Thread: V8 Ignition timing

IMHO it should be fine at 8degrees and maybe even further up at 10 or maybe even 12.
If an auto it may stall when going into reverse from park if too much advance.

These 3.9s are "rest of world" and designed to run on very low octane , maybe 88, so with 91 they can take a lot more advance.

Another reason they specify 1-2 degrees is that this cuts Nox so meets emission requirements.
Regards Philip A

i'm running around 12 on my 3.9, if your on 8-10 and not pinging under load then you should be right.

They run well on 10 degrees regardless of fuel, petrol only or gas. Remember to check your vacuum and mechanical advances are working properly, loss of either will ruin your economy.

Got mine set on 10 btdc runs great on petrol made a huge difference on gas

Thanks everyone for the replies it all confirms what I was thinking.I will be doing a run up the coast this weekend so I will see how it goes then look at sneaking it up a few more degrees.
I replaced the vac advance when I first got the car as it was shagged so everything is fine in that area.What I did notice when I had the timing light on it the other day is that the mechanical advance seems to advance o.k as per the manual however it is a bit unstable i.e jumps around a few degrees when held at say 2000rpm.I am not sure if this is normal or a symptom of some wear or stretched springs in the mechanical advance setup in the distributor.
Anyway its certainly performing a lot better than before , thanks again for the responses.