VMC Explorer 244cc Engine Kit + Malossi Reed Valve Crankcase + SIP 60 Crankshaft

VR-ONE REED VALVE

The VR-One is for power purists, for those who want to push their Vespa to the limit, but not only. It has the same assembly characteristics in the body of the V-One and the same cylinder housing possibilities thanks to the revised fluid dynamics of the crank chamber, the drilling of the studs and the same accessories supplied with the V-One (with the exception of the mixer pin).
This crankcase has been designed to withstand higher powers and for this reason it is supplied with main ball bearings on the flywheel side Ø25xØ52x15 and transmission side Ø25xØ62x12, which eliminate the needle bearings and allow for greater capacity to withstand radial loads and additional resistance to axial loads, not contemplated with the original roller bearings. Dedicated oil seals are also supplied.
The greater resistance to stress due to the crank mechanism makes the crankcase perfect for assembly with our single-ring MHR cylinders, item 3116349 (stroke 57), but above all with the kit 3116351 (stroke 60). The natural combination for this configuration is with the Malossi crankshaft with full shoulders, stroke 60, item 5316176, supplied with the right balance and perfect for the reed valve supply planned for the new VR-One .

Reed valve power supply

This is where the major innovation and sporting orientation of the crankcase lies, now powered by a system SUPPLIED ENTIRELY with the reed valve assembly which, thanks also to the new high-quality carbon fibre reeds, guarantees an increase in power across all operating speeds and at the same time allows the highest speeds to be reached.
The assembly consists of a die-cast valve seat, coupled to the crankcase surface with a seal guaranteed by a special gasket, and a completely new reed valve equipped with a multiple-profile diffuser, specially designed with fluid dynamic simulation programs and featuring a particular shape of the side walls capable of both eliminating part of the turbulence, which is normally created when the air-petrol mixture passes through the diffusers, and at the same time directing the charge in the correct direction, once the reeds are opened.

The fuel manifold, designed according to the X360 technique used in our competitions, is made up of a die-cast flange connected to a Viton union by tightening a profiled lip, which guarantees a perfect hermetic seal, and at the same time allows the union to be turned in the direction desired by the user so as to perfectly orient the system according to the shape of the vehicle.

The sleeve has a 30mm inlet diameter. The ideal match is the Dell'Orto PHBH 30 carburetor (not supplied).

Malossi has decided to make a clean break with the past to create an iconic component for an equally iconic vehicle like the Vespa PX200E! Making the most of all the technology and knowledge acquired along the roads and tracks of the world, Malossi has developed the new V-One and VR-One crankcases. The design, study, research and production of these crankcases are the way in which Malossi intends to pay homage to the enthusiasts of these vehicles. The two models give the opportunity to preparers, restorers and, more generally, to all owners of a Vespa PX200E to indulge themselves and choose the modification path best suited to their needs:

• The amateur, the restorer, the traveler and the simple Sunday tourist, looking for a component that can be perfectly replaced with the original, that does not require any modification to the vehicle and offers the maximum choice of components, from the original to the main items on the market, will have the V-One SPORT crankcase at their disposal.
• The tuner looking for maximum performance, the best internal fluid dynamics and the greatest possibility of engine development can purchase the VR-One MHR crankcase

TECHNICAL FEATURES

Made entirely in ITALY

The technical and technological advancement of Malossi is the greatest strength of our products, the reason why we are convinced that we have created one of the best crankcases ever produced.

Strengths

In every square millimeter of the crankcase you can perceive an innovative thrust that catches the eye even of the most inexperienced of tuners. The gravity shell casting, which differentiates these crankcases from the original models obtained, instead, with a die casting process, combined with the use of modern shell moulding cores, allows to obtain better internal shapes and made with the utmost precision.
Gravity casting has allowed us to strategically increase the sections in the most stressed areas and to subject the crankcases to a post-casting tempering treatment, thus obtaining very high mechanical resistance. These products are made with a very high quality light aluminum alloy Al Si 7 Mg (EN AB and AC 42000) containing the right quantities of: Silicon, to increase mechanical resistance, Manganese, for better resilience and corrosion resistance, Copper and Magnesium, to improve workability.
The crankcase machining is performed entirely in our workshop with CAD/CAM process and carried out inside high-precision CNC work centers. All the support and closing surfaces have been machined with diamond tools capable of guaranteeing extremely low surface roughness values and practically perfect couplings.

Advantages

Both crankcases share a series of basic features such as, for example, the front arm reinforced with stress-relief ribs and sections with a calculated profile to allow the correct flow and channelling of stresses and guarantee better resistance.

Both models include brake shoe pins, which are installed directly in the company with presses capable of applying the forces necessary to create the couplings requested by our designers.

In addition to the brake shoes, the crankcases are supplied with the M7 studs required for fitting the gear selector.

Finally, no version excludes the original electric starter, whose actuator can be mounted in the appropriate plane obtained in the volute.

Fitting the crankcase to the vehicle does not require the purchase of any additional components, in fact both versions are equipped with both front Silent Blocks in the arm connecting to the body and a rear anti-vibration mount connecting to the shock absorber.

Fluid dynamics has finally been implemented! Having equipped our series models with transfer bags adequately profiled and sized to perfectly match our Ø 68.5 cylinders, without however excluding the possibility of mounting other thermal groups and indeed offering an increase in performance even with the latter, exempts tuners from the obligation to work on the crankcases to mount higher performance cylinders. The M8 studs for mounting the cylinders are also included in the package!

Thanks to the interventions listed, achieving greater power is no longer a problem. Even the usual inconvenience of oil leakage from the crankcase has been solved thanks to:

1. Increased pump casing walls, which also further contributes to the mechanical resistance of the casing
2. Using M8 stud bolts instead of the original M7 ones
3. Extremely high precision machining of the closing surfaces. We have eliminated the crankcase gasket, which deteriorated and was the main cause of oil leaks. Now the crankcases are perfectly coupled and closed with gasket paste, resistant even to the highest operating temperatures!

We didn't want to stop there! After assembling and disassembling original crankcases for years, working on them and trying out thousands and thousands of solutions to propose constantly updated components, we came face to face with inefficiencies and inconveniences that we analyzed to propose our solutions: this is the case of the crankcase tightening system, which in the original components is made with the classic screw-nut system, notoriously uncomfortable and not very user-friendly for the user.
Such a valuable vehicle deserves the best possible maintenance and this involves the need to assemble and disassemble the various components to replace them or even just to check their correct functioning, overhauling them when necessary. Anyone who has touched the original crankcases without disconnecting the block from the vehicle has certainly encountered the difficulty of manipulating the components that make up the block due to the awkward and difficult to reach position of the nuts, which, once unscrewed, risk falling to the ground and getting lost who knows where. Our solution is as simple as it is sophisticated: eliminate the nuts!
By making the threads in the left crankcase (or transmission crankcase) and the seats in the right side (or ignition crankcase) we have eliminated the need for nuts to tighten the two components. To prevent the screw from being accidentally knocked or damaged during operation, with the risk of ruining the thread, where possible we have made seats on the right side that allow the screws to be fully recessed, thus protecting them from any danger.

for Vespa 200 Rally VSE1T 33997 ->/​P200E/​PX200 E/​Lusso/​MY/​Cosa

• Rotary disc valve
• Stroke: 60.0mm
• Connecting rod: 127.0mm
• Race - connecting rod
• Connecting rod bearing: 16x20x20 mm
• Piston pin Ø 16mm
• Timing: 115°/4° at TDC
• With fine balance
• With tungsten counterweight

Tuning Road - suitable for everyday use

A high-end crankshaft for 200cc Vespa models. Increased stroke combined with the highest quality for torque-oriented, road-going Engineized tuning.

Along with the cylinder and piston, the crankshaft is the beating heart of any internal combustion engine. It is one of the hardest working components and the conversion of the piston stroke into a rotary motion places the highest demands on both quality and attention to detail during construction.

The crankshaft should also be well balanced to reduce any unwanted vibrations and oscillating mass kept to a minimum to support efficient delivery of the power created by the engine.

The large end bearing rotates at the same speed as the engines RPM, receives lubrication from the gasoline/two-stroke diesel mixture, and must accommodate two sharp changes in piston direction for each engine revolution.

The crank pin, connecting both crankshaft legs to the connecting rod, must be pressed into the cores with a certain distance from the openings in the cores. If this connection is not strong enough, the crankshaft can spin and the crankshaft webs become misaligned and seize.

To ensure that the big end bearing receives sufficient lubrication, the big end of the connecting rod should be provided with slots to facilitate this.

The crankshafts available in this range can be divided into two main types. The "Premium" ones are equipped with a high-end "standard" type of connecting rod, which means that its surface finish remains unchanged. It is equipped with grooves and lubrication holes, for the large and small bearings respectively.

The "Performance" crankshaft models include a very high quality connecting rod and are made more durable with an intensive polishing procedure that provides a more stable molecular structure. The smooth and polished sides of the connecting rod also help reduce turbulence. The polished connecting rods have also been optimized with a reduction in weight. They have a gas flow profile and have been modified around the big end to improve bearing lubrication.

PX 60mm long stroke crankshaft

The 60mm stroke provided by the long stroke crankshaft for the Vespa 200cc models has 3mm more stroke than the original crankshafts. This increases the cubic capacity of the fitted cylinder by about 5%. The improved stroke to bore ratio not only increases power but also significantly increases torque output. The crank is designed to improve torque-hungry road engines and the inlet port timing on the disc valve band is only slightly longer than on the original type. This allows the engine to maintain decent low-rev performance and is also relatively simple to set up correctly. The ‘blowback’ from the crankcase is also kept to an acceptable level. The disc valve disc is specially designed to make the gas flow through the crankcase more efficient.

Another aspect in the development of crankshaft networks was to provide more effective balancing and a smoother running engine.

Bottom line: The ideal crankshaft for delicate and reliable tuning projects.