Cylinder Polini P.R.E 4 100cc 52mm Minarelli / Piaggio scooter LC

Cylinder Polini P.R.E 4 100cc 52mm for Minarelli / Piaggio scooter LC.

If you are preparing your bike for the track, with Polini PRE 4 or Malossi RC or C-One crankcases, the Cylinder Polini P.R.E 4 100cc FL system is the next step when you are looking for more power and torque than with the 70cc.

The Polini engineers have optimized the Cylinder with a 52mm bore and 47mm stroke, along with a 16:1 compression ratio, a Squish of 0.65mm and much larger transfer ports. This allows for a much greater filling and a fuller power delivery throughout the entire rev range.

This translates into a much higher performance, with more torque from the bottom and a more progressive yet forceful curve. You will notice the difference when exiting corners and in the reaction capability on long straights, without losing aggressiveness.

Cooling has also been improved, working at around 50-55°, definitely a point to consider on the track. The fuel must be at least 100 octane and a mixture of 4% for karting and 5% for long circuits.

Without a doubt, it is a component made from pure engineering, but do not forget that if you want to squeeze the Cylinder to the maximum you must install other matching components.

Advice

• Polini Oversize transmission kit
• Polini PRE 4 100cc exhaust
• Carburettor Voca PWK 28 to 32
• reed valve Vforce 4
• Polini P.R.E 4 crankshaft Connecting rod 100mm

Technical specifications

• Bore (mm): 52
• Stroke (mm): 47
• Displacement (cm³): 99.7
• Piston pin (mm): 14
• Squish (mm): 0.65
• Length of Connecting rod (mm): 100
• Ring end gap (mm): 0.45-0.50
• Piston - Cylinder clearance (mm): 0.08-0.10
• Compression ratio: 16
• Tightening torque - Cylinder M7 (Nm): 14
• Tightening torque - cylinder head M7 (Nm): 14
• Tightening torque - cylinder head M5 (Nm): 8
• Mixture percentage in karting: 4%
• Mixture percentage in long circuits: 5%
• Optimal operating temperature (°C): 50-55
• Gasoline: 100 octane min