<VV> Rod caps and balancing

[John Kepler]

"This is why the 'Vair crank has no counterweights." 

What crank are you looking at?????  The 140 crank I have sitting on the
bench in from of me sure as hell has "counterweights!


"If the pairs of rods shared a journal, the crank would MANDATE
counterweights or the engine would rattle itself out of the engine bay in
short order."

Do a Google search on: "Secondary imbalance" and "Tertiary imbalance".  Just
because you balance and counter-weight the crankshaft, doesn't mean the
engine won't vibrate like a rock-crusher.  An in-line 4-cyl has a tertiary
imbalance that causes the engine to want to oscillate  "up-and-down".....a
V-6 wants to oscillate "side-to-side" along a axis parallel with the
crankshaft.......V-4 have a weird pivotal movement along a vertical axis
perpendicular to the crankshaft (because it has secondary, tertiary and
quaternary imbalances that give it more moves than Vegas Pole-Dancer!).
There is NO way to get rid of these secondary and tertiary imbalances
passively/statically.  The only way to get rid of them is to mechanically
counteract them with specific counter-rotating balance shafts. 

The geometry of a flat opposed 6 makes it inherently devoid of any secondary
or tertiary imbalances, so it's an inherently smooth, low-stress engine.   

John