... Frame: One piece, cast iron heavily ribbed casting with tie bolt construction. Aluminum top cover and end covers;Crosshead: one piece ... main and connecting rod bearings, held in place by 4-bolt;Connecting rod: Closed die forged SAE1045 steel, heat treated, ... piston, piston rod, and cylinder, to meet the requirements of heavy duty, high speed operation.Maximum RPM, 1200 rpm, Maximum discharge pressure ...