1360 LS wrote:
Matt68 wrote:
The 123 for a mini does come with the vacuum advance, but as the doc says, just don't hook it up if you have a weber or dellorto. that is all you gotta do.
Check out:
http://www.tdcperformance.cait is Marcel's own site.
Is that only for a 123?? or is it prefered not to have a vacuum gauge linked up unless its a delorto or webber? The reason I ask is because I have 1 3/4 SU with vacuum.... or is vacuum advance different to teh gauge or is it one in the same? excuse my igorance... still very much learning about the mechicals and electrics of Mini's.
Vacuum advance is a way of advancing the ignition timing (so the spark occurs earlier, more degrees BTDC [before top dead centre]) at lower revs to burn the fuel more completely, give better economy and a smoother running.
The vacuum for this is taken from the carb throat on an SU (I think it is just after the throttle spindle/ butterfly). Webbers and delortos simply don't have a vacuum port.
With the 123 dizzy you can simply disconnect the vac advance pipe.
On mechanical advance dizzys you may need to alter the vac advance mechanism as well, as there have been instances of the vac advance getting stuck once disconnected from the vac pipe, and over advancing the ignition timing. (not good)
A vacuum gauge is an entirely different piece of gear. It is Manifold vacuum, and is taken from a port on the manifold. Usually used for an economy gauge, or diagnosing ring / head gasket / manifold gasket probs, in conjunction with a compression gauge.
This help?
)
!) I'm just this guy, ya know? I do stuff in the shop and I share it with others, free!
