Glow Plugs

Hotter plugs

• Advances ignition timing
• More power, especially at high RPM
• Typically used on small-block engines
• Can cause pre-ignition

Colder plugs

• Delays ignition timing
• Less power
• Typically used on big-block engines

Longer plugs

• Increases compression
• Advances ignition timing
• More power, especially at high RPM

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