Cylinder head -MALOSSI 210 cc Sport / MHR- Vespa P200, Rally200

Malossi H.T.S.R. Cylinder Head for 210 cc Vespa Tuning

The H.T.S.R (High Turbolence Squish Racing) Malossi cylinder head for the 210cc cylinder was already introduced in 2008. For the Malossi 210 Sport and Malossi 210 MHR it was only completed with holes for the centering bushes used there. It works with a narrow distance to the piston crown (the so-called squish edge) of approx. 0.9-1.0mm. This perfects the efficiency of the squeezing effect at the outer piston crown zone. The narrow squish edge ensures that as little mixture as possible remains in the squish area, which has a very positive effect on performance. Furthermore, detonations and engine ringing due to self-ignition are effectively avoided and the mixture is again vigorously swirled through before combustion. The result is a clean combustion, even in the lower speed range, as well as a better thermodynamic efficiency.

The compression of the head is with 57mm stroke and 0.9mm squish edge 11.5:1. Due to the cleverly constructed squish edge, the head is nevertheless very well drivable on engines with strong resonance exhaust systems. If the engine is equipped with a 60mm long stroke shaft, the compression ratio increases to 12:1 (assuming the same squish edge), an enlargement of the squish edge to 1.3mm reduces the compression again to 11.5:1.

Combustion chamber volume: 20cm³ (0.9mm squish edge)

Recommended squish edge: 0.9-1.3mm

Compression 210cc: 11.5:1 (QK 0.9mm)

compression 221cc: 12:1 (QK 0.9mm)

spark plug: long thread (Bosch CC or NGK ES)

centering bush bore: Ø11mm (bushes not enclosed)

Note: Due to the special piston crown curvature of the Malossi 210 (outside with an angle that changes to a curvature towards the inside) the cylinder head has a slightly negative squish edge. This is intentionally designed and not a manufacturing defect. It helps to cool down the highly stressed ring zone of the piston and thus provides even more stability of the cylinder.

TIP: The centering bushes are also available separately (see accessories) so that the head can also be used on other cylinders (with Malossi piston or its piston crown). So the old Malossi cylinders can also be combined with this head and can be optimally centered on the cylinder through the fitting bushes (bores on the cylinder must be widened).

US

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