98 A6?

thejimrose thejimrose at gmail.com
Tue Feb 12 16:23:06 PST 2008

weeeeelll.. not to go splitting hairs as all your advice is on the spot
Kent, BUT - yamaha switched back to 4 valve heads on the mi motogp bike and
then the r1 street bike. real world utility was hardly the priority. =)

materials and manufacturing improvements, variable-length intake runners [i
bet those are fun to fix when they break], fly by wire, etc etc all made the
3rd intake valve not necessary. they can make all the power they need with 4
valves, so no need to add cost / weight / complexity. which i guess is
race-world utility!

 Yamaha, who introduced 5 valves to the motorcycle world, went back
> to 4 valves for real world utility (manufacturing costs, mid-range power,
> valve
> adjustments, etc.)

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