[TR] Cam idle update

[Brian.L.Jones at gsk.com]

Randall wrote: 

Er, well, actually it's the other way around.  Vacuum is created by 
closing
the throttles and impeding the flow of fuel/air into the engine; at 
maximum
acceleration (throttles wide) there is very nearly no vacuum at all and
hence no vacuum advance.  So, the vacuum advance (if present, most TR6
didn't have vacuum advance) is maximum at cruise (no acceleration at all)
and is primarily a device to improve fuel economy.

You're right Randall (no surprise there!). I had it the other way around 
in my mind. 

Gary: here's a doc I couldn't find last night on tuning the distributor 
with useful info on re-curving etc.

http://www.teglerizer.com/mgstuff/lucastuning.pdf

Cheers,

Brian