The following ignition timing recommendations are generic but will work with 90% of naturally asperated engines. Although the recommended timing may not be perfect it will be a lot closer to perfect than what most cars are running now.
Ignition timing is the redheaded stepchild..... and one of the most misunderstood functions in the internal combustion engine. To the uninformed, "hell it runs so it must be OK."
Initial timing: 15-20 degrees (vacuum advance disconnected)
Mechanical advance: 15-20 degrees all in by 2600-3000 rpm.
Total timing: 30-40 degrees all in by 2600-3000 rpm.
Vacuum advance: 5-15 degrees.(try connecting to manifold AND/OR ported vacuum to see which the engine likes best)
The above recommendations won't work with an engine with 12.5:1+ compression ratio but that engine wouldn't fall in the 90% catagory anyway. Don't be afraid to experiment...... but don't get very far outside these guidelines or you could end up with an "Ah s**t".
I hope this helps some of you out there,
Ron
