I never heard that V8 engines couldn't be fully balanced, Neil. If so,
they certainly are smooth-running, as a rule.
Another consideration occurs to me when discussing running a
four-cylinder engine on only two cylinders(or a V8 on seven cylinders as
is sometimes mentioned). I recently read a paper on the design of WWII
V12 aircraft engine crankshafts, which pointed out that the even firing
of each cylinder in normal running has a LOT to do with the stresses and
fatigue life of those cranks. If one cylinder or more is deleted, it
was found that the normal flexing and twisting of the crank was affected
very severely. And this could lead to crank failure. So aircraft
engine designers considered the various firing orders possible in a
V12(some were more favorable for crank stress than others) and crank
design in light of the fact that the engine might have to run at near
full power for long periods under combat conditions, with a cylinder or
two out, to get a damaged plane home. BH
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