Abstract: Variable compression ratio (VCR) in reciprocating internal combustion engine must be achieved in very short time or in less than 10 degrees from TDC. To accomplish this a closed-circuit system of hydraulic cylinder pump-follower driven by End-Cam, centered on the crankshaft journal, and a hydraulic jack linked to a mechanical scissor jack. This arrangement speeds up the VCR action while reduces pressure load on the VCR mechanism and allows for higher compression ratio. The rotation of the End-Cam with respect to the hydraulic cylinder pump engages the plunger-follower with the Cam rise/lift at TDC. Then starts pumping oil to the hydraulic jack that is linked to the scissor jack and lift/push up the engine piston. Addition of an actuator to the End-Cam advances or delays VCR action. This hydraulic-mechanical system is compact is size with options for various mechanical linkages and customizable in different ways that two configurations are presented.