Description
Polini is one of the leading manufacturers of 50cc tuning parts, and they are also one of the big names when it comes to tuning and custom parts for Vespa, Classic and Modern. They carry cylinders, exhaust systems, carburetors, crankshafts and many accessories to improve the performance of your Vespa.
This Polini Camshaft Vespa GTS/GTS Super/GTV 300cc 4-stroke LC is a high-end tuning part designed for racing. Inlet timing was increased from 7.3mm (standard) to 8.4mm, exhaust valve timing from 6.9 to 8.1mm. This results in higher torque and improved overall performance.
The camshaft was developed for Polini's high-end cylinder kit P140.0217, using the original piston may require some modifications.
Camshaft and valve timing
The camshaft and valve timing are important components of 4-stroke engines. The camshafts allow the valves to open (i.e., to draw in the mixture and expel the gases) and are driven by the timing chain, which is in turn connected to the crankshaft.
Incorrect timing adjustment interferes with valve opening and can severely affect engine performance and reliability. Therefore, we recommend to intervene only with appropriate technical know-how.
Maintenance and tuning
Maintenance and care of the elements located in the cylinder head, including valve timing, is very important. Even though the timing chain generally has a fairly long life, it is still necessary to regularly check chain wear and wear of all related elements.
Camshafts must always be in perfect condition. You can also use tuning camshafts; the shape of the cams is revised to increase the valve opening times and thus provide more power.
Tuning Level: Sport
We categorize our products into different performance levels Original, Sport, Racing and High End , so that our customers can choose the right parts for their setup. It is really important to combine parts that belong to the same tuning level, this is especially true for cylinders, crankshafts and exhausts.
The products listed under Sport yield better performance than Original parts. They may have technical differences, such as the use of higher quality materials, a larger displacement or a performance-enhancing design. They are suitable for everyday use and have a long service life.
Aluminium cylinders
Aluminium cylinders are more powerful than cast iron cylinders, but require more regular maintenance and must be combined with different components such as a reinforced crankshaft and a larger carburetor.
How to run in an aluminium cylinder?
Aluminium cylinders should be run in for about 200 kilometers , and you should use a fully synthetic engine oil.
Note: To ensure optimum performance and reliability, it is advisable to measure the squish clearance. Just have a look at our tutorial How to adjust squish clearance.