Twin-cylinder four-stroke air-cooled rebirth of a Ducati 500SL

Engine

Twin-cylinder, 90° L-type configuration, 4-stroke, air-cooled, mounted on closed double cradle frame.

Bore 74mm
Stroke 58mm
Capacity 498.9cc
Compression ratio 9.5:1
Max power 45HP @ 9050 rpm
Max torque 40.2 Nm @ 6300 rpm
Max engine speed 9500 rpm

Valve Timing

Induction before TDC 50°
after BDC 80°
Exhaust before BDC 75°
after TDC 45°

Operation and clearance of tappets, cold motor condition:

Intake and exhaust opening rocker arm 0.10mm (0.0039″)
closing rocker arm 0.00%0.02mm (0.00%0.0008″)