What SU stands for

[Mike Morrin]

At 08:40 8/07/98 +0100, Andrew W. Macfadyen wrote:
>Lucas real weakness was alternator; the ACR series tended to have a 40k
mile life
>without a rebuild partly the fault of the car manufacturers who under
sized the
>unit to cut costs and tried to compensate by using a smaller pullley to
spin the
>alternator faster. . Main land european cars tended to use much  higher rated
>units. Most UK cars used a 35ACR   a 35 amp  rated alternator where a
German car
>of the same size would use a 45 amp unit.  

Good story, but not true.  The 17, 20, 25 etc in Lucas model numbers does
not refer to the current rating.  From a 1975 Lucas catalogue I get:
15ACR = 28 Amp
16ACR = 34 Amp
17ACR = 36 Amp
18ACR = 43 Amp
20ACR = 63 Amp or 66 Amp
23ACR = 55 Amp
25ACR = 65 Amp

>Worst was the UK version of the Chevette
>only  had a 25 amp alternator -- it would fail to   meet the demand by
about 5 amps
>with all the lights and heated rear window on.

The Chevette had a 17ACR.

The problems with the Lucase alternators were the brushgear which really
did wear out at about 40k miles on some models, perhaps the brush springs
were too strong and the rectifier assemblies on the smaller units which
would fail due to vibration and the subsequent stress on the diode wires.
regards,

Mike Morrin