Racing cylinder 125-150 ccm, 3 ÜS
for Vespa 125 GTR 2°-TS/150 Sprint 2°-Super 2°/P125-150X/PE/Lusso/MY/P150S/Cosa/LML Star by SIP Scootershop
Almost all 125/150 Vespas since the mid-60s are equipped with this engine. These are the models Vespa 125 GTR VNL2T 138957 -> /TS/150 Sprint VLB1T 105200 -> /Veloce/Super VBC1T328129 -> /Cosa 125-150/P125-150X/PX125-150E/Lusso/MY/P150S and LML 125-150 Star Deluxe/DLX/Star/Stella Belladonna. There is a wide range of largeframe cylinders here.
All these cylinders can also be fitted to Vespa P80X/PX80E/Lusso/PX100E models if a PX125 crankshaft with 57 mm stroke is also fitted. If you do not want to use the cylinders that are specially machined for the PX80, the narrower cylinder base of the PX80 must also be spindled for the 125 cylinders.
The following cylinders can also be run on the 2-overflow engines. For this, however, the 3rd overflow in the cylinder must be closed or the boost port must be milled into the engine housing. Here too, we already have modified versions in our range.
Popular tourers are D.R., PINASCO and the POLINI. These cylinders are very grateful companions in combination with a 24 carburettor and SIP Road exhaust. Our long distance record with a POLINI 177 stands at 4500 km, Landsberg - Thessaloniki, Greece: two weeks, without engine breakdown. MALOSSI and QUATTRINI stand for sports and racing use respectively. Both cylinders can also be used for touring with the right set-up. However, they have enormous potential and are therefore more suitable for sport or racing use. The QUATTRINI on the SIP Custom Basterd currently has just under 28 hp and acceleration across all rev ranges that makes many 210s dizzy.
Customers ask - SIP answers
"Do I need to run in my cylinder?"
Yes. The piston is travelling at an impressive speed in the cylinder bore. At 20 m/sec, that's 72 km/h after all. The piston, rings and cylinder must fit together perfectly. These tolerances are infinitesimally small, in the micrometre range. During the running-in period, the moving parts rub against each other to achieve a perfectly coordinated shape. The aim of the running-in process is therefore not, as is often claimed, to produce the smoothest possible surfaces, but to produce components that fit together as well as possible. By the way, the recommended running-in time is not 1500 km or similar fantasy figures, but one hour! Warm up the engine carefully, avoid maximum load, increase power output slowly.
Caution: The engine must be run in again if any of the components (pistons, piston rings (especially!) or cylinders) have been replaced.
