chevy 454 timing

The etoobox I have access to says to check the sticker under the hood.

Spark Plug Gap 0.045 Ignition Timing (deg) MT Refer to underfood label for exact setting. Ignition Timing (deg) AT Refer to underfood label for exact setting. Fuel Pump Pressure (psi) 9-13 Idle Speed (rpm) MT Refer to underfood label for exact setting. Idle Speed (rpm) AT Refer to underfood label for exact setting. Intake Valve Clearance HYD Exhaust Valve Clearance HYD

Oops! Please disregard the spec's I posted if they disagree with your underhood label.

Ben

That's always a good idea -- one assumes that it has the most vehicle specific information and quite likely the most recent as well (being the most flexible venue), and it's something official you can point to if the vehicle is subject to smog check.

If this is a computerized engine, and it probably is in a '94 unless somebody bodged a carbureted crate motor into there, you're really setting a sort of baseline timing that will be further fudged by the computer. Therefore you'lll probably also need a simple procedure (disconnecting a certain wire, maybe brown and white? one end of which is at the the distributor, or perhaps jumpering two terminals in the diagnostic connector) for telling the computer to stay on the sidelines while you do that. (Don't forget to undo this temporary change when you're done.)

I'd bet that it's something like 4 degrees before top dead center on the compression stroke, a classic pre-smog-and-computers value for a mild stock 454. (Pre-computer, this was a starting point for tuning, depending on conditions, octane, etc. Hmm, still is, though now you have a factory guess and a feedback loop doing the deed!) I would suggest getting a manual for a GM pickup or van that had the 454 engine as an option. This will also tell you the deal with the wire.

Good luck,

--Joe

--Joe