[Fot] How to best hook up a two vacuum distributor on a 74 TR6

[Richard Good]

Jim,

The front vac unit advances the timing with vacuum and the rear one 
retards.  My preference is to connect the front unit directly to 
manifold vacuum at the banjo fitting on top of the manifold.  This gives 
it full advance at idle and light throttle and as the engine load 
increases, the vacuum drops and the timing retards to keep it from 
pinging.  Set the timing just short of pinging at any any load.  The 
throttle response should be very snappy. The only down side is a 
tendency to run on when you shut it down.  The unused vac unit may be 
left open but obviously you need to plug any unused vac ports on the carb.

Richard Good
Good Parts

jim hearn wrote:

>I have a 1974 TR6 that I use entirely for AutoX and on the track.  It was
>previously an SCCA club racer.  I have not had the motor down so the only
>mods that I am aware of are slightly hotter cam (don't know specs), headers
>(homemade but look good), and the early two vacuum distributor.  If I only
>have one vacuum line from the stock ZS carbs, does it matter which vacuum
>unit I hook it to and is the other simply closed off?  Or is there another
>way altogether?  Any thoughts or insight would be greatly appreciated.
>Thanks, Jim