Changing cam lift on a RC51 should only be done on a dedicated race motor and with a very clear understanding that if you use cast cams you will end up snapping a cam at some point. The same results are not uncommon if you raise the hard rev limit on the bike.
The best bang for your performance dollars is high compression pistons (if you are using JE keep in mind that they were originally HRC copies and require HRC heads to get to the rated compression figures), stage one cams, airbox, head/port work and finally doing everything you possible can to put the bike (and rider) on a diet. If you are going through this much, lightening the crank and rods is a must as well.
FWIW, adjustable cam sprockets are not required on the RC51 as the timing can be altered using a PowerCommander PCIIIr.
|