The O.S. Speed P4 Glow Plug is a 24K gold-plated Turbo plug designed to commemorate O.S.'s 80th anniversary, for 21VZ-B V-Spec and most .18-.28 off-road racing Turbo head engines.
Tough Enough to Take the Heat.
Getting the best engine performance means choosing the right glow plug, which depends on a number of different factors – the engine type, air-fuel mix, nitro percentage, and even air temperature.
What's more, the right glow plug will change as conditions change. Keeping a range of glow plugs on hand will help you fine-tune glow heat and enjoy maximum performance under all conditions.
Generally, hot plugs provide better idle and acceleration than cold plugs. Cold plugs will produce more power but may idle more roughly and be harder to tune.
Spark plugs in gasoline engines cause ignition with a spark. In nitro engines, glow plugs cause ignition with heat.
Heat is created initially by connecting a glow starter or 1.5V battery to the plug. Once the plug comes up to heat, the battery is disconnected and the heat retained by the combustion chamber will keep the engine running. Engine timing is automatic and controlled by engine rpm. Running at higher rpm makes the plug hotter and "fire" the fuel-air mix sooner. At lower rpm, the filament cools and the plug fires less frequently.