Jim,

I am shame-faced, my idle (no pun intended) speculation and cursory
vanagon archive search led me to public display my ignorance :)

Thanks for the info.

ab

On 3-Jul-05, at 8:57 PM, Jim Arnott wrote:

Alistair... You of all people should KNOW!  You're the expert.

However, list member Shawn Wright posted the following on the
Diesel-Vanagon list a while back:

I finally got around to measuring the pulleys I have on hand, and found
the
results a little puzzling, as they are the opposite of what I expected,
and
what I recall reading here a while back (I can't find the post right
now). It
appears my A2 Jetta 1.6TD pulley combination results in a faster turning
water pump than the stock DV setup. Here are the numbers, measured on
the outside rim of each pulley. Of course the actually belt diameter
will be
less, probably 15mm or so.

TD Crank 1 (inner, wp & alt): 149mm
TD Crank 2 (outer, ps): 122mm
TD WP: 115mm

Ratio, Crank:WP = 1:1.30

DV Crank 1&2: 135mm
DV WP 1 (inner, to alt): 135mm
DV WP 2 (outer, from crank): 115mm

Ratio, Crank:WP = 1:1.17
Difference from DV to TD = 10.4% increase in WP speed.