Choosing the Right Spark Plugs for Your 1932 Packard Model 905
Keep your classic Twin-Six engine firing smoothly with the correct new aftermarket spark plugs.
- The 1932 Packard 905 requires 12 spark plugs, one for each cylinder of its Twin-Six engine.
- Use standard, non-resistor copper spark plugs. Modern platinum or iridium plugs are not suitable for the original ignition system.
- Symptoms of failure include rough idle, hard starting, engine misfires, and poor acceleration.
- Always check and set the spark plug gap before installation, typically around 0.025 inches for this era of engine.
Signs of Failing Spark Plugs in Your Packard
A 1932 Packard doesn't have a check engine light or complex computer codes. You have to listen to and feel what the engine is doing. Worn or fouled spark plugs can cause several noticeable problems.
- Hard Starting: If the engine takes longer than usual to start, weak spark plugs could be the cause. They struggle to create the initial spark needed for combustion.
- Rough Idle: When your car is stopped, the engine should sound steady and smooth. Failing plugs can cause misfires, leading to a rough, shaky idle you can feel in the car.
- Engine Misfires: A misfire is when a cylinder fails to ignite the fuel mixture. This can feel like a hesitation, stutter, or a jerking motion while driving. It disrupts the smooth power delivery the Twin-Six engine is known for.
- Poor Acceleration: If your Packard feels sluggish and doesn't accelerate with its usual authority, it may be due to inefficient combustion from bad plugs.
- Reduced Fuel Economy: When plugs don't fire correctly, unburned fuel is wasted, meaning you'll get fewer miles to the gallon.
Choosing the Right Aftermarket Spark Plugs
For a vintage vehicle like the 1932 Packard 905, "OEM" parts are no longer manufactured. Instead, owners rely on New Old Stock (NOS) or modern equivalents from trusted aftermarket brands. Champion was a common brand from the era and continues to make suitable spark plugs for classic cars.
The original plugs for these engines, such as the Champion C-7 or equivalent, have been discontinued. However, modern cross-references are available. It is crucial to select a non-resistor spark plug unless your ignition system has been specifically modified for them. Using resistor plugs in a system designed for non-resistor plugs can lead to a weak spark and poor performance.
Pro Tip: Always check the spark plug gap before installation. While many plugs come pre-gapped, it's essential to verify the setting. For many pre-war Packards, a gap of around 0.025 inches is a good starting point, but this can vary based on your specific engine's condition and ignition system.
| Part | Our Price Range (New Aftermarket) |
|---|---|
| Spark Plug | $3.70 - $4.69 |
Frequently Asked Questions (FAQ)
How many spark plugs does my 1932 Packard 905 need?
The Packard Model 905 has a "Twin-Six" engine, which is a V12. It requires twelve spark plugs, one for each cylinder.
Should I use resistor or non-resistor spark plugs?
For a stock 1932 Packard, you should use non-resistor spark plugs. The original ignition system was not designed for resistor plugs, which were introduced later to suppress radio interference. Using resistor plugs can result in a weaker spark and poor engine performance.
What is the correct spark plug gap?
The factory specification for similar Packard engines of the era is often around 0.025 inches. However, it's best to start there and adjust if needed. The condition of your ignition system can affect the ideal gap. A slightly wider gap (e.g., .028"-.030") might work with a strong, modern coil, but could cause hard starting with a weaker, original-style ignition.
Why can't I use modern platinum or iridium plugs?
While advanced, modern plugs are designed for high-energy electronic ignition systems. The ignition system in your 1932 Packard is much lower voltage. Standard copper-core spark plugs, like the recommended Champion equivalents, are more appropriate and provide a strong spark with the available voltage. Using a plug with the wrong heat range or design can lead to fouling or poor performance.
Technical Specifications
OEM Part Numbers: Champion C-7
Thread Size: Varies by specific original plug, common types for the era include 14mm and 7/8". Type: Non-Resistor Gap: Approx. 0.025" Brand: Champion is a period-appropriate and available choice.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.