Thermal Insulator OS23818140 for O.S. 21B, 40E, 70C Engines by O.S. Engine  [OS23818140]

Engine head temperature control

This O.S. Engine OS23818140 thermo insulator is an accessory made for RC-scale O.S. 21B, 40E and 70C engines, positioned between mating surfaces to limit heat transfer at the head area. It aims to lessen direct heat conduction and promote steadier head temperature under both running and tuning conditions.

Only the model codes listed in the product name are supported; inspect your engine stamping before fitting. Installation normally uses the engine's current mounting hardware and is simple on most glow head assemblies; ensure faces are clean and flat and check for any clearance issues after refit.

During tuning it works as a thermal buffer to minimise temperature fluctuations when trialing needle positions and prop combinations. Keep monitoring head temperature as part of routine setup and maintenance. This item is intended for RC use and not for full-size engines.