For competition machines with MBK 51 chassis (Also available in G3 version with high engine center distance 52X52mm)
Here are the excellent MVT G2B housings, 43X50mm center distance like the original
Whether in terms of aesthetics or performance, these are real partitioned competition cases! These crankcases are entirely designed for pure performance!
Their solidity will allow them to withstand the greatest powers without breaking, they have a gas vein, a perfectly designed intake!
Here is the information needed to build your G2 competition engine on your MBK 51:
- The crankshaft can be the MVT SC reference VI42 long stroke 43mm connecting rod 90mm or, if you want a real G2 engine, the MVT SC G2B connecting rod reference VI41 short stroke 39.7mm connecting rod 85mm.
These two crankshafts are mounted in the crankcases with standard 6204 bearings and MVT oil seals reference SPIG234. On these crankshafts, you can mount MINARELLI AM6 cone or standard DERBI cone ignition rotors, on the variator side, you can mount large cone competition variators such as MALOSSI MG / MVR, BIDALOT and others.
- The high engine to install is a high engine with a 42X50mm center distance like the original! You can therefore install tall standard MBK 51 engines with the 43mm long stroke crankshaft (you will need to adjust by 5mm for the connecting rod length because this crankshaft has a 90mm long connecting rod). Nothing prevents you, therefore, from installing a large diameter high engine to make it an 80cc on the long 43mm stroke! For a real G2B, install a G2B BIDALOT or MVT cylinder reference HM 36, therefore a high engine with original center distances of 43X50mm but specifically designed for the 39.7mm stroke of the competition crankshafts.
- Ignition, you can mount MINARELLI AM6 / DERBI cone level ignitions on the MVT crankshafts provided for these crankcases, but you will need a custom plate. Otherwise, there is the complete MVT DIGITAL DIRECT DD25 ignition or you can mount an MVT DD from MINARELLI AM6 / DERBI using the PLA17 ignition plate specifically designed for these crankcases.
- Intake, MVT has provided a fairly standard intake to find, it is the same intake which was installed on the POLINI PANTERA, MINI MOTO competition engines... The center distance is therefore the same as on the POLINI crankcases of PEUGEOT 103 / MBK 51 with incorporated support. These are valves 144.405.003. You can obviously put another intake if desired, but MVT recommends this valve on the G2B! Pipe level, you can take a pipe with this center distance or pinch the valve with a DERBI center distance pipe!
- Fixing the mainspring, you will use the MVT support reference RCG2B 51
In any case, keep in mind that this type of assembly requires adaptation and work, nothing is really "plug and play" on competition engines!
