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Balancing Crank Assembly


The flywheel assembly should be balanced to minimise the forces that would occur from an out of balanced assembly.  This mainly helps the engine run smoothly.  An out of balance assembly increases wear on the bearings, increases vibrations throughout the engine and can reduce the engines power output.

Replacing the flywheel with a modified lightened one will lighten the crank assembly.  This has an effect of reducing the inertia of the heavier flywheel, allowing the engine to revolve easier, soaking up less of the produced power.  However this loss of inertia also makes this engine easier to stall at lower revs. 

Regrind crank – The crankshaft undergoes high loading due to the fact it transforms the linear loading of the pistons into a usable rotational motion.  In time it will wear.  Rather than replace this relatively expensive forged item the surfaces can be reground.  This regrinding is a specialised process as the grinding wheel needs to travel horizontally while the crank rotates.


Blueprinting of an engine refers to a set of standard measurements or ‘blueprints’ produced for competition engines to keep the modifications as standard as possible.  This leads to closely matched competition between competitors, keeping overall costs down.  It is possible to maximise the power of the engine by building it around the maximum prescribed tolerances, therefore keeping the engine legal within the regulations for racing.  Here at AMAC Engineering we can obtain the engines measurements from homologation papers and build the engine with maximum attention detail to the higher prescribed tolerances.


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