
Originally Posted by
RallyBob
This surprises me as I have retrofitted custom 3” aluminum crank pulleys to 2.2’s and spun them over 9000 rpms and they were always smooth as silk. No harmonic balancer.
However all components were always balanced beyond factory specs. Crank/rods/pistons/flywheel.
Not surprised that they are smooth as silk, Bob. A balanced damper does not provide any balance contribution to the engine balance (i.e., 'butt-feelable' engine vibrations).
But that is a separate matter from internal torsional crank vibrations that a damper is designed to keep under control. I cannot say what any particular 2.2L solid pullies have done in that matter, but crank breakage when replacing dampers with solid pullies is a real issue that does occur at times. It's not guaranteed to happen, and usually takes some operating time to happen if it does; but just because some cranks of a particular type survive without a damper, does not mean all cranks of that type will do so. The engine design engineers decided that the 2.2L crank and engine design was such that the internal crank vibrations
could be an issue so included a damper for production. Maybe they over-reacted and a damper function is not really need for the 2.2L? I dunno....
FWIW (And you can stop reading if you are bored with my comments on this! LOL)..... Everybody here needs to realize that crank damping and engine balance are 2 entirely different matters. This all gets confused by the term 'harmonic balancer' that gets thrown around. If the pulley or damper is balanced by itself, then it does nothing to contribute to
engine balance. A pulley or damper has to be imbalanced in a specified way to be a part of the engine balance.
Damping is a separate design issue, and typically involves a 2 part damper/pulley, with the outer ring connected to the hub with an elastomer ring. There are other damper design types (look up 'Fluidamper'), but this is the typical production design; it's cheap!
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