* Engine modifications: Has the engine been modified? Cam upgrades, different heads, etc., all affect optimal timing.
* Fuel type: The type of fuel (regular, premium, etc.) can influence the ideal timing setting.
* Altitude: Higher altitudes require different timing settings.
* Condition of the engine: Worn components may necessitate adjustments to the timing.
The best approach:
1. Consult your owner's manual: This is the first place to look for the factory recommended timing. It will likely specify a Base Timing setting.
2. Use a timing light: You need a timing light to accurately check and adjust the timing. This involves finding the timing marks on your engine's balancer and aligning them with the pointer on the timing cover while the engine runs.
3. Look for a timing sticker: Some vehicles have a sticker on the engine that provides the recommended timing.
4. Consider a professional: If you are unsure, have a qualified mechanic check and adjust the timing. Incorrect timing can damage your engine.
General Information (Use with Caution):
While a *starting point* might be around 10 degrees BTDC (Before Top Dead Center) at idle for a stock 1986 Ford 460, this is highly unreliable without considering the factors mentioned above. The optimal timing must be determined dynamically, often through a process of adjustment and testing. This often involves a vacuum advance that adjusts timing as engine speed and load change.
In short: Don't rely on a single number. Find your owner's manual, use a timing light, and consider professional help if needed.
