Quoting Al Gietzen <ALVentures@cox.net>:

> Subject: [FlyRotary] Re: E-shaft pulley diameters
>
>  
>
> Al,
> That's probably good advice.  Do you know what other 20B guys are doing?  I
> only know of Tom Parkes that has actually flown.  I think I have his e-mail
> address and can ask him about his pulley arrangement.  
>
> Thanks,
> Mark
>
>
>
>
> I don't know what others are doing.  I got a 3" double sheave pulley for the
> alternator from Racing Beat.  Having decided to dis the smog pump (vacuum
> pump) in favor of all electric, It made sense to go to double belt on the
> alternator.  Water pump is also 3" and e-shaft is 4-1/2"
>
>  
>
> Al
>
>
Al,
Measured my e-shaft pulley at 5-1/4", and the wp pulley at 3-7/8".  The
alternator pulleys are 2-1/4 and 2".

I tried mixing and matching some single and double-V pulleys I had from a junker
13B with some interesting discoveries.  First, the water pump pulley wouldn't
fit all the way down onto the 20b pump.  I could prbably make it fit by
grinding down some of the webs on the wp housing, but I don't want to do that
for obvious reasons.  One solution would be to change to the 13B pump and
housing, but that would require a number of other changes in the cooling
system, so I don't want to do that either.  

Due to mis-alignment of the pulleys, in order to use the double-v crank pulley,
it would require repositioning of both alternators.  That would be very
difficult to do.  So I think the best approach is to locate some oversized
alternator pulleys for the dual ND alternators (multi-v style).  And if I can't
locate a source (at a reasonable price), then I'll make them myself.  And for
now, I'll leave the wp pulley and crank pulley as is.  

Mark S.