| The New Valvola RS has many
changes. Compared to the old Valvola, it retains the same crankshaft,
wrist pin, head insert, bearings ( 6000 and 607) and conrod but everything else has
changed. Notably the transfer timing is lowered from 131 on the Valvola to
128 degrees on the RS Valvola, the
crankcase is stronger, the
exhaust now has a main port and 2 large sub ports, the piston is
stronger, the drum is lighter but unbalanced and has a slightly smaller bore, there
is an aluminium fixed ramp/stuffer in the end of the drum, the induction
tract length is much shorter and the carb is now a flange fitting and is retained by 2
x M2.5 screws. The exhaust stub OD is larger by ca 0.5mm, ID larger by
0.5mm. |
Exhaust
182
Transfers 128
Boost 131
Induction opens 151 BTDC closes 56 ATDC (29/56)
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Valvola RS piston on the right showing
the smaller bypass port to give more piston strength. |
Carb mounting on the drum, very small
induction port at the carb side. |
Shows the aluminium ramp that fits inside the drum. |
 |
Screw fixing for induction ramp. |
RS liner on the right showing triple exhaust ports |
Nice venturi/bellmouth on the new carb. |
RS liner on the right showing triple exhaust ports |
