I had seen mention from time to time of dual alternator pulleys. I have a complete 77 slant motor that I rescued, that has this feature, roaming the local pull a part last week I found a 81 D-150 that had a dual alternator pulley,, only had one functional alternator belt though..

question,
1) anyone know why Chrysler had a dual pulley set up? I think these are used on the 65 watt alternator. Which is what the 83 D-150 has and has a single pulley.
2) are the dual and single pulleys really interchangeable? see photo, the root of the groves are not the same, the pulley on the far right is from the 83 D-150
http://www.flickr.com/photos/13718356@N ... 068840415/

just curious about why Chrysler did what they did.

thanks
DT

Dual belts were used on some V8s -- that is, two belts wrapping round the alternator pulley, water pump and crankshaft pulleys, etc. No such setup was used on a slant-6. The two 2-groove pulleys you show in the picture appear to be aftermarket items, but all of them look to be for the Chrysler alternator. Alternator output is rated in amps, not watts.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

right o on the watt's / amps,, was typing this in a hurry

and thanks for the info on the 2 groove application,, may explain why the groove spacing differs.

My 83 Dodge van was built with a 318 and the factory 120 amp alternator. The 120 amp alternator has dual pulleys due to the increased resistance created by the alternator when it really starts putting out the amps. I believe the dual pulley alternators were for high output alternators and/or A/C packages.

Dan- I don't recall, did the 120 amp slant six alternator setup I gave you have dual pulleys?

_________________
Casually looking for a Clifford hyperpak intake for cheap.

Any correctly-assembled dual-pulley alternator can be used on a single-belt application; the forwardmost belt sheave is not used. Don't recall if the \6 120A alternator has a dual-groove pulley, but there are no dual-belt drive setups on the slant-6.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

As I recall the dual belt setup was fairly common on V-8's with A/C. The alternator & A/C compressor had dual belts, while the water pump & power steering had a single belt.

_________________
63 Valiant Wagon
225 - 4 bbl