Cylinder -MALOSSI SPORT aluminum 177 ccm 3 port, 57mm stroke, 1-piece exhaust- Vespa PX125, PX150, Cosa125, Cosa150, LML Star 125/150, Stella 125/150

Malossi 177 Sport aluminum cylinders for Vespa PX125 and PX150

Malossi has extended its cylinder range for Vespa large-frame engines with 125-150 cc (Sprint, PX, Cosa, LML) with the three cylinder variants Sport 177 cc, MHR 177 cc and MHR 187 cc.

They have been completely redesigned and have nothing to do with their predecessor made of cast iron and only 166 cc. The aluminum used as the cylinder material makes the kit more thermally stable than the 166 cc cylinder and now allows a bore of Ø63mm. Externally, the cylinders are almost identical. All three versions use the same cylinder head and the same piston (the piston of the sports cylinder, however, has two piston rings). The formerly patented CVF II system has been dispensed with, but the overflow channels have been significantly enlarged. Adaptation to the engine housing is therefore mandatory for full power/torque.

MALOSSI 177 SPORT
The sports cylinder is aimed at users who also want to use their engine to the full in everyday use and therefore do not attach great importance to extreme peak power and revs. Malossi therefore uses tame timing angles that allow the cylinder to start early in the rev range. The large scavenging surfaces and the one-piece exhaust window, which is smaller than on the MHR, nevertheless allow a good and high torque with a sufficiently wide rev range.

• Strokexbore: 57xØ63mm
• Displacement: 177.59 cm³
• Exhaust angle: 173.5°
• Overflow angle: 115.5°
• Pre-discharge angle: 29°
• Pinch point: 1.0 mm (piston is 0.5 mm back at top dead center)
• Compression ratio: 1:10.8
• Overflow channels: 7
• Piston rings: 2
• Ignition timing: 18°f.Ot.

The cylinder harmonizes well with a revised intake with enlarged area/inlet angle and larger carburetor (e.g. SI24). A stable and well-suited crankshaft is, for example, the BGM Pro with 57 mm or 60 mm stroke. This has a moderately extended intake angle, which fits perfectly with a powerful engine concept that is fully suitable for everyday use. The BGM BigBox Touring or the Polini Box are available as exhausts. Both support the cylinder very well in the intended rev range and allow the full potential of the cylinder to be explored. Unfortunately, the Malossie exhaust is very loud, which makes inconspicuous riding almost impossible.

NOTE: The high bolt heads of the exhaust flange plate can get in the way of the exhaust manifold clamp. It is best to replace these from the outset with flat-head bolts (part number: 3333891)

(US211118)