RE: stag-digest V3 #7

[Mike Wattam <101714.1343@domain.elided>]

Dear Brian

USA spec cars had extensive 'emmissions' requirements, which included very
tight control of the timing to ensure clean combustion - or at least that
was the theory, they failed to take into account sloppy distributors!

So, the vacuum pipe to the distributor passed through a heat-sensing valve
on the radiator header tank, thus varyingthe vacuum advance depending on
the engine temperature.  Then the pipe went through what isactually a very
crude fuel trap, to eliminate it coming out to atmosphere if the vacuum
diaphragm split.

The whole theory and practice is tenuous, I would certainly junk it if I
came across it on a Stag.  If your car doen't have this, somebody got there
before me!

Hope this helps

Mike