Long Stroke Crankshaft from MAZZUCCHELLI for Vespa Largeframe Engines. More displacement, more torque and the right basis for touring or sports setups.
A larger stroke enables more displacement - and more displacement means more power. Most 200cc Engines, whether race or road tuned, are therefore based on Long Stroke Crankshafts. The extra stroke is compensated for by Spacers, i.e. thicker gaskets, on the Cylinder Head and/or Gasket Cylinder Base. This allows the timing to be specifically influenced and adapted to the desired engine concept.
- 60 mm stroke for more displacement and torque
- Extended intake time for powerful setups
- Silver bearing on the lower connecting rod bearing
- Also available as a reinforced K2D version
With Long Stroke Crankshafts, the Crankpin sits further away from the crankshaft axis of rotation. For 60 mm shafts, this is 1.5 mm. The Piston moves beyond top and bottom dead center by this 1.5 mm. Spacers must be fitted to the head and/or base or suitable SIP/MMW cylinder heads to prevent it from hitting the Cylinder Head. The timing will change in any case.
The MALOSSI 210 cc Cylinder has different characteristics:
- 1.5 mm compensation at the base ensures a wide rev range and high horsepower figures, but with less torque and a later onset of power boost.
- 1.5 mm compensation at the head provides brute torque at lower engine speeds, but slightly less peak power. This variant is a popular touring combination, also in conjunction with long gear ratios.
Like the Racing Crankshaft, the MAZZUCCHELLI Long Stroke Crankshaft has a significantly longer intake time. Depending on the version, the Conrod is designed as a polished knife-edge connecting rod, the lower connecting rod bearing as a silver bearing. A reinforced K2D version is also available. Due to the higher strength of the K2D alloy, a higher pressing dimension can be achieved on the Crankpin, which increases torsional rigidity even without welding.
Technical details
- Stroke: 60 mm
- Conrod: 105 mm for 125/150 cc, 110 mm for 200 cc
- Shaft seal seat: 24 mm
- Bearing seat: 25 mm
- Lima cheek: Ø 95 mm
- Rotary valve cheek: Ø 97.9 mm
- Partially balanced to 12 Clock position
- Lower connecting rod bearing: Silver bearing
- Cone: blunt, thick cone
- Thread: M12
- Connecting rod bearing included
- Also available as a reinforced K2D version
Conclusion: The MAZZUCCHELLI Long Stroke Crankshaft is the perfect basis for high-torque touring engines or high-revving sports setups.
SIP TIP:
- SIP/MMW long-stroke head, MALOSSI 210 cc and SIP Road Exhaust are suitable for touring setups.
- For sports setups, a 1.5 mm foot gasket, SIP PERFORMANCE, RZ or DSE Exhaust, MALOSSI or POLINI Cylinder and 28-30 mm Carburettor form a strong basic framework.
- feel free to test foot and head gaskets ofdifferentthicknesses.
The timings stated above were determined viewing in the direction of the clutch side. That means: "138°/6° after TDC: Inlet timing begins 6° after TDC and stays open for 138°.
Please note that the angular degrees given here are approximate values, as the crankshafts are reworked by hand.