Jim,
   Looking into warerpump impeller design is way past my desire or ability........I am sure
that with enough  time and money a more efficient pump can be had......That being said
I want to get into the air in this lifetime and chose to use the stock pump which has been
proven by Tracy and many others........It has also been documented by several that the
stock pump is on the edge of cavitation between 6500-7000 engine rpm........For that
reason I think it would be prudent to underdrive the pump for those of us using the
RD1C 2.85 redrive........Tracy, Ed and others are already closing in on 7000 rpm in cruise
if they choose........Tracy runs well over 7000 rpm when racing........The reason that the
warerpump pulley in question is 5 inches in diameter is that with the reduced diameter
"Racing Beat" eccentric shaft pulley that most of us use it is impossible use a larger
pulley on the waterpump....... IMHO
--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2




    -------------- Original message from Jim Sower
    <canarder@frontiernet.net>: --------------


    > Kelly and all,
    > I might have missed this too, but do you know if anyone (like the
    > racers) has looked into impeller design of EDWP and come up with
    > something that operates better in our envelope? The turbine looking
    > design of the EWP suggests that a unit like that /hugely/
    underdriven
    > would be much more optimal for our purposes. But unless it was
    really
    > popular, would probably be hugely expensive. As for your
    pulleys, 5"
    > doesn't sound like a lot to me. A pump that works in stop-and-go
    > traffic with the AC on and engine at idle (< 1000 rpm) seems
    like it
    > would work OK at 7500 rpm with about a 8" pulley, unless you're
    planning
    > on going with a smaller drive pulley to underdrive the
    alternator too.
    >
    > I'm currently looking at a 13B with RD1C operating at 7500 rpm
    cruise
    > and capable of 8000 or so if I get in that big a rush. Stock
    pulleys
    > wouldn't do at all for that application I'd think. I need about
    210 hp
    > for what I aim to do, and extrapolating 160 hp linearly from
    6000 rpm
    > barely gets me there. Anyway, I need to start keeping better
    track of
    > happenings on this list.
    >
    > Sorry to be doing all this catching up "on company time" ... Jim S.
    >
    >