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Kevin,
Do not know what you mean by "motorcycle stuff"......."Star Racing" website
only has info about their "Mazda" powered race cars including photos of
complete engines showing the oversize waterpump pulley in question installed .
Would be your call whether toothed belt pulleys are better........I am sure they
would be more expensive.......The "Star" WP pulley is 5 inches in diameter and
sells for $74.32 + UPS shipping.......The "Racing Beat" eccentric shaft pulley
that must be used with it approx. 3.875 inches in diameter and sells for $65.00
+ shipping from "Mazdatrix".......This pulley combination provides a underdrive
ratio of .775 to 1 (22.5 % reduction).........7000 engine rpm = 5425 waterpump rpm.
The stock "Mazda" pulleys provide a 16 % overdriven ratio of 1.16 to 1........
7000 eng. rpm = 8130 wp. rpm.......This is well past the demonstrated cavitation
point of 6500 to 7000 rpm........The "Racing Beat" pulley used with the stock
waterpump pulley (about 1 to 1 ratio) works well for the guys using the 2.17
redrive as they usually operate between 5000 and 6000 rpm which is below the
cavitation rpm.......The guys using the 2.85 redrive are seeing cruise rpm of
6500 and up.......Ed Anderson has seen 6800 rpm at last report and Tracy has
seen well over 7000 rpm racing.......So IMHO those with the 2.85 redrive need
to slow down the waterpump both for efficiency and reliability reasons !!
Photo attached are "Star Engines" with both these pulleys installed.......I did
not ask "Star" if they sold the eccentric shaft pulley as I already had one......They
probably sell both.......I call it a "Racing Beat" pulley because they developed
it and I believe supply then to other dealers such as " Mazdatrix" and Probably
"Star" also........You might check to see if "Star's" price is better........FWIW
Kelly Troyer
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Kelly - I couldn't find the pulley, just motorcycle stuff. what will a set cost and how much reduction will it produce? would a set of toothed pulleys cost more, or be better?
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-------------- Original message from keltro@att.net (Kelly Troyer): --------------
Ed and All,
Ok guys here is the straight skinny !! Received the "Star Racing" pulley
today (ordered Monday the 21st).......It is a beautiful piece of machine work
(obviously CNC), hard anodized in black and a perfect match for the eccentric
shaft pulley from "Racing Beat" that most of us use.......Perfect fit on the 86 to
88 13b pump with the 17 mm pilot.......will be a simple job to bore to 19 mm for
those using the 89 to 91 or Cosmo 13b and 20B pump.......Looks just like the
attached PDF........Great service from the "Star" parts dept.........They are in
business to sell parts mainly to guys that buy their race cars........They did
not ask what type of vehicle I had but it might be wise to not mention that
ours are aircraft........Off road would be a prudent answer probably so as not
to dry up a parts source.......Price was $74.32 plus UPS shipping........Contact
"Star" at the following E-mail and phone #........FWIW
(PS- I asked about a quanity discount.....They said their markup was not
enough to allow it)
Kelly Troyer
From: "Star Race Cars Parts Department" < fmparts@starmazda.com> To: "Kelly Troyer" < keltro@att.net> Subject: Re: Waterpump pulley Date: Fri, 18 Mar 2005 21:03:33 +0000
Here is a couple of pictures with some approximate dimensions of our water pump pulley.
Our part # is 050-521and costs 74.32.Please email back if your interested(include a fax#
if you have one)
thanks
Jason Lindsey
Star Race CarsParts Dept.
(818) 686-3356
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