* Engine condition: A well-maintained engine might run best at a slightly different timing than one that's worn.
* Cam shaft: Different camshafts will require different timing. A stock cam will have a different optimal timing than a performance cam.
* Altitude: Higher altitudes require slightly retarded timing.
* Fuel type: The octane rating of your fuel will influence the timing.
Instead of a specific number, the best approach is to find the recommended range in your owner's manual or a factory service manual for that specific engine. These manuals will usually give a range, for example, something like 4-6 degrees BTDC (Before Top Dead Center) at idle.
To find the correct timing:
1. Consult your owner's manual or a factory service manual: This is the most reliable source of information.
2. Use a timing light: This is essential for setting your ignition timing accurately. You will need to connect the timing light to the number 1 spark plug wire and align the timing mark on the crankshaft pulley with the timing pointer on the engine block while the engine is running.
3. Adjust the distributor: The distributor is usually adjusted with a small screw or clamp to advance or retard the timing. Make small adjustments and check the timing after each adjustment.
4. Check your vacuum advance: The vacuum advance on the distributor should be functioning correctly; a malfunctioning vacuum advance can make accurate timing impossible.
Without access to your specific vehicle's documentation, providing a specific number is unreliable and could potentially damage your engine. Always consult your owner's manual or a reputable repair manual for your specific 1964 Chevy 283 2bbl engine.
