[Fot] Dual- row timing gear for small-crank Spitfire?

[Randall]

> The chain isn't considered as 
> part of the rotating mass since it's an independent member which both 
> slides and rotates on its own (at a much lower rate than 
> either crank or 
> cam),

I disagree.  Because the crank gear is connected to the chain, it takes the
same amount of energy to accelerate the chain as it would if the chain's
entire mass were concentrated around the rim of the gear.  The cam gear will
also add more rotational inertia than the crank gear does; even though it
turns 1/2 speed, it has twice the radius and roughly twice the mass.  Since
both speed and radius are squared in the inertia calculation (and hence
cancel out), we're still looking at roughly twice as much inertia.

Still not very much, but the effect is there.  However, I agree
whole-heartedly with not fixing what ain't broke.

Randall