Sport Rider Photos
The combustion chambers of the F4RR cylinder head are machined instead of cast-in, allowing tighter control of tolerances and volume. Larger titanium valves (all four instead of only titanium intakes in the past; 31.8mm vs. 30mm intake, 26mm vs 25mm exhaust) are set at a true 2-degree radial angle to each other .
SPRP 2011 F4RR 008