The MCE-5 crankshaft has half the crank radius of aconventional engine crankshaft with the same piston stroke. Asa result, with the same bore and in-cylinder pressure, the MCE-5crankshaft is twice as loaded as the crankshaft of a conventionalgasoline engine.

The crank radius of the MCE-5 crankshaft is reduced by half andthe overlap between the crank pin and main journals isincreased. This made it possible to eliminate the crankshaftcounterweights without increasing its average bending. TheMCE-5 crankshaft is supported by a particularly rigid bearingline situated in the crankcase. This rigid crankshaft-crankcaseassembly ensures a long service life for the MCE-5 VCRi engine,despite the extremely high loads that it is subjected to. Themaximum stresses applied to the MCE-5 crankshaft and theresulting safety factors remain “consensual” and compliant withindustry standards. The elimination of the MCE-5 crankshaftcounterweights leads to an engine length that is identical to thatof a conventional engine with the same number of cylinders andthe same bore.

Working in conditions close to those of a highly loaded Dieselcar engine, the manufacturing and the operating environment ofthe MCE-5 VCRi crankshaft are comparable: it is forged andsupported by high-pressure bearings. The forging of the MCE-5VCRi crankshaft is made easier by its small size and theelimination of the counterweights, which require thedisplacement of forged material far away from the center ofgravity. The MCE-5 VCRi crankshaft is 30 to 35% lighter thanthe crankshaft of a conventional engine with the same cubiccapacity.

MCE-5 VCRi: Pushing back the fuel consumption reduction limits

Crankshaft

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The MCE-5 VCRi crankshaft has a crank radius half thatof a conventional engine with the same piston stroke

Because of its high natural rigidity (big bearings overlap),the MCE-5 VCRi crankshaft no longer requires counterweights

MCE-5 VCRi: Pushing back the fuel consumption reduction limits

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Because it is compact and has no counterweights, the MCE-5 VCRi crankshaft is 30 to 35% lighter than a conventional engine crankshaft

DimensionsInterbore (mm) 86Crank lenght (mm) 21Crank pin diameter (mm) 50Main bearing diameter (mm) 60Bearing N°2 axial clearance (mm) 70 < < 181Main bearing diametral clearance (µm) 45 < < 95Weight (g) 10,400Operating conditionsMaximal crank stress (N) 108,000Maximal main bearing stress (N) 70,000Production technical dataMaterial GKHProduction process Forging + grinding

The main characteristics of the MCE-5 VCRi VCR crankshaft