Ignition timing

[dukeenfield]

Hi,Is the ignition timing supposed to be set at 8 degrees before tdc (with vacuum pipe off),when using unleaded petrol with lead replacement stuff in,or is that wrong.

[dukeenfield]

Sorry I forgot to say what model its on,its a 1986 350i.

[ssc1]

i tried it at 8 degrees but found that it pinked alot even with opitimax fuel so i set it at 5 degrees and it ran better and i think i fitted ngk bp7 type plugs but some say that it should have bp6es type to reduce pinking , never had that problem with the chimeara's though , so it must be an odd wedge thing. did you get the steve heath bible for the wedge as that helps alot..

[350zwelgje]

8 degrees is fine for me, but using 98 RON unleaded fuel.
If you want to try 95 RON, 5 degrees it is.
But it only starts here, because it depends on the state and tune of your engine.
Subject has been discussed before, try a search as well.

Rob

[dukeenfield]

Thanks for your help every body,yes I have got Steve Heath book now

[Boosted LS1]

Make sure you plug the vacuum pipe when you set the timing. You may find that your engine likes some extra advance, I've run up to 14 degrees on some engines which gave excellent throttle response low down. I did have to get rid of pinking further up the rev range though (had a mallory at the time so could adjust it).

[jim simkins]

I have played with timing on my 84 350
and found 4 degrees to be the best setting
set using strobe light with vacum pipe connected
and running on super unleaded

[Boosted LS1]

jim simkins said:

I have played with timing on my 84 350 and found 4 degrees to be the best setting set using strobe light with vacum pipe connected and running on super unleaded

Think you're meant to disconnect the vacuum pipe though and plug the hose so as to leave things mechanical.