Spark Plug Guide for the 1934 Packard Model 1106
Get your Straight-Eight engine firing perfectly with the right new spark plugs.
- The correct spark plug gap for the 1934 Packard Model 1106 is 0.025 inches; always verify this before installation.
- Use a standard copper-core spark plug from a period-correct brand like Champion; avoid modern platinum or iridium plugs.
- Champion J11C (non-resistor) and RJ12C (resistor) are appropriate modern replacements.
- Due to the engine's age and design, plan to inspect spark plugs annually for fouling.
Signs of Failing Spark Plugs
An engine from 1934 gives clear signs when its spark plugs are worn. Because there are no computer controls, you must rely on what the car is telling you. Watch for these symptoms:
- Hard Starting: The engine turns over but struggles to catch and run.
- Rough Idle: The engine shakes or runs unevenly when the car is stopped.
- Engine Misfires: You may feel a stumble or hesitation from the engine, especially when accelerating.
- Reduced Power: The car feels sluggish and less responsive than usual.
- Black Soot on Plugs: Old plugs can become fouled with carbon from fuel or oil, which is a common issue in vintage engines.
Choosing the Right Aftermarket Spark Plug
For a 1934 Packard, the idea of "OEM" vs. "aftermarket" is different than for a modern car. Original Packard-supplied parts are no longer made. However, brands like Champion were original equipment suppliers for Packard and other manufacturers of the era. A new Champion spark plug is an excellent, period-correct choice for your vehicle.
The most important factors are using the correct type and heat range.
- Stick with Copper Plugs: Your Packard's ignition system was designed for standard copper-core spark plugs. Modern platinum or iridium plugs are not necessary and can sometimes lead to weaker performance because the ignition system wasn't designed for them.
- Resistor vs. Non-Resistor: If your car has a radio, resistor plugs (like a Champion RJ12C) can help prevent static. If you prioritize a raw, strong spark and have no radio, a non-resistor plug (like a Champion J11C) is also an option.
- Heat Range is Key: The heat range determines how hot the tip of the spark plug gets. Using a plug that is too "cold" can lead to carbon fouling, especially with modern fuels and gentle driving. If you frequently find your plugs are black and sooty, a slightly "hotter" plug might be needed.
New Aftermarket Spark Plug Cost
| Part | Price Range (per plug) |
|---|---|
| New Aftermarket Spark Plug (Champion) | $3.70 - $4.69 |
Prices are estimates and may vary based on the specific plug type (resistor vs. non-resistor) and retailer.
Frequently Asked Questions
What is the correct spark plug gap for my 1934 Packard?
The factory specification for the 1934 Packard eight-cylinder engine is a gap of 0.025 inches. Always check and adjust the gap on new plugs before installation, as they may not be set correctly out of the box.
Should I use anti-seize on the spark plug threads?
Yes, it is a good practice on these vintage engines with iron blocks. Applying a small amount of anti-seize compound to the plug threads helps prevent them from getting stuck in the cylinder head, making future changes much easier.
How often should I change the plugs on my Model 1106?
For a classic car, it's best to check the plugs annually. Due to factors like carburetor tuning and potential oil consumption, they can foul more quickly than in a modern car. Given their low cost, replacing them every 8,000-10,000 miles is good preventative maintenance.
Are there any recalls for my Packard's spark plugs?
No. The National Highway Traffic Safety Administration (NHTSA), which manages vehicle recalls, was formed in 1970. There are no official safety recalls for any part on a 1934 vehicle.
Technical Specifications
Recommended Spark Plug Gap: 0.025 inches. Plug Type: Standard Copper Core. Compatible Champion Plugs: J11C (Non-Resistor), RJ12C (Resistor).
We Have This Part in Stock
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.