Desmodromic valve system and retrofit kit for conventional pushrod engines including replaceable cam lobes for adjusting lift and duration and hydraulic lifters for increased reliability

A desmodromic valve and cam system adapted to be installed into an internal combustion pushrod engine comprising an engine block and at least one head which utilizes at least one intake and one exhaust valve per cylinder, the system comprising:

• a main camshaft assembly adapted to be received within a plurality of journals disposed internally within the engine block, the camshaft assembly including a cam lobe assigned to each valve, each cam lobe adapted to be removably installed onto a main camshaft, each cam lobe defined by a pair of opposing sides, perimeter edge, mounting hole disposed through the opposing sides in a normal orientation, and follower groove formed in at least one side of the cam lobe which is representative of a desired lift and duration performance characteristic;
• a valve connector assembly installed onto a distal tip of each respective valve;
• a rocker defined by a valve movement end and a pushrod connecting end, the valve movement end adapted to be mechanically linked to a respective valve connector assembly such that the rocker can either push down or pull up a respective valve and the pushrod connecting end adapted to be mechanically linked to an upper distal end of a pushrod such that the rocker can either push down or pull up a respective pushrod;
• a hydraulic lifter follower assembly assigned to each valve which is adapted to be received within a lifter seat disposed within the engine block, each lifter assembly having a connecting means disposed on a distal end thereof which is adapted to engage and track a respective follower groove on a respective cam lobe;
• and
• a pushrod assigned to each valve, each pushrod having an upper and lower distal end, the upper distal end mechanically linked to the pushrod connecting end of a respective rocker and the lower distal end mechanically linked to a respective hydraulic follower lifter;
• wherein when the main camshaft assembly rotates, the cam lobes impart reciprocal motion to the hydraulic lifters, which impart reciprocal motion to the pushrods, which impart a rocking motion to the valve movement end of the rocker, which results in each valve being reciprocally moved upwards to a closed position or downwards to an open position as a function of each cam lobe's lift and duration without the need to use valve springs to return the valves to a closed position.