Many Vespa fans consider the smallframe models motor to be the finest amongst those produced by PIAGGIO. For this reason, and many more, we have decided to have revised and updated versions produced.
The SIP smallframe motor cases are, despite their extensive strengthening, almost identical in appearance to the original items. These essential improvements qualify this motor as a first choice when replacing/upgrading your original, or as a basis for any ambitious tuning project.
Both the transfer and inlet ports share their internal dimensions with the originals, with lots of potential for reshaping and enlarging. The material surrounding these areas has been increased to facilitate 'out of the box' port enlargement work, without the need for any extra material to be added by expensive welding. The disc valve inlets sealing surface has also been increased and can now be enlarged over both motor halves. The openings for the casing bolts on its lower half have been relocated externally to allow enlargement, which in turn facilitates the use of crankshafts with larger webs and/or increased stroke. The reinforced swing arm assembly has been intensively laboratory tested and approved for its durability in all situations and resistance to cracking and breakage. In addition this new motor type was successfully test-run at almost full-throttle for two whole weeks in combination with a POLINI 133cc cylinder, 24mm carburettor and a PM exhaust. All temperature, corrosion and road tests were also passed with flying colours and the customer feedback also helped refine the final product of our labours to perfection. The overall design is based upon the PK range motor, with a three stud inlet manifold mounting and the exhaust mounting opening located on the lower side of the swing arm assembly. If a Vespa 125/PV/ET-3 motor is being replaced our Serie Pro manifold adapters (inlet : #21500060, #2150007-, #21500080) can be used to ensure compatibility. Another upgrade is the use of high-end Italian produced motor mounting bushes for a tight suspension. Before being dispatched in a sturdy double-strength box these motors are carefully checked for correct dimensioning, production quality and completeness by one of our team.
We have two versions of these motor cases available, the main difference being the diameter of the area where the flywheel side bearing is located. : Motor #24320000 is compatible with the ETS series crankshaft and the PX bearing. - Motor #24310000 is suited for use with the bearing fitted to all Vespa 50-125/PV/ET-3/PK 50-125 motors with its 47mm outer diameter. Top quality castings and surface finish.
Conclusion: your smallframe is no longer at risk of dying due to engine damage. And at a very good price / performance ratio!
- Original appearance and port dimensioning, oversized gasket surface areas, extra material included to enable extensive port/crankcase enlargement.
- The cylinder base gasket surface area has been spread over both motor halves facilitating maximum gasket area following port enlargement.
- Increased motor case thickness and internal ribbing, reinforced crankcase and swing arm assembly.
- Fits for Vespa 50-125/PV/ET3 (manifold adapter) and PK models
- Two versions are available. : The flywheel side crankshaft bearing seat diameter with either 47mm (for crankshafts with a 20mm crankshaft bearing seat), or 38mm for the 25mm ETS crankshaft.
- The swing arm assembly has been restructured and reinforced along its inner edge and compatible with all 3.00 – 3.50/10 sized tyres. 3.50-10” tyres fit without modifications.
- The seat of the primary drives bearing seat has also been optimised and possesses a diameter of 57.5mm for compatibility with all suitable primary drive/repair kit types.
- Overall construction laboratory and road tested and optimised for rigidity and durability.
- Replaceable bronze sleeve for the gear selector shaft.
- Engine studs for the brake assembly, the motor casing halves (2x) and mounting studs suitable for a 125cc cylinder are included in the delivery.
- Internal kick-starter buffers and rubber bushes for the swing arm and shock absorber mounting assemblies are also included and pre-mounted.
Paolo Pavanati, PARMAKIT, Italy,15.07.2016:
"We tested the crankcase you sent us and we are satisfy, we used in Polini cup sunday with good result."
GSF User, 'Mike', Germany, 29.04.2016 :
"I've already got one of these in action! A great set of engine casings with an enormously long disc-valve opening ;-)"
Et3.it community user ROS04, Italy, 21.08.2016 :
"In my opinion SIP have really hit the mark with this top quality item! With an investment of only € 460,- you have a completely fresh set of cases to modify as you please, without the problems encountered with the original items!"
Et3.it community user $ aplus, Italy, 02.05.2016 :
"At last I can get to work effectively with my Dremel! This material doesn't clog or get sticky, It can even be CNC machined with no problems!
SIP Customer MaNiAc, Germany, 13.06.2016 :
"At last a top quality set of motor casings with a normal width, perfect for use as a basis for any racing motor projects! The QUATTRINI casings have a lot less road clearance than these new SIP versions! Thanks SIP!"
SIP-TIP: Do not forget the gasket set, oil seal, bearings, woodruff key and gear oil! A new case also likes new engine screws and bolts. If you have a crankcase with only a two-hole fixing, you can take advantage of our conversion manifolds (21500060, 21500070, 21500080).