we have these two 78 amp alternators

1866268 ( BECK/ARNLEY )



and

1866002 ( BECK/ARNLEY )



both are basically same alts with the difference about the exterior look, being the last one with the newer look ( stator hidden by housing )

I don't really care much about the pulley since that can be changed ( my car is AC so uses dual )

BUT I'M WORRIED about the iddle charging. I know by A FACT the laters alt are able to feed better at iddle than earliers ( my 60 amps later alt is a proove ) because Winding is wider. But I'm trying to get one with same iddle charging power in the old look alt, with stator center visible. Also with old brushes plastic housings since they are easier to find locally

DOES SOMEBODY KNOWS if both of these alternators works the same. I know bouth shows same alt output, but dunno if at iddle the have same power.

If somebody has experience with these will be REALLY helpfull.

Or if you know who contact about this deal will be great. I already sent an email to Beck/Arnley ppl without succes yet.

I'm only able to find locally 60 amps alts and wish to get more juice ( no need for 100 amps, 78 is far enough ).



Thanks.

Natcho- I have the same type up top- mine is a 78 amp unit. at idle with no heavy load- the amp meter stays in the centre- but turn on the lights it dips at idle- as soon as I increase the idle- up goes the amps.

now the bottom one- stator covered??? never seen one- must be one from down your way.

It maybe the one I would try first to see what the dle would be. find the smallest pully for it- I think a 2 1/4 inch size is the smallest- that will speed up the rev's for it- but with this don't rev the motor for a long time up in the max RPM's as the alt will not like it!!!! so normal driving is ok.

no some guys tell me that a 80's alt is better at low idle- think that by them with all the extra electrical goodies and computer they made the stator a better unit for lower rev.s and more output. they don't look right in out beasts but a delco don't look right either as some have changed to it due to the lower power at idle!

the numbers don't mean anything to me- could be another Ven. numbering system.

John Mac

Hi John... I got an answer from Beck Arnley.... well not really from them... they submited to some kind of tech department... got this answer:

Hi Nacho:

Firstly, 186-6268 is not built to a 78a spec. The same unit - but 78 amps -is a 186-6001. Thus, the (2) 78a possibilities would be either 186-6001 ( single V groove pulley ), or 186-6002 ( double V groove pulley ).

Secondly, unlike most automotive alternators, the early generation Chyrsler alternators ( like these ) all used press-fit pulleys instead of the traditional pulley nut. Thus, swapping pulleys can be very difficult without a press.

We compared the output printouts of the 186-6269 (60a) and the 186-6002(78a) in stock at our BBB-California facility. We actually got 11 amps more low rpm output on the 78a unit (46 amps vs. 35 amps)!

If BECK ARNLEY has these in stock at their distribution centers, they can also look at the test result printouts that should be in each box & do thesame comparisons:

186-6268/6269 ( both 60a ) vs. 186-6001/6002 ( both 78a ) Looking at the “ALT rpm output at 2000 rpm” printout would give you a roughidea of their low rpm Idle capabilities, since 2100 ALT rpm is equivalent to approx. 700 ENGINE rpm. I would concentrate on the 186-6269 (60a) vs.186-6002 (78a) comparisons because these use the double V groove pulley youneed.

If you or anyone at BECK needs to contact me for clarification, feel freeto do so.

Best regards,

Steve Perovich
Technical Service Manager

BBB INDUSTRIES

so then, the specs published about the top one at Beck Arnley website is simply wrong about 186-6268... same of course than sellers who takes this info on his websites. Maybe the one you have is really 60 amps ? dunno.

and, then, just the lower one what is a little bit wider ( due wider stator, about 2 milimeters ) is able to feed more.

with "hidden stator" I want to mean the center is not visible like the one you have... this is the one I have on mine but 60 amps, is a lates 70s and 80s configuration. Note the one on the right side in direct comparision with the left one, same look than the one you have, but on pic is roundback. First squarebacks looks the same on side view.





The lower one on first reply is the same look than this on right. This uses also a diff brush isolator on one of them. Check attachment. Number one is the tipical earlier setup. Number 2 replaces this on laters squareback setup with "hidden stator"

This alt is a little bit wider than the one on the left what is the tipical alt found on our cars. For a better fitment, the rear spacer needs to be a little bit trimed, but also then belts a little bit longer than Mopar parts manual states due block clearences ( BTDT )

The one I have on my car, lates design ( 60 amps ) only registers some discharge with AC and pressing brakes at night ( lights on, halogen ). But wishing a little bit more in case of rain and working wipers at least in slow speed.

regular stock alts ( earliers kind no matter if round or aquarebacks ) really don't provide more than 55 amps.