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Spinning and milling
In the short term, all the turning work can be carried out. This is important when it comes to the adjustment of control times, compression and crushing edges, i. Cylinder heads and cylinders must be turned off. All milling operations can also be carried out.

In the machining of the cylinders, the better or more streamlined design of the transfer channels, the cross sections in general and the size of the channel cross sections at the cylinder foot outlet (cylinder base gasket). The outlet cross-section is also important.

worb5 vespa lambretta cylider spinning and milling

Boost Port
Individually, the Boost Port channel is called a support channel. This is the so-called 3rd overcurrent channel opposite the outlet. Here, too, the better, more flow-favorable design of the channel, of the cross-section in general, and the size of the channel cross-section at the cylinder-foot outlet (cylinder base gasket) are obtained.

Moreover, the design of the outlet is of great importance. A broadening (measured in the gauge of the tendon) up to 70% of the bore is quite common in the racing sport, whereby one should not go over 65% bsi 68% with everyday engines. A widening can lead to an increase in performance over the entire speed range. If the outlet is extended to the top, the nominal speed and the power increase - the force also decreases at low speeds = torque.

worb5 vespa lambretta cylider spinning and milling

worb5 vespa lambretta cylider spinning and milling

We can offer you a special treat for a 210 mm Malossi cylinder. Here, the original outlet nozzle is separated, welded aluminum, and the cylinder is machined so that a steel flange can be screwed on. This is the end of the exhaustion of the exhaust pipe. The next step is to weld the exhaust manifold directly to the steel flange. Absolute tightness is thus guaranteed. Problem with tearing due to vibrations is not, as long as it is an exhaust, which can be plugged after approx. 30 cm and thus a little floating with the exhaust main part is connected. But is actually the case with PM, JL, RZ and Scorpion. The outlet cross-section increases slightly.

Here the outlet channel is completely enlarged. The exhaust ports of the racing exhaust systems are significantly larger in diameter. Since the canal is also very long, some of the material has to be removed by milling.

worb5 vespa lambretta spinning and milling

Polini 130 ccm cast iron mono
Cylinder Complete machining 130 ccm Polini. The cylinder for a Vespa Smallframe is machined down to 3.2 mm and the top is 1.8 mm. The inflow windows are opened completely only by the "setting up" of the cylinder, resulting in more favorable control times. At the same time, the main flowers are milled larger and the outlet is machined. The boost channel is also expanded. This includes a 5 mm aluminum plate as a walking distance. The overflow must be adjusted generously to the engine block. To make it right, something should be welded and replanted.

We offer the 133 Polini for the Vespa Smallframe in the online shop in an already revised version.

Lambretta TS1:
An elaborate processing is the following: Really meaningful is only with a clamped TS1 225 cylinder anyway a new coating is needed. The cylinder is previously decontaminated. Then the main overflow lines are milled free from the cooling ribs in order to reach the ducts directly from the outside with the welding machine.

worb5 vespa lambretta spinning and milling Lambretta TS1

Now these channels are welded on the outside - later the cooling ribs are applied. The central boost channel is welded and two individual channels are milled in, which are larger in cross-section. The outlet and inlet are then machined according to customer requirements, the cylinder is planned downwards, the ducts are milled and the runner is coated again. This gives a "new" TS1 cylinder with larger overflow channels and a better boost port channel. (You can also use a Wiseco piston directly, or you can also extend the raceway upwards using a long-length stroke shaft, etc.).

worb5 vespa lambretta spinning and milling

Aluminum cylinder runway extend
How does it work ?? Why is this necessary? If a cylinder (eg Malossi 210 for Vespa or TS1 for Lambretta) is driven with a long-length stroke shaft (Vespa 62,5 mm and Lambretta from 62 mm), which is much longer in the stroke than the original stroke, if reasonable overcurrent times are obtained when using such long-stroke shafts.
This is limited by the fact that the cylinder can not be set as far down as desired without the upper piston ring jumping out of the track.

worb5 vespa lambretta spinning and milling

Remedy is only a complex processing. The cylinder is descaled and welded on top. Thereafter, the cylinder is pre-machined, i. afterwards to get a clean extended runway and increased plan area. Depending on that, some material on the cylinder will be turned off to get better timing. The dimensions should be well considered before. Then the cylinder is provided with a new coating - ready.

worb5 vespa lambretta spinning and milling
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