Cylinder -DR 133 cc 6 Transfer Ports, alloy- Vespa PV125 ,ET3 125, PK80-125

133ccm aluminium cylinder from Diffusione Ricambi (DR) with 6 overflow channels Completely new developed cylinder which clearly stands out from the well-known 133cc grey cast iron cylinder. While the grey cast iron cylinder was still clearly oriented on the layout of an original cylinder, the new 133cc aluminium cylinder has considerably larger cross-sections and purging areas. Its performance is therefore in the league of the well-known and popular Polini 133 cylinder.

• displacement: 130ccm
• stroke: 51mm (Series 90Racer, SS90, PV125, ET3, PK80-125)
• bore: Ø57mm
• control angle overcurrent/exhaust: 116°/176°
• compression: 11,4:1 (eff.6,1:1)
• Time of ignition: 19° F.O.T.
• pinch point: 1.2-1.4mm
• spark plug: B8HS/W3AC

With control angles of 116°/176° O.D./A.S. and a compression ratio of 11.4:1 (effective 6.1:1) the DR133 Alu punches exactly into the gap between grey cast iron Polini133 and the Polini133 Evo made of aluminium.
The new DR133 uses, like the Polini Evo, the thermally very resistant aluminium which, thanks to the Nicasil coating, has a very low wear track. But the DR combines this with similar touring friendly steering angles as the Polini. Beautiful features like additional cooling fins on the cylinder head underside, large overflow cutouts in the cylinder base and thin piston rings make the Alu DR133 the ideal cylinder for a reliable and powerful touring engine. Thanks to the sporty but still pleasantly low steering angle it works with a banana exhaust as well as with tame resonance systems such as the PM40. Further tuning is also no problem thanks to large cross-sections and thin piston rings.

DR recommends extending the intake control angle by modifying the standard crankshaft.
Easier and in our opinion more recommendable is the combination with a new racing crankshaft. This crankshaft does not only have the right timing angles but is also already equipped with a more stable connecting rod and bearing.

The DR133 can be used with the SHB19 without any problems. With more breathable exhaust systems, a 24mm carburettor with intake manifold and a machining of the rotary vane inlet window area can generate even more power.

The scope of delivery includes all parts relevant for assembly:
cylinder, head, piston, piston rings, piston pins, piston clips, head gasket, foot gasket, exhaust gasket, exhaust stud bolt (incl. nuts and lock washers)