Road Racing FIM Sidecar World Championship ... - Spelregels

2.3.49 Four Stroke Engines
01) Motorcycles engines of mass production only, with a Stocksport
homologation.
02) 4 cylinders maximum
03) The original crankcase and cylinders may be modified, but bore and stroke
shall remain as originally produced by the manufacturer.
04) Crankshaft and flywheel shall be original. Balancing and polishing is
allowed. Welding is not allowed. The minimum weight shall be 95% of the
original part.
05) Connecting rods may be altered or changed. The length shall remain as
original. The material shall be of similar alloy as homologated. The
minimum weight of a modified or replaced connecting rod shall be 95% of
the original part.
06) Pistons, piston rings and piston pins may be altered or replaced, but the
bore shall remain as homologated.
07) The original cylinder head may be modified, welding is allowed only in case
of repair (this means that it is not allowed to have each cylinder welded in
the same positions). The number of ports, valves, the diameter of the
valves shall remain as originally produced by the manufacturer.
08) Valves, valve springs and valve spring retainers may be altered or replaced,
but valve and valve spring material shall remain the same.
09) Carburettors may be altered or replaced. Fuel injection is free and can be
replaced by carburettors.
10) Camshaft may be altered or replaced.
11) The cam drive method shall remain as originally produced by the
manufacturer.
12) Cam sprockets can be modified or replaced.
13) The ignition/engine control system is free.
14) The gear ratios are free. The maximum number of gears shall remain as
originally produced by the manufacturer.
15) The clutch system type shall remain as originally produced by the
manufacturer. Clutch springs, plates and basket may be altered or
replaced. Mechanical back torque limiting capabilities are permitted (slipper
type clucthes). No electronic or electrical support is allowed.
16) The generator may be removed
17) Electric starter shall be in place and work. The engine shall start on the grid
with the electric starter for the warm up lap before the start of the race.
18) The use of exotic materials such as ceramics, metal matrix or aluminium
beryllium is not allowed.
19) Oil lubrication system is free.
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