O.S. Engine OS27003100 Cylinder Liner 70SZ-H replacement part for nitro RC engines  [OS27003100]

Cylinder liner for 70SZ-H nitro engines

This cylinder liner is an RC-scale replacement part intended for O.S. Engines 70SZ-H series nitro engines. It serves as the internal sleeve that the piston runs against and is used when rebuilding or restoring cylinder integrity during routine engine maintenance.

Designed as a direct replacement item, the liner's role is to restore proper bore condition and running clearances without changing crankcase or piston geometry. For installation, remove the head and piston assembly, extract the old liner following your engine's service practice, inspect mating surfaces and seals, then press or seat the new liner straight and square to maintain bore concentricity. Always follow the engine manufacturer's torque and sealing guidance when reassembling.

In tuning and maintenance workflows the liner is a service-level part: replacing a worn or scored liner can return compression levels and combustion stability to expected ranges, reducing the need for more invasive repairs. After installation, check piston-to-wall clearance and perform a careful break-in as per your engine care routine to confirm fit and sealing.

As a single-purpose cylinder sleeve, this liner is intended for hobbyist-level engine rebuilds and routine maintenance on 70SZ-H nitro RC engines, offering a straightforward way to restore bore condition during servicing.