O.S. Engine OS22514000 Heatsink Head 25AX Cylinder Head  [OS22514000]

Heatsink head for 25AX engines

This heatsink head is an RC-scale cylinder head replacement intended for the O.S. Engine 25AX family as indicated by the product name. Its finned heatsink profile helps move heat away from the combustion area, supporting more consistent operating temperature during running and tuning sessions.

Installation is straightforward for experienced RC engine users: remove the stock head, confirm the mating surfaces are clean and free of debris, reuse or replace any head gasket as appropriate, and tighten the head evenly to ensure proper sealing. Avoid overtightening and verify that the head sits flat before final assembly.

On tuning and maintenance, the heatsink head’s role is passive but important: by improving heat dispersion it can reduce thermal drift when adjusting needle valves or setting high-RPM runs, making temperature-related performance shifts easier to manage. Regular inspection of the head and surrounding sealing surfaces will maintain consistency.