Abstract: Methods and systems are described for a hybrid vehicle with a passive prechamber combustion engine. The system includes a passive prechamber combustion engine, an electric motor, and a controller communicatively coupled to the combustion engine and the electric motor. The combustion engine is configured to operate at engine loads satisfying a load threshold. The controller is configured to determine whether an engine load falls below the load threshold. The controller is configured to select the electric motor to propel the vehicle. The controller is configured to determine whether the engine load satisfies the load threshold. The controller is configured to select the combustion engine to propel the vehicle for providing efficient fuel consumption associated with prechamber ignition in response to determining that the engine load satisfies the load threshold.

Abstract: Methods and systems are described for combustion engine mode optimization. The system includes a combustion engine, a fuel delivery system, and a controller communicatively coupled to the combustion engine and the fuel delivery system. The controller selects a low temperature combustion mode based on the combustion engine being warmer than a predetermined temperature and low load conditions on the combustion engine. The low temperature combustion mode includes instructions that reduces an intake valve opening duration and an exhaust valve opening duration. The controller reduces the intake valve opening duration and the exhaust valve opening duration to create a delay between an intake valve opening duration and an exhaust valve opening duration in response to selecting the low temperature combustion mode. The delay increases a residual gas temperature in the combustion chamber and induces auto-ignition of fuel in the combustion chamber.

Abstract: A valve seal removal tool includes: an elongated, threaded rod having a stopper mounted at a proximal end of the rod and a collet connected to a distal end of the rod having an inner circumference capable of being fitted over an outer circumference of a valve seal; a collet holder movable along the longitudinal axis of the rod, and having an inner circumference capable of being fitted over an outer circumference of a proximal end of the collet; a threaded nut coupled to the rod; and a slide hammer slidable along the rod and having a proximal end that opposes the stopper and is operable to slidably contact the stopper. Tightening the nut in a distal direction of the rod causes the nut to contact the collet holder, forcing the collet holder to move over a portion of the collet which compresses the collet.