Discussion Starter · #1 ·
I've read Lars' article on timing, and several other posts on this site and others, but I am still partially confused about adding vacuum advance. I will be using a full manifold port, with no pcv valve, and a 1116163 (ms 163 16) vacuum advance canister on a stock 1970 396/350 motor and points distributor. My question is, when I set the initial timing without the vacuum advance do I need to back off that timing when I add the vacuum back in? My reason for asking is that If my initial/base timing is 12* and my vacuum advance gives 16* fully deployed, then I would have to retard the timing to 4* BTDC to still have the 12* of initial, which seems way too low; on the other hand if I add the 16* of vac. adv. onto the 12* initial, then I would have 28* at idle, which seems too high.