[TR] Distributor help

[Randall]

> I had the vacuum advance go out on my TR4a many years ago, I 
> could tell something was wrong,

I agree it makes a difference, but it is fairly subtle.  If you've never driven the car with a working VA, you might not notice
there was anything wrong.  And since it is only active at part throttle, it has no impact on maximum power or 0-60 time.  In fact,
it was deleted on later US-spec TR6 (from about 1972).

> you 
> could probably adjust the static advance to offset this 
> somewhat,

Not a good idea, IMO.  The reason the vacuum advance only works at part throttle is because it compensates for slower flame speeds
when the cylinder pressure is lower.  If you change the initial advance, that also affects full throttle operation, where pressures
are higher and you are more likely to get detonation.  Detonation can destroy an engine in a hurry, and isn't always audible.  BTDT,
got the broken piston.

-- Randall