O.S. Engine OS27921000 Crankcase for 61RX-H,HGL Engine Replacement Part  [OS27921000]

Crankcase details and fitment

This crankcase is an RC-scale replacement part listed as O.S. Engine OS27921000 and specified for use with the 61RX-H and HGL engine designations referenced in the product name. It is intended to serve as the outer housing that locates the crankshaft and bearings, preserving internal alignment during rebuilds and routine maintenance.

Compatibility is limited to the model codes shown in the product name, and the part is intended for hobby-grade RC nitro engine applications only. When preparing an engine for crankcase replacement, clean the mating surfaces, verify bearing seats, and inspect internal seals and gaskets before final assembly to maintain reliable crankshaft alignment.

For tuning and setup, a correctly seated crankcase helps ensure consistent crankshaft runout and bearing preload, which can affect idle stability and power delivery in RC engines. This component replaces the existing crankcase housing and should be checked for proper fit with your engine’s crankpin and bearing sizes during installation.

This crankcase is supplied as a direct replacement housing for the 61RX-H and HGL engine references, serving the role of restoring crankshaft alignment and internal geometry during engine rebuilds and maintenance procedures.