Advance Curve

[rgh0]

Hi James
Assuming you will be running on Avgas with around 12.5 compression ratio you will need around 32 degrees maximum advance with it fully advanced by around 3500 to 4000 rpm. Around 12 degree static and 20 degree centrifugal advance. You need to do a little playing on the dyno to finalise what works best for your engine but this should be a good starting point.

I use bosch style distributors that were used on escorts in the 70's, you can fit Porsche 911 points in them and they work to 9000 plus rpm much better than the lucas originals -I got them from Performance Ignitions in Seaford but the guy who ran it has retired and closed the business unfortunately. He made them with new billet bodies and roller bearings and fitted the Bosch internals and cap so they are bullet proof and accurate. Your regs and historic specification sheet will dictate to some degree what can use I believe.

cheers
Rohan

[SJ Lambert]

Thanks for that advice Rohan, I wonder if the Performance Ignitions man might be prevailed upon once more for old times sake?

[SJ Lambert]

P I in Nunawading built me one using GB 720 points to your specs (above). They are putting together a set of leads for me. GT40 coil the way to go? Will be able to charge the battery regularly.

[rgh0]

Yes I use Bosch GT 40 coil. Works for me

cheers
Rohan

[billwill]

There#s a version of 123ignition which lets you define your advance curve via a USB connection to a laptop.

With a rolling road or suitable test drive location, you can play with the advance curve to optimise it.

And all the goodies are inside a distrubutor style casing.