Optimize the Ignition Timing

[Jazzman]

Gents,

I have the feeling my distributor (a Delco D200) is fairly worn. I bought a timing light and adjusted the timing when idling yesterday night (circa 800rpm). The car runs well but I was wondering if it is worth adjusting it at 2000rpm rather than 800rpm.

The problem is that I do not know if the advance should remain the same at 2000-2500rpm. I use around 8 degrees BTDC due to fuel (6degrees BTDC in theory)

Can you advice?

[GT6Craig]

Idle at 800? your lucky! I'd say leave it, if it idles well then messing with it might just cause it to run rubbish. And thats from experiance  :o
As for the worn dizzy - might be the case, i think somebody on here told me what to do when measuring the advance. As you increase engine speed - the timing is advanced via the vacuum advance on the distributor. By making a note of the timing (use your strobe) at 1000, 2000, 3000, etc you can gain values and then compare them to factory. Which i think you can find below if you scroll down to 6 cylinder Delco models

http://www.teglerizer.com/mgstuff/advance_curves.htm

hope that points you in the right direction - its something im learning at the moment too...

[monty69]

184 wrote:

Idle at 800? your lucky! I'd say leave it, if it idles well then messing with it might just cause it to run rubbish. And thats from experiance  :o
As for the worn dizzy - might be the case, i think somebody on here told me what to do when measuring the advance. As you increase engine speed - the timing is advanced via the vacuum advance on the distributor. By making a note of the timing (use your strobe) at 1000, 2000, 3000, etc you can gain values and then compare them to factory. Which i think you can find below if you scroll down to 6 cylinder Delco models

http://www.teglerizer.com/mgstuff/advance_curves.htm

hope that points you in the right direction - its something im learning at the moment too...

advanced via the vacuum advance on the distributor.

That retards the timing!

The weights in the dissy provide the advance

The advance measurements are made with the advance and retard pipe disconnected

[CharlieB]

409 wrote:

advanced via the vacuum advance on the distributor.
That retards the timing!

No, the vacuum advance advances the ignition at light throttle (at least in Europe, I think some US cars had vacuum retard?)
Agree with the rest of your comments.