Direkt zum Seiteninhalt



A well-running engine also includes optimized compression. Because you should neither risk an overheating or even a hole in the piston, let alone renounce performance. It is important that the compression ratio is optimal for tuned engines. Air-cooled engines do not tolerate such a high compression as water-cooled. In addition, the crushing dimension must not be undershot, since otherwise the piston strikes against the cylinder head.

worb5 vespa lambretta compression

Optimize geometric densification
The geometric compression is determined during the assembly of the cylinder head.
It is NOT the one found in the previous image with a compression compressor shown. We are talking exclusively about geometric compression and not about practical compression.

The compression is optimized by machining the cylinder head. The geometrical compression is determined by repeatedly multiplying the installed motor. At the same time, it is checked whether the crushing gap does not fall below a critical dimension of 0.8 mm for small motors and 1.2 mm for slightly larger ones.

worb5 vespa lambretta compression
worb5 vespa lambretta compression

The engine housing, the crankshaft, cylinder with piston and cylinder head is necessary to optimize this. The respective combustion chamber geometry is adapted accordingly on our lathe. After the turning process, it is re-assembled and compacted as a crimp edge.

worb5 vespa lambretta compression
The diagram below shows the thermodynamic efficiency. A compression increase to over 12 (geometric) does not lead to any significant increase in the output.

worb5 vespa lambretta compression

Basically, the following geometric densities are recommended:

Air - cooled standard cylinders: 9 to 10

Air - cooled tuning cylinders: 10 to 12

Water cooled cylinders: 12 to 14

Zurück zum Seiteninhalt | Zurück zum Hauptmenü