Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Methods and systems are provided for tracking a fuel puddle mass in the intake port of a deactivated engine cylinder. The difference in fuel evaporation rate in the deactivated cylinder intake is accounted for by applying distinct time constant and gain values to a transient fuel compensation model. A fuel vapor content is clipped once the intake vapor pressure in the intake port of the deactivated cylinder reaches a saturation pressure limit.

Abstract: Systems and methods are provided for increasing the accuracy of air charge estimation for a cylinder that is selectively deactivatable. A controller may deactivate the cylinder in accordance with a firing pattern selected based on torque demand. An air charge estimate of the firing cylinder is then adjusted based on whether the cylinder was fired or skipped on a previous engine cycle when operating according to the selected firing pattern.

Abstract: Systems and methods are provided for increasing the accuracy of air charge estimation for a cylinder that is selectively deactivatable. A controller may deactivate the cylinder in accordance with a firing pattern selected based on torque demand. An air charge estimate of the firing cylinder is then adjusted based on whether the cylinder was fired or skipped on a previous engine cycle when operating according to the selected firing pattern.

Abstract: An adjustable connecting rod system includes a reliable, rapidly responsive mechanism for varying effective connecting rod length to vary the compression ratio of the engine. The mechanism may employ the momentum of connecting rod components during operation of the engine to provide actuation force to vary connecting rod length. Connecting rod length is preferably controlled by manipulation of fluid-actuated locking members. In a preferred embodiment, hydraulic pressure is applied through the use of engine oil or other hydraulic fluids. The connecting rod preferably employs one or more movable compression members such as roller members or other mechanical components that may be shifted from one position to another with relatively little friction in order to vary the effective length of the connecting rod. The movable compression members may engage surfaces of both the crankpin bearing retainer and the connecting rod body, loaded in compression to transmit forces therebetween.

Abstract: An adjustable connecting rod system includes a reliable, rapidly responsive mechanism for varying effective connecting rod length to vary the compression ratio of the engine. The mechanism may employ the momentum of connecting rod components during operation of the engine to provide actuation force to vary connecting rod length. Connecting rod length is preferably controlled by manipulation of fluid-actuated locking members. In a preferred embodiment, hydraulic pressure is applied through the use of engine oil or other hydraulic fluids. The connecting rod preferably employs one or more movable compression members such as roller members or other mechanical components that may be shifted from one position to another with relatively little friction in order to vary the effective length of the connecting rod. The movable compression members may engage surfaces of both the crankpin bearing retainer and the connecting rod body, loaded in compression to transmit forces therebetween.

Abstract: A crankshaft, for use with a variable compression ratio engine having a connecting rod and a rod bearing, includes a crankpin adapted to be coupled to the connecting rod with the rod bearing disposed between the crankpin and the connecting rod. The crankpin includes a circumferential surface having first and second side surface portions and a main surface portion disposed between the side surface portions. The main surface portion is configured to receive the rod bearing. The first side surface portion has a first aperture disposed at least partially outwardly of the rod bearing when the rod bearing is received on the main surface portion of the crankpin and the crankpin is coupled to the connecting rod. The crankpin further defines, at least partially, a first fluid passage for supplying pressurized fluid to the first aperture, such that the fluid is useable to vary compression ratio of the engine.

Abstract: A connecting rod assembly is provided for varying a compression ratio of an internal combustion engine having a crankshaft and a piston. The assembly includes a first portion adapted to be connected to the crankshaft and having a cylindrical aperture. The assembly further includes a second portion adapted to be connected to the piston and movable with respect to the first portion. In addition, the assembly includes a locking element having a cylindrical portion that is disposed at least partially in the cylindrical aperture. The locking element is movable between an unlocked position and a locked position for locking the second portion at a first position relative to the first portion, wherein the first position corresponds to a first compression ratio of the engine.

Abstract: A crankshaft, for use with a variable compression ratio engine having a connecting rod and a rod bearing, includes a crankpin adapted to be coupled to the connecting rod with the rod bearing disposed between the crankpin and the connecting rod. The crankpin includes a circumferential surface having first and second side surface portions and a main surface portion disposed between the side surface portions. The main surface portion is configured to receive the rod bearing. The first side surface portion has a first aperture disposed at least partially outwardly of the rod bearing when the rod bearing is received on the main surface portion of the crankpin and the crankpin is coupled to the connecting rod. The crankpin further defines, at least partially, a first fluid passage for supplying pressurized fluid to the first aperture, such that the fluid is useable to vary compression ratio of the engine.

Abstract: A connecting rod assembly is provided for varying a compression ratio of an internal combustion engine having a crankshaft and a piston. The connecting rod assembly includes a first portion adapted to be connected to the crankshaft, and a second portion adapted to be connected to the piston and movable with respect to the first portion. The connecting rod assembly further includes a locking mechanism disposed between the first and second portions. The locking mechanism includes a rotatable locking element that is configured to lock the second portion at a first position relative to the first portion. Furthermore, the first position corresponds to a first compression ratio of the engine.

Abstract: A connecting rod assembly is provided for varying a compression ratio of an internal combustion engine having a crankshaft and a piston. The assembly includes a first portion adapted to be connected to the crankshaft and having a cylindrical aperture. The assembly further includes a second portion adapted to be connected to the piston and movable with respect to the first portion. In addition, the assembly includes a locking element having a cylindrical portion that is disposed at least partially in the cylindrical aperture. The locking element is movable between an unlocked position and a locked position for locking the second portion at a first position relative to the first portion, wherein the first position corresponds to a first compression ratio of the engine.

Abstract: A connecting rod assembly is provided for varying a compression ratio of an internal combustion engine having a crankshaft and a piston. The connecting rod assembly includes a first portion adapted to be connected to the crankshaft, and a second portion adapted to be connected to the piston and movable with respect to the first portion. The connecting rod assembly further includes a locking mechanism disposed between the first and second portions. The locking mechanism includes a rotatable locking element that is configured to lock the second portion at a first position relative to the first portion. Furthermore, the first position corresponds to a first compression ratio of the engine.

Abstract: A variable length connecting rod 13 for changing a compression ratio of an engine is provided. The connecting rod 13 includes a first locking assembly 36 for locking the connecting rod 13 in a first effective length setting corresponding to a high compression ratio. The connecting rod 13 further includes a second locking assembly 38 for releasably locking the connecting rod 13 in a second effective length setting corresponding to a low compression ratio. When a length change is initiated, hydraulic fluid unlocks one of the locking assemblies 36, 38, allowing inertial force to effect the length change during an engine cycle. At completion of a length change, the other locking assembly 36, 38 automatically locks. The locking assemblies 36, 38 are self-contained units that are assembled to a bearing retainer 24.