MPL Molnar Manx 90 Bore Specification

All parts are machined from original castings to ensure authentic appearance, whilst the revised bore & stroke permit a worthwhile improvement in performance.

90mm bore x 78.42 stroke = 499cc

Pressed up crank assembly, with integral mainshafts, made from EN36 forgings hardened and ground all over. 40mm parallel pin and INA needle roller big end bearing. We use Carrillo con rods. We believe that these proven crankshafts give the optimum combination of rigidity and flexure for the Manx.

Special forged 2 ring piston, running in a ceramic bore in a lightweight barrel casting. Maximum safe RPM = 8,200.

Revised and updated compact combustion chamber machined from castings made from original Norton patterns. Inlet valve 2” diameter. Valve angles reduced to 60 degrees inclusive with valves repositioned to suit. Compression ratio up to 13:1 can be achieved but the efficient combustion chamber design allows the use of 100 octane unleaded fuel. Minimum carb size 1.1/2” (38mm). Single, near central spark plug with twin spark option. Revised detail machining of cambox castings to allow for improved cam profiles and neatly enclosed valve springs.

Almost every part has been worked on to reduce the weight of the engine to 78 pounds (35.5 kg) excluding magneto and carb.

For countries where it is permitted, this engine can be supplied 2mm oversize on the bore to give 92mm bore x 78.42 stroke = 521cc.

MPL Molnar Manx 90 Bore Specification

For pricing information for 90 Bore Manx', follow this link