Lambretta Technical Section
CHIMERA – TWIN CONVERSION KIT BICILINDRICO: presentation
Why was Chimera born?
Chimera was born from the dream of being able to drive a twin-cylinder configured perfectly as desired.
The advantage of Chimera is the use of the original crankcase and all the original transmission components.
The great configuration versatility allows you to choose the engine you want most and…do x 2!
Chimera was studied, designed and built with the idea of giving the customer the opportunity to configure the twin-cylinder according to their needs and performance searches.
Chimera is installed on Lambretta LI S1 S2 S3 – TV2 – TV3 – LIS – SX – DL models.
The Chimera kit is available in the version:
On the Chimera product page you can find the photos and the description of the kit components. Below we will analyze some components specifically.
Let’s start at the heart of Chimera: the fusion block
The casting aluminum block is analyzed by tomography (x-ray of the casting block) to ensure the quality of the casting and to avoid the possibility of weak areas or blowholes within the material.
Each casting undergoes a specific stabilization heat treatment in order to ensure perfect stability of the product in the face of high operating temperatures.
The block is subsequently worked on 5–axis CNC machines following the 3D design obtaining a precision machining of 0.02mm.
Ground double shaft complete with silver plated roller cages
The crankshafts are CNC machined, machined, ground and electronically checked to verify their zero balance.
The connecting rods are of excellent workmanship and ground in parallel to ensure excellent machining efficiency and use. coppery 107 mm rod and 58 mm stroke
The couplings take place through the use of high hardness screws and Nord-lock anti-rotation components.
Designed and built to be able to support extreme displacements, the double shaft uses a system of calibrated anti-rotation pins which guarantee excellent functionality and balancing of the engine without the risk of misalignment.
Ducati Energia variable timing electronic ignition
Thanks to the presence of two pick–ups at 180°, the Ducati Energia variable timing electronic ignition guarantees perfect symmetrical behavior for both thermal units.
The 12 poles offer pleasant driving stability and excellent current delivery.
The ignition group is supplied with all the elements necessary for installation: 2 cdi, 1 regulator and all the brackets to house the components. The brackets are custom made based on the Lambretta model.
The flywheel, machined from solid, is perfectly balanced and has a weight of 1.6 kg which, thanks to the two cylinders, guarantees excellent progression while maintaining a pleasant regularity of motion even at low revs.
The advance scales expressed in degrees are shown on the flywheel.
These scales help during installation to determine the new reference point and, thanks to the strobe gun, it will be possible to verify the phase degrees in an instant!
This innovative system guarantees precision in the phase adjustment of the twin-cylinder.
CNC cylinder heads with self-centering bushings
Chimera heads are the maximum development for cooling and high efficiency for the cylinders.
They are machined from solid and milled on specific request in order to obtain a 35% more radiant cooling surface compared to an original head.
On the base of the heads there are sealing grooves which allow the head gasket to expand in the cavity and ensure maximum pressure tightness.
Heat treated to ensure temperature and steady state stability. Perfect flatness of the tops even at temperature!
Centering, locking and sealing are guaranteed by the use of brass bushings and nuts. The property of the brass, thanks to the low expansions, offers a good closure between the head and the cylinder, avoiding leaks.
Reinforced cooling cap
The cooling cuff has been the subject of much flowmetry study. The challenge: to provide equal air distribution and fresh air to both cylinders.
The use of increasingly sophisticated software has allowed a simulated flow analysis with engine, operating temperatures and variation of the air flow based on the rotation speeds.
The interweaving of these data, 3D and bench tests have made it possible to create the optimal cooling system for Chimera.
The headset is fiberglass reinforced at the mounting points with a high strength Kevlar weave to ensure strength at the stress points.
Avional CNC rear wheel spacer
The wheel spacer keeps the cylinder – frame alignment symmetrical and the engine centred.
The spacer, made from the best high–strength aluminum on the market, is fixed to the rear drum of the wheel (use drums only for S3 LIS DL models).
Thanks to the CNC design, it was possible to create a stop tooth that allows perfect support and centering of the wheel.
It is possible to use both split rims and CNC rims. Based on the powers that can be reached, we recommend CNC rims.
Shock absorber support
Support and fixing screws created on specific 3D modeling.
The support is used to fix the rear shock absorber in the same original area.
The support can house all types of rear shock absorbers.
