On the test bench: Malossi 210 MHR

Malossi 210 MHR for Vespa PX 200

Since the middle of the year, Malossi has been producing two new cylinders, the Malossi 210 Sport and the Malossi 210 MHR, offered with 210cm³ for Rally200 and PX200.

In the meantime, the MHR version has proven to be a very powerful cylinder. Even without reworking the exhaust or the overflow ducts in the cylinder, the MHR provides a very high basic output for almost every engine setup.

New exhaust for Malossi 210 MHR

In order to bring the potential of the cylinder to the road in a mobile manner, an exhaust was developed for the MHR in cooperation with the exhaust forge Ludwig & Scherer, which helps the cylinder to develop powerful and controllable power.

As usual with Ludwig & Scherer, the exhaust has a sonorous name: Lara *

MHR 61mm stroke, carburetor Keihin 35 AIRSTRIKER, V-FORCE, CYLINDER inserted

For engines with high peak performance, a usable speed range and, viewed in terms of speed, early power, the best compromise has to be found for the performance curve. A major role in the resulting drivability is the course before the actual start of resonance. In the diagram above, 5000PS and 15Nm are already available at 20rpm before the power starts. The driving limit for this range is a minimum of 12 HP at 5000 rpm. Engines that provide less power in this speed range with the same peak power are subjectively rather difficult to drive on the road and have a pronounced “Reso kick”.

The Malossi 210 MHR cylinder responds very well to an outlet processing. Here a few more horses can be added to the herd without much effort.

Same engine as above, upper edge of exhaust raised by 1mm

But not only the absolute top performance is the MHR's profession, depending on the choice of exhaust system, other characteristics can also be achieved.

Here on a motor with rotary valve control and 60mm stroke. The cylinder is just plugged in.

Rotary valve 60mm stroke, Keihin 35mm Air Striker, Cylinder inserted

The rather high performance before the start of resonance at approx. 6000 rpm is bought at the price of less peak performance. On the plus side, there is a very smooth entry into performance.

The MHR cylinder is relatively short in the Malossi installation length, there is a piston protrusion on crankshafts with 60mm stroke. Therefore, depending on the desired engine characteristics, a spacer is required for the cylinder head.

The use of Spacers on the cylinder head very easy. The two holes in question for the centering sleeves can easily be expanded to a diameter of 9,4mm. As a result, the spacer is centered on the cylinder bore and the protruding piston does not come into contact with the cylinder head gasket.

A very useful variant with a 60mm stroke has turned out to be a spacer at the cylinder base with 1mm and at the (MHR) cylinder head with 0,5mm. The pinch edge should be checked in any case.

If the cylinder is only to be underlaid at the base and the outlet is to be machined in order to achieve high peak performance, the MHR is also able to convert very high control angles into mobile performance thanks to the revised overcurrent system. Values ​​around 136 ° overcurrent angle are not uncommon and work very well, depending on the perephria.

CONCLUSION

Anyone looking for top performance should go with the Malossi 210 MHR be well served.
Without a lot of reworking, with the appropriate component selection, very remarkable performance values ​​can be achieved. The Malossi cylinder head is a good choice for almost all combinations and, due to the convergent design, it should be fitted with a 57mm stroke with a pinch edge of 1-1,1mm and with a 60mm stroke with approx. 1,2-1,3mm.

* The exhaust from Ludwig and Scherer is expected to be available in a left-hand version from February / March - we will keep you up to date.