Keywords: Porter-Allen cylinder and valves, sectioned (New Catechism of the Steam Engine, 1904).jpg Porter-Allen engines were the first truly high-speed steam engines They combined Allen's design of balanced slide valves and trip valvegear with Fink's stationary link to adjust cut-off under the control of Porter's high-speed governor Like the Corliss they were four-valve engines with two separate admission and exhaust valves each operated and adjustable independently Porter-Allen steam engines steam engine cylinders |