The SA646277 hydraulic lifter is an aircraft engine valve train component used in Continental-compatible piston engines. It is installed in the engine case and operates against the camshaft to actuate the exhaust valve via pushrods and rocker arms.

It uses engine oil pressure to automatically maintain zero valve lash, compensating for thermal expansion and wear in the valve train. This improves valve timing stability, reduces noise, and minimizes maintenance adjustment requirements.

Key features include:

PMA hydraulic lifter (exhaust valve application)
Maintains automatic valve lash adjustment using oil pressure
Precision-machined steel body with internal hydraulic mechanism
Camshaft contact surface designed for continuous rotation
Reduces valve train noise and wear
Improves valve timing consistency during engine operation
Designed for high-RPM, high-temperature aviation engine environments
Lubricated through engine oil system
Compatible with Continental piston engine configurations (model-dependent IPC use)
Used in camshaft/valve train assemblies during overhaul and maintenance