Abstract: An improved design for valve operation in internal combustion type engines which incorporate an overhead cam. This invention eliminates the valve spring. In current engines of this type an overhead cam lobe provides the force to the system to open an intake or exhaust valve and a compressed valve spring provides the stored energy to force the valve back closed. This invention uses two cam lobes on an overhead cam 15, an open cam lobe 16 and a close cam lobe 17; and two geared rockers, a open valve rocker 19 and a close valve rocker 20. A valve stem retainer assembly 12 is required to always engage the valve during operation. Positive force from the lobes of the overhead cam shaft is used to both open and close an intake or exhaust valve. The key is that only one of the cam shaft lobes drives the system at a time. If the close valve cam lobe 17 is providing the force to close the valve then the open valve cam lobe 16 is not engaged with the cam.

Abstract: An improved design for pushrod operated internal combustion type engines. This invention eliminates the valve spring altogether. In current engines of this type a cam lobe provides the positive upward force to the system to open an intake or exhaust valve and a valve spring provides the constant force to close the valve. This invention uses two cam lobes, an open cam lobe 22 and a close cam lobe 23; two pushrods, and open pushrod 24 and a close pushrod 25; and two geared rockers, a open geared rocker 26 and a close geared rocker 27. A valve stem box retainer 32 is required to pull the valve into a closed position. Positive upward force from the cam shaft is used to both open and close an intake or exhaust valve. The key is that only one of the cam shaft lobes drives the system at a time. If the close valve cam lobe 21 is providing the upward force to close the valve than the open valve cam lobe 20 is not engaged.