Re: REBUILDS

[jlandry@domain.elided (John A. Landry)]

In a brilliant stroke of genius, Doug Rasmussen
<DougRasmussen@domain.elided> blurted out:

>  Exactly how do they balance an engine like an IH?  Maybe, dynamic balance
>on the rotating components like crank?  And just equalize the weight on the
>reciprocating components like pistons/rods?  Wonder if completely assembled
>and running engines are ever dynamically balanced?

Doug,

It's my understanding that they start by weighing each piston with ring
set.  They find the lightest piston and then proceed to remove metal from
the remaining pistons to make them match.  Next using a special jig and
scale, they weigh each *end* of the connecting rods and modify them so all
the weights on each end are the same.  Then they clamp weights to the
crankshaft (to duplicate the effects of the connecting rods and pistons)
and they proceed to dynamically balance it by adding or removing metal as
required.  At some point they dynamically balance the flywheel or flex
plate.  And lastly they check the dynamic balance of the entire crankshaft
with the harmonic balancer and flywheel attached.

The result is a very smooth rotating and an almost vibration free engine.
The crankshaft and other components are said to be subjected to much less
stress... especially the front and rear main bearings.

Regards,

John L.
-------------------------------------------------------------------------- 
jlandry AT halcyon DOT com       | TEENAGERS: Tired of being harassed by
Conservative Libertarian         |            your stupid parents?   
Life Member of the NRA           |
WA Arms Collectors               |                ACT NOW!
Commercial Helicopter - Inst.    | Move out, get a job, and pay your own
http://www.halcyon.com/jlandry/  | bills while you still know everything!