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

Overview: crankcase role and compatibility

This crankcase is supplied as an RC replacement item listed under O.S. Engine OS27921000 and is specified for use with 61RX-H and HGL model codes shown in the product title. It serves as the main housing that positions the crankshaft and bearings, ensuring internal alignment is retained during rebuilds and servicing.

Compatibility applies only to the engine codes named in the product title and is intended for hobby nitro engine applications. Prior to replacing the crankcase, thoroughly clean all mating faces, check bearing seat integrity, and inspect any seals or gaskets to guarantee correct assembly and longevity.

Accurate crankcase placement supports consistent crankshaft runout and correct bearing preload, which can influence idle behavior and overall engine performance. Confirm proper fit with the crankpin and bearing sizes during trial assembly before completing the rebuild.

Provided as a direct replacement for the 61RX-H and HGL engine references, this crankcase restores internal alignment and crankshaft geometry for rebuilds and regular maintenance.