Long Stroke Crankshaft SIP PREMIUM

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

• disc valve
• stroke 60,0mm
• conrod 110,0mm
• Sport - con rod
• Connecting rod bearing: 16x20x20 mm
• pin 16mm
• valve timing: 125°/-5° post TDC
• fine balanced

 
TUNING SPORT - high-performance

PRODUCT DESCRIPTION

High End crankshaft for Vespa large frame models. Highest quality long stroke crank for torquey fast road engines

 

The crankshaft, together with the barrel, is the heart of the engine. It is one of the highest stressed components of any motor. The translation of the up and down strokes of the engine into a rotation requires the highest standard of quality and manufacturing. Hence the crankshaft should be well balanced to reduce vibrations. Translatory mass should be low to support the engine’s performance. The big end bearing rotates at the speed of the engine. It’s lubricated by two stroke oil and needs to deal with the stresses of the piston changing its direction of travel twice per revolution. The big end pin which connects the two crank webs needs to be just the right size for a reliable press fit. If it is undersized just a tiny little bit chances are the webs will start twisting. To make sure the big end bearing is adequately lubricated the big end eye of the conrod should be slotted for the oil to get to where it is needed.

• Smooth running
• Highest quality materials, manufactured to the highest standard
• Available with a polished conrod

The SIP Crankshafts

SIP’s line of Crankshafts is made in Italy, we made sure our cranks meet even the most exacting expectations one could have for a crankshaft. We took extra care to deliver the highest quality and the best design possible. Each type of crankshaft is balanced with the stroke, the conrod length and the model of scooter it fits in minds. There are two versions of the crankshafts. The Premium models come with a high quality conrod with an unpolished surface. The conrod does not have any lubrication slots or drilling.

The Performance cranks feature an extremely high quality polished conrod. The polishing structurally strengthens the conrod by removing any roughness which otherwise might rise local stress. In addition to the polished conrod causes less turbulences. The polished rods are also lightened, their oval section is gas flowed, and they are modified around the big end to ensure better cooling and lubrication of the big end bearing.

The Longstroke crank P Range 60mm

The longstroke crank for the Vespa largeframe engines comes with a stroke of 60mm. That’s 3mm more than standard. This increases the engine capacity by about 5%. With the improved bore/stroke relation you do not only get more power but more torque in particular.

The crank is designed to ideally complement a bottom end torque road engine driven daily. The cranks with 60mm stroke are a straight fit to the engine, no modifications of the crankcase required.

The inlet timing rotary valve

There are two versions of the rotary valve crankshafts:

• 115°/4° inlet timing: pretty much as per the original, which lends itself for a mild road tuning.
• 125°/-5°inlet timing: that’s 20° more than the original crank. The longer inlet timing is an ideal basis for a sportier tuning. The inlet timing is still in a range though that works well for everyday use. The engine doesn’t lose at low revs and is still easy to set up with little sprayback from the crankcase. In addition to that the inlet side of the crank is optimised so as to ensure good gas flow.

With the crank’s webs designed like that it is also possible to balance the crank more efficiently which makes for an exceptionally smooth engine.

The conrod length

We supply the crankshafts with different conrod lengths:

• 105mm: for 125-150cc Largeframe Vespa
• 110mm: for the 200cc King Size Vespa
• 127mm: ideal for the QUATTRINI M 244/M 232 kits. The extra millimetre of conrod length gives you a bit of wiggle room to play with the port times.

Attention: The rotary valve of the SIP crankshaft has a particularly precise fit for a smooth engine run. In connection with aftermarket housings or faulty rotary valve surfaces in the housing, the crankshaft and housing may come into contact. Please check the dimensional accuracy before installation.

 

Conclusion: The ideal crankshaft for mild and reliable tuning projects. Works well for anything between a lightly tuned engine to a Malossi Sport Kit with a big-box exhaust and some real-world and motorway-usable 20 Bhp.

The Best Setup - Our SIP-TIP:

• Do not forget to also replace the crankshaft bearings and oil seals when upgrading the crankshaft! i.e. Art.-No. M6615466 and M6617236.
• Compensate for the extra stroke with a 1.5mm head gasket or use a cylinder designed for 60mm stroke (Art.no.: 15060000).
• New and reinforced woodruff keys are always a good idea: Art.-No. 87059200

 

The timings stated above were determined viewing in the direction of the clutch side. That means: "138°/6° after TDC: Inlet timing begins 6° after the crank pin and stays open for 132°.

 

OEM numbers (for comparisons): (PIAGGIO)

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