* Year of the car: Nova's spanned many years, and engine specifications changed. The timing will be different for a 1968 Nova than a 1978 Nova.
* Engine specifics: Even within a given year, the specific engine configuration (e.g., carburetor vs. fuel injection, camshaft type, compression ratio) will affect optimal timing.
* Fuel type: The type of gasoline used can slightly alter ideal timing.
Where to find the correct timing:
1. Owner's Manual: The best source is the owner's manual for your specific year and model Nova. It will specify the recommended timing.
2. Decal Under the Hood: Many cars have a sticker under the hood specifying the factory recommended timing.
3. Repair Manual: A repair manual specific to your year and engine will provide the information.
4. Chevrolet Service Information: Chevrolet's own service information (often found online through subscription services) is a definitive source.
General Guidelines (but not a substitute for the above):
Generally, you're looking at a range of initial timing settings around 8-12 degrees BTDC (Before Top Dead Center) at idle. However, this is only a starting point and must be further adjusted using a timing light and following the procedure outlined in your repair manual. The final timing will likely be higher (e.g., 15-25 degrees BTDC) at higher RPM, as indicated by the advance curve of the distributor. Improper timing can significantly impact performance, fuel economy, and engine longevity.
