We are in the midst of a revolution, given the vast choice of Lambretta casings available now for engine builders.
And I don’t think the tsunami has ended either. We hear rumours of at least one more performance engine casing coming for Lambretta from a famous name…
CasaCase Assembly video
Come the revolution
Most revolutionary amongst the new breed of engine casings is the CasaCase which is still the only one with a vertical split to load the crankshaft.
Fundamental to the project was housing a wider than standard crankshaft to eliminate the common problem of crankshaft twisting. With wider webs there is more metal gripping the crankpin and thus less chance of it twisting.
Currently the cranks for this project are assembled by top Italian firm Primatist and are included in the package. Several versions are available with either 110mm (standard for the CasaCase) or 120mm length rods and a choice of strokes ranging from 58mm up to 66mm. The largest stroke crankshaft currently accepted is 66mm although 68mm, 70mm and 72mm versions are being tested.
Fitting a wider crank into the engine and keeping the same carb and exhaust port positions (so standard off the shelf exhausts still fit) is not easy. It required moving the oilseals to outside the main bearings to gain space. The bearings are now lubricated by fuel/oil like most 2-strokes, rather than gearbox oil and grease on original Lambretta.
Lorenzo, Mickyboy and Tommy at Rimini Lambretta Centre, who designed the casing, put a lot of effort into finding new solutions to some classic Lambretta problems:
- The bush for the gear selector shaft has been replaced by a needle roller bearing with integral oilseals.
- The bendy 4-stud rear hub bearing retainer has been redesigned with an additional screw and a small o-ring to seal it.
- The ridiculously complex 8-piece system for sealing the stator wires in the mag housing has been replaced by a simple rubber grommet.
The over-riding impression I came away with was how much easier and quicker it is to build a modern engine casing. Something produced with highly accurate modern CNC machining is much more consistent than old Lambretta casings with variable tolerances from different factories.
Original Lambretta casings have often been passed down through generations of thread-wrecking bodgers, so building a tuned engine with one of those requires lots of laborious cleaning, welding and repairing before you start.
By contrast, using a new casing makes the process much more ‘plug and play’. If you want to see quite how different the layout is, and how easily it goes together, watch the video.
The CasaCase is supplied complete with a crankshaft, both main bearings, crankshaft oilseals, magneto flange, rear brake backplate and any specific fasteners.
Apart from that, the engine accepts all standard and upgraded Lambretta components for the rest of the ignition and drive train, and will accept original cowlings and exhausts.
- Provides a much more stable and strong base for tuning than any welded Lambretta casing.
- Hugely strengthened in known Lambretta casing weak-spot points such as the engine mount lugs and the rear underside area of the gearbox.
- Wider crankshaft webs used as standard to reduce chances of crank twisting.
- Supplied with a sealed roller bearing for gear selector shaft.
- Main crankshaft oil seals can be external extracted.
- Tested for a year in BSSO racing championship (winning Group 6), with no problems encountered with the casing at all.
- Vastly simplified system for sealing wiring through mag housing.
- Adaptable for Lambretta small-block, big-block and cylinders with many other stud patterns (dedicated SSR/SST 250cc and exotic cylinder conversion).
- Unsprung weight: CasaCase weighs 6.7kg, a standard casing weighs 3.9kg.
- You must remove the engine, or at least undo the engine bolt, in order to remove the crankshaft with a vertically split casing.
- Cost: while the CasaCase continues to be made in short batch sand-cast production it cannot be produced as cheaply as with a die casting.
- Crankshaft: a standard Lambretta crank does not fit. You must use a dedicated CasaCase crankshaft (supplied), though that is a substantial advantage in terms of strength over a Lambretta crank.
Price: Casing, crankshaft, bearings, seals and mag housing €1,955.00 VAT inclusive.
Availability: find your local dealer at www.casaperformance.com