Split-Shaft LS1 Rocker Arms

Curtisbilt has invented and is now offering a new type of shaft style rocker system.  We call it the Split-Shaft.  This patented system consists of two cross shafts mated together by a tongue and groove.  In the center of the cross shaft is a 5/8th - 20 left hand internal thread.  This thread accepts a 5/8th -20 left hand externally threaded component we call the tower.  The tower features a larger base that mounts to the head casting.  Through the center of the tower is a hole that accepts the fastener that clamps the assembly to the cylinder head.  This creates a pair of rockers that are directly clamped to the cylinder head.  Since they are joined together by a tongue and groove, they are inter-locked together eliminating a guide place, yet are independently adjustable.

To adjust the valve lash of the rockers, simply place the socket (which is included in each set) on the hex, which is machined on the top of the tower.  While holding the socket with a 15mm combination wrench (which goes on the external hex on the backside of the socket) loosen the retaining bolt with a 6mm hex wrench which passes through the center of the socket.  Turn the tower to the desired valve lash and while holding the socket, tighten the retaining bolt.  Now your valve is locked down and adjusted.

By mating the tower to the cross shaft, a means of adjustment is provided without adding an adjustor cup and lock nut assembly to the backside of the rocker.  This does not add any unnecessary reciprocating weight to the system and allows our system to fit easily under the stock valve cover on an LS1 style motor.

The roller tipped rocker bodies are made from investment cast chrome moly steel.  The towers are made from heated treated 4340 steel.  The cross shafts, which ride on needle bearings, are made from heat treated 8620 steel and are ground between centers for concentricity and perpendicularity.

Any questions or comments, please contact Bill at billc@racecurtisbilt.com or 847-437-9345. Thanks.