Vacuum advance question

[chris52]

My vacuum advance does not work in fact it will have never worked as the nipple on the plenum is not drilled all the way through so it has never had any suction. Would I benefit from sorting this out? the car runs well but is a little heavy on fuel compared to the last Griff I had.
The mechanical advance works fine and have set the timming at 8 deg BTDC on Idle. If it is best leaving the vacuum advance alone would I be better advancing the timing a little further to allow for the lack of vacuum advance.

Cheers Chris

[330p4]

Ghris one of our local members found this on his Griff he deilled it out & it ran better
Ian

[TVR Beaver]

Chris.. I was told you don't need it.. but I've tried my car both ways and I prefer it on... sharper at the bottom end... but make sure you drill it in the right place.. I moved mine.. it was too far back (towards the engine) so was seeing vaccume on tickover nearly... It wants to be on top of the butterfly at 2000rpm...
There are a number of ways of doing this.. get someone to hold it at 2K whilst you measure it (the butterfly)but realy needs to be under load on the flat to get it accurate...
Or the way I did... get a pot reading at 2 K whilst going down the road with wires into the Pot connector and a volt meter in the passanger seat.. then bring it back and open the butterfly until you get the same reading.. then measure and drill (try running the engine whilst you do this as it may change the reading)...
or.. you can guess it.. obout 1.5 / 2mm in front of the butterfly when at rest...
Have fun.. cheers... John