Spark Plugs in Alternative Fuel Engines: Challenges and Innovations

Hydrogen, CNG, and biofuels demand specialized spark plug designs to address unique combustion properties.

1. Hydrogen Engines

• High flame speed (≈3× gasoline) requires smaller gaps and iridium electrodes to prevent blowout.

• Pre-ignition risks due to low ignition energy (0.02 mJ vs. gasoline’s 0.3 mJ).

2. CNG Applications

• Cold plugs combat carbon fouling from lean mixtures; reinforced insulators resist thermal shock.

3. Ethanol Flex-Fuel

• Corrosion-resistant coatings (e.g., nickel-chromium) counter acidic byproducts.

• Increased gap width to stabilize combustion in E85 blends.

4. Methanol Racing

• Platinum-tipped plugs for erosion resistance in high-MAP environments.

5. Future Trends

• Multi-electrode designs for dual-fuel engines and adaptive gap systems.

  
  

Conclusion
Alternative fuels necessitate material and geometric adaptations to maintain ignition reliability.