incl. VAT plus shipping costs
133ccm aluminium cylinder from Diffusione Ricambi (DR) with 6 transfer ports. Completely new developed cylinder which stands out from the well-known 133ccm cast iron cylinder. While the cast iron cylinder was still quite clearly oriented to the layout of an original cylinder, the new 133ccm aluminium has considerably larger cross-sections and porting area. Its performance is therefore more in the league of the well-known and popular Polini 133 cylinder.
With port timings of 116°/176° and a compression ratio of 11.4:1 (effective 6.1:1), the DR133 alloy matches perfectly the gap between cast iron Polini133 and aluminium Polini133 Evo.
Like the Polini Evo, the new DR133 uses aluminium which is very resistant to thermal stress and, thanks to its Nicasil coating, has a very low-wear sleeve plating. However, the DR combines this with port timings similar to those of the cast iron Polini.
Beautiful features such as additional cooling fins on the underside of the cylinder head, large transfer port cut-outs in the cylinder base and thin piston rings make the aluminium DR133 the ideal cylinder for a reliable and powerful touring engine. Thanks to the sporty but still pleasantly low port timings, it works both with a banana exhaust and 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.
Simpler and from our point of view more recommendable is the combination with a new racing crankshaft. A racing crankshaft not only has the appropriate inlet timings but is also equipped with a more stable connecting rod including bearing.
The DR133 can still be driven with the SHB19 without any problems. With a more breathable exhaust system, a 24mm carburettor with intake manifold and a rotary vane window surface treatment can generate even more power.
All parts relevant for the assembly are included in the scope of delivery:
Cylinder, head, piston, piston rings, piston pin, piston clips, head gasket, foot gasket, exhaust gasket, exhaust stud bolt (incl. nuts and lock washers)