* Engine modifications: Has the engine been modified in any way? Modifications like different camshafts, heads, or carburetors will significantly alter the ideal timing.
* Engine condition: Worn components can affect timing needs.
* Vacuum advance: This is a crucial component of the ignition system. The vacuum advance mechanism itself needs to be functional, and the amount of advance it provides is part of the overall timing.
Therefore, you cannot simply look up a number.
To find the correct ignition timing for *your* specific 1970 Lincoln Continental 460:
1. Consult your owner's manual: This is the best place to start. It should specify the base timing (often at idle) and describe how to check and adjust the timing. If you don't have the manual, you can often find a digital copy online.
2. Check the distributor: Look for markings on the distributor itself – it might have a timing specification stamped on it.
3. Use a timing light: This is the only reliable way to measure the actual ignition timing. The process involves connecting the timing light to the spark plug wire and using the timing marks on the harmonic balancer (or crankshaft pulley) to determine the timing in degrees before top dead center (BTDC). You'll need a helper to start and run the engine while you observe the light. Many automotive repair manuals detail this procedure with illustrations.
Warning: Incorrect ignition timing can damage your engine. If you're not comfortable working on your car's ignition system, it's best to take it to a qualified mechanic.
