joined: Aug 2003
Posts: 43,195 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,195
Bend,OR USA
|
I'm not sure if Mopar offered a hi output alternator for your car in 1974, having air conditioning stock it should have had a large output 65 amp alternator from the factory When it comes to the running load ability of any alternator it will only put out the amps needed to keep the battery a certain voltage hence seeing battery read 13.+ volts at the battery when running with no load other than the ignition and the alternator charging the battery back up from starting the motor It shouldn't put out more than 14.5 volts when running after starting, I think Your stock alternator should be fine as long as it puts out the amps it is design to put out IHTHs
Last edited by Cab_Burge; 02/07/18 04:39 AM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Alternator differences
[Re: 340clone]
#2447893
02/07/18 05:37 AM
02/07/18 05:37 AM
|
Joined: Feb 2003
Posts: 10,214 Someplace you aren't
SomeCarGuy
I Live Here
|
I Live Here
Joined: Feb 2003
Posts: 10,214
Someplace you aren't
|
Power master has a stock looking one that will light up a City block with its 95 amps. I don’t think you need that one or the wiring upgrade you’d need to do, but just throwing that out there.
I want my fair share
|
|
|
Re: Alternator differences
[Re: crackedback]
#2448125
02/07/18 06:24 PM
02/07/18 06:24 PM
|
Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
^^^ yes there are 2 sizes of alt pulleys & you want the smaller one along with a std 7&1/4" crank pulley & a ~6" or so pump pulley for good coolant/fan (air) speed.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: Alternator differences
[Re: a12rag]
#2448137
02/07/18 06:43 PM
02/07/18 06:43 PM
|
Joined: Jan 2003
Posts: 25,817 Rio Linda, CA
John_Kunkel
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 25,817
Rio Linda, CA
|
The Alternator will only put out what your system draw is . . . Another factor, often overlooked, is the rpm that the alternator produces its maximum output. Factory alternators are notorious for low output at lower rpm. With the introduction of lower numeric axle ratios and more accessories, the alternator wouldn't keep up with the load at lower speeds. (the dim lights syndrome)
The INTERNET, the MISinformation superhighway
|
|
|
Re: Alternator differences
[Re: 340clone]
#2448315
02/08/18 01:58 AM
02/08/18 01:58 AM
|
Joined: Feb 2003
Posts: 10,214 Someplace you aren't
SomeCarGuy
I Live Here
|
I Live Here
Joined: Feb 2003
Posts: 10,214
Someplace you aren't
|
Problem with just tossing a big alt on without adding a shunt is if you ever do end up for whatever reason drawing more amps than your harness can handle you’ll be in trouble. Like if you don’t remember to do so five years later and start adding stuff. Or the next owner, and so on.
I want my fair share
|
|
|
Re: Alternator differences
[Re: ahy]
#2449352
02/10/18 12:46 AM
02/10/18 12:46 AM
|
Joined: Aug 2007
Posts: 6,095 Valencia, España
NachoRT74
master
|
master
Joined: Aug 2007
Posts: 6,095
Valencia, España
|
A later squareback at 78 amps would have more output but do you need it? A Powermaster squareback would have even more amps and good chance it is reliable.
not because the 78 amps as max output, but the ~45 amps iddling these put out. but more, the better
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
|
|
|
|
|