Unlike full sized car engines that use spark plugs and a distributor to fire the cylinders in the combustion cycle, glow engines rely on glow plugs.
In a Nitro engine, ignition is initiated by the application of a glow igniter. When the igniter is disconnected, the heat inside the combustion chamber keeps the glow plug filament glowing, firing the next cycle thereby keeping the engine running. Ignition timing in a glow engine is automatic. At higher RPM’s the plug becomes hotter, firing the fuel/air mixture earlier, effectively advancing the timing. At lower RPM’s the plug becomes cooler, firing the fuel/air mixture later, effectively retarding the timing. Using a hotter than normal glow plug will advance the ignition point, and using a colder than normal plug will retard the ignition point.
Since the glow plug performs so many important functions, proper plug selection, maintenance and having a good quality plug are crucial for an engine to perform properly.
Proper glow plug selection:
Proper glow plug selection depends on several factors. Fuel type, nitro methane content, weather, and altitude can drastically effect performance. Finding the best combination of nitro fuel and plug temperature for ideal driving condition is the key. This will help maximise the performance of the Nitro Star Engine. In general, the higher the the nitro percentage, the colder the plug should be. Conversely, the lower the nitro percentage, the hotter the plug should be.
HPI Power Plugs coils use a unique blend of Platinum and Rhodium metals to produce a high quality range of glow plugs that is the perfect match for HPI's range of Nitro-Star engines.
For use with a 1.5v Glow Igniter.
Recommended Power Plugs for HPI engines:
#160409 Standard Glow Plug Hot B4
#160410 Standard Glow Plug Medium B5
#160411 Standard Glow Plug Cold B6