CHRYSLER 318 FIRING ORDER: 1-8-4-3-6-5-7-2 (FULL DETAIL + ANIMATION)
⚙️ 2. Why Is The Firing Order Critical For The 318 Engine?
The 1-8-4-3-6-5-7-2 sequence is not random — it was engineered by Chrysler to minimize torsional vibrations that would otherwise damage the crankshaft and main bearings. An incorrect firing order creates unbalanced firing impulses, leading to rough idle, misfires, backfires, and potentially bent pushrods or broken pistons. Moreover, the correct order ensures the carburetor or EFI system receives consistent vacuum pulses for proper air-fuel mixture.
Why do mechanics emphasize it? Because the 318 is a durable, long-stroke engine; maintaining the OEM firing order guarantees peak torque (around 250-300 lb-ft) and longevity up to 300,000 miles when maintained.
📚 3. Types Of Firing Orders (V8 Comparison)
Different V8 families use distinct firing orders based on crankshaft design. Below is a comparison table:
| Engine Family | Firing Order | Distributor Rotation |
|---|---|---|
| Chrysler 318/360 (LA/Magnum) | 1-8-4-3-6-5-7-2 | Clockwise |
| Chevrolet Small Block (traditional) | 1-8-4-3-6-5-7-2 | Counter-clockwise |
| Ford 302/351W | 1-3-7-2-6-5-4-8 | Counter-clockwise |
| LS (Gen III/IV) | 1-8-7-2-6-5-4-3 | Coil-near-plug (no distributor) |
Though the 318 shares the same numeric pattern as early Chevy, the distributor rotation (clockwise vs counter-clockwise) is opposite, causing wire routing differences.
🔢 4. Cylinder Numbering & Distributor Layout
Left bank (driver side): 1 (front) – 3 – 5 – 7 (rear)
Right bank (passenger side): 2 (front) – 4 – 6 – 8 (rear)
Distributor rotates clockwise. The #1 terminal on the cap should align with the rotor when engine is at TDC compression #1. Then, connect spark plug wires in the firing order moving clockwise around the distributor cap. Mopar distributors often have a marked “1” on the cap.
🎬 Live Animation: 318 Firing Sequence (1-8-4-3-6-5-7-2)
Watch the cylinders light up in real-time according to the correct firing order. Visual tool for mechanics, students, and enthusiasts.
Order: 1 → 8 → 4 → 3 → 6 → 5 → 7 → 2 (repeats) | Clockwise rotation
🛠️ 5. How To Set The 318 Firing Order (Step-by-Step)
- Disable ignition & remove #1 spark plug. Rotate engine clockwise (using breaker bar on crankshaft bolt) until you feel compression from #1 cylinder.
- Align timing marks to 0° TDC. The harmonic balancer mark should align with “0” on the timing tab.
- Verify distributor rotor points to #1 tower. If it points 180° off, rotate engine one full turn and re-check.
- Install distributor cap & identify #1 terminal. Then connect spark plug wires in firing order 1-8-4-3-6-5-7-2 moving clockwise around the cap.
- Double-check each cylinder wire. Ensure #1 wire goes to cylinder #1 (front-left), #8 to rear-right, #4 to second on right, etc.
- Start engine, set ignition timing with a timing light (typically 8-12° BTDC for LA 318).
Pro tip: Use a permanent marker to label each wire before removal. After setting, use a timing light to confirm no cross-fire.
🛡️ 6. Is It Safe To Alter The Firing Order On A 318?
Generally, no. The factory firing order is deeply integrated with the camshaft lobe phasing, crankshaft counterweights, and intake manifold design. Changing the firing order without a custom camshaft results in violent backfires, bent pushrods, and potentially broken pistons. However, some performance aftermarket camshafts (e.g., “4-7 swap” cams) intentionally alter the order for racing. Unless you are building a dedicated drag engine, always stick to the original 1-8-4-3-6-5-7-2 order for safety and reliability.
✅ 7. Advantages & ⚠️ Disadvantages of the 318 Firing Order
- Exceptional crankshaft balance at low/mid RPM
- Reduces torsional vibration (increases bearing life)
- Smooth idle and predictable torque curve
- Excellent for trucks, muscle cars, marine use
- Easy to diagnose due to widespread documentation
- Less efficient at very high RPM compared to flat-plane orders
- Can confuse beginners due to non-sequential numbering
- Distributor phasing critical (mistakes common)
- Not optimal for forced induction without timing retard
🚗 8. Real-World Use: Where The 318 Firing Order Matters
The Chrysler 318 has powered countless vehicles: Dodge D/W series trucks, Plymouth Barracuda, Dodge Charger (early ’70s), Jeep Grand Cherokee ZJ (5.2L Magnum), Dodge Ram 1500, and even industrial generators. In each application, the precise firing order ensures consistent torque for towing, off-road crawling, or highway cruising. Race restorers must respect the order when installing aftermarket EFI or performance distributors like MSD or Mallory.
📐 9. Deep Dive: Crankshaft Physics Behind 1-8-4-3-6-5-7-2
The 318 uses a cross-plane crankshaft with crankpins at 90° intervals. The firing order alternates between cylinder banks to create evenly spaced firing impulses every 90° of rotation. The specific pattern 1-8-4-3-6-5-7-2 ensures that no two consecutive firings happen on the same bank, minimizing rocking couple. Additionally, the sequence reduces the peak torque applied to the crankshaft snout, enhancing durability. Engineers at Chrysler validated this order with extensive stress analysis, making it the gold standard for small-block Mopar engines.
❓ 10. Frequently Asked Questions (Advanced FAQ)
Both LA and Magnum share the same firing order: 1-8-4-3-6-5-7-2. The only difference is ignition system (distributor vs coil pack on later Magnum but same sequence).
Symptoms: engine cranks but won’t start, backfires through carburetor, exhaust pops, rough idle with shaking, or no vacuum advance. Use a timing light and verify wire order.
Yes, the older 318 Poly (1957–1966) also uses the same firing order 1-8-4-3-6-5-7-2. Cylinder numbering identical.
Physically yes, but ensure the distributor gear matches (cast iron vs bronze). Firing order remains the same. Always confirm rotation (clockwise).
The 4-7 swap changes order to 1-8-7-3-6-5-4-2 for reduced crankshaft stress at high RPM. It requires a special camshaft; not recommended for stock 318 builds.
Warm up engine, connect inductive timing light to #1 plug wire, aim at harmonic balancer marks. For LA 318, set 10° BTDC at idle (vacuum advance disconnected).
Clockwise (viewed from top). This is critical for correct wire routing.
