Headsink Cylinder Head Upgrade for 91SZ-H.RZ-H - OS29064000 O.S. Engine  [OS29064000]

Cooling-focused headsink for 91-series engines

This headsink cylinder head is a like-for-like replacement identified by the OS29064000 model number and intended for the 91SZ-H.RZ-H family of RC nitro engines. It provides a renewed external cooling face while leaving bore and internal components unchanged.

Installation follows standard nitro engine practice: remove the existing head, clean all gasket residues and mounting surfaces, fit the headsink head squarely, and tighten bolts to the torque recommended by the engine maker. Do not over-torque and check sealing and clearance before running the engine.

Used primarily as a maintenance or service item, the headsink head helps maintain predictable heat transfer and ensures a proper mating surface for glow head and gasket setup. Verify the 91SZ-H.RZ-H compatibility mark on your engine before ordering.

Opt for this head when you need a straightforward headsink replacement for engines marked 91SZ-H.RZ-H and adhere to normal maintenance and tuning checks.