The CBR1000RR Fireblade SP2 is a road legal homologation special using the Fireblade SP as a base, ready for race use.
Revised cylinder head: valves, combustion chambers and pistons
Racing kit to be available
Visually the carbon pattern insets and gold striping interwoven into the Tricolour paint mark the Fireblade SP2’s difference over the ‘stock’ machine and gold Marchesini wheels (reducing front/rear wheel inertia by 18/9%) are another clue. But the real differences – and what gives the Fireblade SP2 ultimate racing potential – lie inside the engine and, in turn, the parts that can be added from the two race kits that will be available.
While the 76mm bore is identical to the SP, the Fireblade SP2 cylinder head runs 1mm larger 31.5mm diameter intake valves and 1.5mm larger 25.5mm diameter exhaust valves, with 10°/12° included valve intake/exhaust included valve angles (from 11°/11°). The valve pitches are identical, maintaining cylinder head width.
It runs the same 13.0:1 compression ratio but uses valve shapes and combustion chambers optimised for efficiency. Elongated spark plugs and a water jacket tightly wrapped around the combustion chambers improve cooling; this technology is derived directly from Honda’s RC213V MotoGP machine.
The pistons use an exclusive crown design with heat treatment that strengthens the area around the piston boss, which itself employs a 2.5mm shorter (and 8g lighter per cylinder) piston pin. Ready to house high-lift camshafts the outer diameter of the valve lifter has grown 2mm to 28mm, while total height and thickness have been reduced saving weight.
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