Upgrade Thermo Insulator for O.S. 21B 40E 70C - OS23818140 by O.S. Engine  [OS23818140]

Reduce head heat transfer

This O.S. Engine OS23818140 thermo insulator is an RC accessory that sits between mating faces on O.S. 21B, 40E and 70C model engines to help manage heat movement at the head. It is designed to lower direct conduction and support steadier head temperatures during operation and adjustment.

Fitment is restricted to the model codes shown in the product name; check your engine stamping before fitting. Installation is typically straightforward using the engine's existing fasteners on most glow head assemblies; ensure mating surfaces are free from oil and are flat, and verify component clearance after assembly.

Employ the insulator as a thermal buffer when testing needle settings and prop choices to limit temperature swings, and keep monitoring head temperature during setup and service. This part is for RC-scale engines only and not applicable to full-size engines.