Crankshaft by Mazzucchelli with small taper for the Vespa PK 50 S.
This racing crankshaft features an extended intake timing and a polished connecting rod.
- Stroke: 43mm
- Needle bearing on top: yes
- Racing crankshaft: extended timing
- Small taper: 19/20mm
The crankshaft also fits Vespa V50 and, unlike the latter, has a needle bearing in the upper connecting rod eye, providing increased durability for tuning.
Standard Crankshaft vs Racing Crankshaft
Timing
Unlike a standard crankshaft, a racing crankshaft is characterized by a modified crankshaft cheek - the so-called "disc valve". The disc valve's cutout is larger, allowing a longer period of mixture flow through the disc valve intake during one crankshaft rotation. A racing crankshaft ensures efficient fuel supply even at high RPMs, providing a linear "power delivery" without drop-offs.
Especially engines with larger displacement and sporty channel design require optimized mixture supply, particularly in the highest gear under full load at certain RPMs.
Connecting Rod
This racing crankshaft features a polished connecting rod. Such a rod reduces flow resistance and mixture turbulence.
Mazzucchelli code: AMT158
