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Vespa T5 199 cc Racing Cylinder Kit
The Vespa T5 engine is considered to be the most modern engine that Piaggio has designed for the classic Vespa models with manual transmission. Unfortunately, the T5 Engine is relatively rare compared to other Vespa engines. As a result, the selection of tuning parts is also less varied. However, the T5 Engine with its large transfer ports and wide Crankshaft offers the best opportunities for performance increases. " The aim when developing the SIP PERFORMANCE 199 cc Cylinder was to offer a plug and play setup that enables a perfectly working, powerful Engine- ideal in its characteristics for everyday use and touring," says SIP Scootershop CEO Ralf Jodl. " In addition, the Cylinder should offer many reserves and possibilities for tuners and developers to fully exploit the potential of a T5 Engine." The Vespa T5 has a standard displacement of 125 cc. The installation space for the Crankshaft and Cylinder offer the potential to accommodate a 200 cc " Plug and Play " set-up. This SIP PERFORMANCE Cylinder is the first T5 tuning cylinder to utilize this displacement potential according to Ralf. This is achieved by a bore of 65 mm and a stroke of 60 mm, meaning that the conversion to the Cylinder also requires the use of a Crankshaft with a stroke of 60 mm and a connecting rod length of 115 mm. The Cylinder uses a 5-channel transfer port system, designed so that the Cylinder can be installed plug and play on the original transfer ports of the T5 Engines. However, the channels in the Cylinder have been shaped in such a way that they offer potential for expansion at the transition to the Crankcase. The bridge between the transfer ducts in the original T5 Crankcase can also be optionally removed to further optimise the transition. The exhaust duct is designed in three parts: a large central outlet and a side outlet on each side. The secondary outlets run inside the cylinder studs. " As a result of numerous test bench runs, we have developed an optimized geometry that ensures sufficient cross-sectional area for the secondary
outlets to work effectively. " The T5 ' s exhaust flange is designed so that the Exhaust is pushed into the flange piece on the Cylinder and fitted. As the original manifold diameter is designed for 125 cc, we have decided to design the flange piece on the Cylinder so that it can be screwed on. " The Cylinder is supplied with a Flange that is compatible with T5 exhaust systems. It is fastened with two screws, sealed with an O-ring and also offers the option of attaching springs. However, it is also possible to replace the Flange with a version with a larger diameter. Threads with a larger radius have been used for this purpose. This allows exhaust systems with a larger Exhaust Manifold to be adapted." The 65 mm Piston has two 1 mm thick steel piston rings and a biconical Gudgeon Pin. As is usual with T5 engines, the head has a centered Spark Plug. The squeeze area is 47 % of the piston area. The combustion chamber engages in the Cylinder and thus ensures perfect centering. The option of using the original Centring Bushes still exists but is not required in the Plug and Play setup. The head and Cylinder are shaped so that the original rubbers can be fitted for Vibration Damper. The Cylinder can be run with the original T5 Cooling Hood. However, the 10 mm longer Conrod requires the Cylinder Cowling to be spaced out. The easiest way to adapt this is to use a Flywheel Cover- Cylinder Cowling Cover.
SIP SCOOTERSHOP GMBH Landsberg, GERMANY Tel: + 49( 0) 8191 9699969 martin @ sip-scootershop. de www. sip-scoot
38 IDN- JANUARY / FEBRUARY 2026 www. idnmag. com