What is the timing order for a 350?
The timing order, or firing order, for the Chevrolet 350 small-block V8 is 1-8-4-3-6-5-7-2, with the distributor rotor typically turning counterclockwise. This sequence dictates the order in which spark plugs fire as the crankshaft rotates and is the basis for wiring the ignition system correctly.
What the firing order means for a 350
The term “timing order” refers to the sequence in which cylinders ignite. On a Chevy 350, this fixed sequence ensures the engine runs smoothly and efficiently. Correct wire placement based on this order is essential for starting reliability and optimal idle and performance. If you’re working on a non-factory variant or an aftermarket build, verify the firing order in the specific manual for that engine.
Firing order for a Chevrolet 350
The following sequence lists the cylinders in the order they fire during engine operation. This is the standard firing order used by most Chevrolet 350 small-block engines.
- 1
- 8
- 4
- 3
- 6
- 5
- 7
- 2
Keep in mind that some aftermarket or specialized builds may deviate from this pattern. Always confirm against your engine’s service manual if you’re unsure.
How to wire the spark plugs in the correct order
Before wiring, identify the cylinder numbering on your engine and orient the distributor so the rotor points toward the first cylinder in the firing order. The wires should follow the firing sequence around the distributor cap, ensuring each spark plug receives power in the correct order.
- Identify the location of cylinder #1 and align the rotor toward it when the timing mark is at TDC on cylinder 1.
- Place the spark plug wires in the firing order 1-8-4-3-6-5-7-2 from the distributor cap to the corresponding spark plugs.
- Connect each wire firmly to its spark plug boot and ensure the correct boot orientation for each cylinder.
- Double-check the entire layout against a trusted wiring diagram for your specific year/model to avoid cross-firing.
After wiring, verify timing with a timing light and adjust idle timing per the factory specification. If you’re setting timing manually, disconnect vacuum lines if needed to prevent the advance from affecting the reading.
Verification and troubleshooting
To ensure the firing order is correct and the engine runs smoothly, use a timing light to check the idle timing and total advance. Misfires or rough running often indicate misrouted wires, incorrect cylinder numbering, or a misaligned distributor. If problems persist, consult the vehicle’s service manual for the exact specifications for your year and model.
Summary
The Chevy 350’s standard timing order is 1-8-4-3-6-5-7-2, with the distributor rotor typically rotating counterclockwise. Wire the spark plugs accordingly, verify with a timing light, and consult the exact manual for any variant or aftermarket engine. Proper timing setup yields smooth idle, good torque, and reliable starting.
