- Aug 4, 2020
- Reaction score
- What vehicle(s) do you drive?
- 1959 coupe deville
Hi, new to this forum and happy to be here. Can anyone give some guidance on timing for my 59 coupe with a 390 engine. I switched from ported vacuum to manifold vacuum. I set initial timing to 5 BTC as per the book. Mechanical timing adds 20 crank degrees and it hovers around 25 degrees BTC. Seems to run fine. With vacuum advance canister hooked up it adds about 12 crank shaft degrees so it ends up at total timing of 36 degrees at about 2500 or 2800 rpm - somewhere around there. Given it’s a high compression engine (10.5:1) and it’s a big heavy car, does this sound right? I see posts all the time saying it can go up to 40 or more degrees total advance. I want to avoid detonation. Running 93 octane. Any guidance on this timing would be helpful. Thank you.