Abstract: An improved control valve for use in a compression release engine retarder is disclosed. The control valve for the high pressure hydraulic fluid circuit of the retarder is arranged in series with a check valve so that the pressure drop in the circuit is taken principally across the check valve and the control valve is exposed only to the pressure of the low pressure hydraulic fluid supply system. In accrdance with another feature of the invention, the control valve is provided with a relief port which is opened in response to excess pressure in the low pressure hydraulic fluid supply to limit the quantity of hydraulic fluid introduced into the high pressure circuit and thereby prevent excess motion or "jacking" of the slave piston and its associated exhaust valve.

Abstract: Apparatus is provided to increase the retarding horsepower of a compression release engine retarder driven from the exhaust valve pushtube or the fuel injector pushtube which includes a plenum communicating with the exhaust valve slave piston and the master piston driven by a remote exhaust valve pushtube or the fuel injector pushtube. A trigger check valve is located between the master piston and exhaust valve slave piston so that the initial motion of the master piston delivers energy to the plenum. At a predetermined point in the travel of the master piston, the trigger check valve is opened by the master piston to permit the delivery of the energy stored in the plenum to the slave piston. Additional pumping capability is provided by a second master piston while a control check valve communicating with the second master piston limits the intake of hydraulic fluid into the system after working pressures have been attained to that hydraulic fluid which may leak from the system.

Abstract: Apparatus is provided to increase the retarding horsepower of a compression release engine retarder driven from the exhaust valve pushtube or the fuel injector pushtube which includes a plenum communicating with the exhaust valve slave piston and the master piston driven by a remote exhaust valve pushtube or the fuel injector pushtube. A trigger check valve is located between the master piston and exhaust valve slave piston so that the initial motion of the master piston delivers energy to the plenum. At a predetermined point in the travel of the master piston, the trigger check valve is opened by the master piston to permit the delivery of the energy stored in the plenum to the slave piston. Additional pumping capability is provided by a second master piston while a control check valve communicating with the second master piston limits the intake of hydraulic fluid into the system after working pressures have been attained to that hydraulic fluid which may leak from the system.

Abstract: Apparatus is provided to increase the retarding horsepower of a compression release engine retarder driven from the exhaust valve pushtube or the fuel injector pushtube which includes a plenum communicating with the exhaust valve slave piston and the master piston driven by a remote exhaust valve pushtube or the fuel injector pushtube. A trigger check valve is located between the master piston and exhaust valve slave piston so that the initial motion of the master piston delivers energy to the plenum. At a predetermined point in the travel of the master piston, the trigger check valve is opened by the master piston to permit the delivery of the energy stored in the plenum to the slave piston. Additional pumping capability is provided by a second master piston while a control check valve communicating with the second master piston limits the intake of hydraulic fluid into the system after working pressures have been attained to that hydraulic fluid which may leak from the system.

Abstract: An improved compression release retarder for internal combustion engines is disclosed. The improvement comprises hydro-mechanical mechanisms incorporated principally into the slave piston and adjustable stop which assures a prompt closing of the engine exhaust valve following a compression release event and provides means to advance the opening of the exhaust valve to begin the compression release event. The mechanism is automatic in that the exhaust valve opening advance mechanism alters the valve train lash to a predetermined level whenever the engine retarder is operated and the exhaust valve closing mechanism acts in response to the decrease in engine cylinder pressure during the compression release event.

Abstract: A process and apparatus are provided to increase the retarding horsepower of a compression release engine retarder driven from the exhaust valve pushtube or the fuel injector pushtube. The mechanism includes a plenum communicating with the exhaust valve slave piston and the master piston driven by a remote exhaust valve pushtube or the fuel injector pushtube. A trigger check valve is located between the master piston and exhaust valve slave piston so that the initial motion of the master piston delivers energy to the plenum. At a predetermined point in the travel of the master piston, the trigger check valve is opened by the master piston to permit the delivery of the energy stored in the plenum to the slave piston. Additional pumping capability is provided by a second master piston while a control check valve communicating with the second master piston limits the intake of hydraulic fluid into the system after working pressures have been attained to that hydraulic fluid which may leak from the system.

Abstract: A method and apparatus for controlling the intake manifold air pressure during compression release engine retarding of a turbocharged internal combustion engine are disclosed. The apparatus comprises a solenoid actuated pressure responsive means communicating with the intake manifold and electrically connected to the control circuit for the compression release retarder. In one form of the invention, intake manifold air pressure is controlled so as not to exceed a predetermined maximum pressure during compression release retarding while in another form of the invention the intake manifold air pressure may be adjusted by the operator to any level up to a predetermined maximum level. By controlling the intake manifold air pressure the magnitude of the retarding horsepower developed by the engine and the loads imposed on certain of the engine components may be controlled.

Abstract: An hydromechanical overhead is provided for a four-cycle internal combustion engine. The hydromechanical overhead includes a set of master cylinders and pistons adapted to be actuated by each of the engine exhaust and intake pushtubes, a set of slave cylinders and pistons adapted to actuate each exhaust and intake valve, a two-position three-way control valve associated with each slave cylinder, passageways interconnecting the several master and slave cylinders and control valves and electronic control means adapted to move the control valves between a first position wherein the engine operates in a four-cycle powering mode and a second position wherein the engine operates in a two-cycle retarding mode. A solenoid controlled lash adjustment mechanisn is provided for the exhaust and intake valves whereby the normal lash required for the powering mode of engine operation may automatically be increased to the substantially larger lash required for the two-cycle retarding mode of engine operation.

Abstract: Process and apparatus for the compression release retarding of a multi-cylinder four cycle internal combustion engine are provided. The process provides a compression release event and a bleeder event or a second compression releaser event for each engine cylinder during each complete engine cycle while employing only one intake valve opening per engine cycle. In accordance with one embodiment of the invention the normal motion of the exhaust valve is disabled and replaced with an opening of the exhaust valve at about the top dead center position of the engine piston following the compression stroke; maintaining the exhaust valve in the open position during the expansion stroke; partially closing the exhaust valve during the exhaust stroke; and fully closing the exhaust valve during the intake stroke.

Abstract: A process and apparatus are provided to increase the retarding horsepower of a compression release engine retarder driven from the exhaust valve pushtube or the fuel injector pushtube. The mechanism includes a plenum communicating with the exhaust valve slave piston and the master piston driven by a remote exhaust valve pushtube or the fuel injector pushtube. A trigger check valve is located between the master piston and exhaust valve slave piston so that the initial motion of the master piston delivers energy to the plenum. At a predetermined point in the travel of the master piston, the trigger check valve is opened by the master piston to permit the delivery of the energy stored in the plenum to the slave piston. Additional pumping capability is provided by a second master piston while a control check valve communicating with the second master piston limits the intake of hydraulic fluid into the system after working pressures have been attained to that hydraulic fluid which may leak from the system.