Mechanical lash adjuster for overhead cam engines

Claim 2

A mechanical lash adjuster for replacing a hydraulic lash adjuster in an internal combustion engine having an overhead cam, a rocker arm forming a socket, and a lash adjuster mounted in a smooth surfaced cylindrical opening formed in the cylinder head of the engine supporting said rocker arm at said socket, said replacement mechanical lash adjuster comprising: a free-fitting insert axially slideable into and freely rotatable in said cylinder head opening, said insert having a threaded opening therein; a screw member threadably received in said insert, said screw member having means at one end thereof for supporting said rocker arm; said insert and said screw member forming cooperative adjustment means for varying the effective length of said lash adjuster to take up slack in the valve train of said engine; and locking means for said insert to prevent rotation of said insert during adjustment of the valve lash.

Claim 3

The lash adjuster as defined in claim 1 and further including self-locking thread means on one of said screw and said insert.

Claim 4

The apparatus as defined in claim 1 wherein said insert has a flat area on an outer peripheral surface thereof and said locking means includes means secured to said cylinder head abutting said flat area to prevent rotation of said insert in said cylinder opening.

Claim 5

In the conversion of a stock overhead cam internal combustion engine having hydraulic lash adjustment means positioned in a smooth surfaced cylindrical recess in the cylinder head of said engine to a high-performance engine, the improvement comprising: replacing said hydraulic lash adjuster with a mechanical adjuster having a sleeve adapted for insertion in said recess and a screw member extending from said sleeve for supporting said rocker arm, said sleeve being axially slideable and freely rotatable in said recess; adjusting the effective length of said screw with respect to said sleeve to take up slack in the valve train of said engine; and locking means for said sleeve to prevent rotation of said insert during adjustment of the effective length of said screw with respect to said sleeve.

Claim 6

In the conversion of a stock overhead cam internal combustion engine having hydraulic lash adjustment means positioned in a smooth surfaced cylindrical recess in the cylinder head of said engine to a high-performance engine, the improvement comprising: replacing said hydraulic lash adjuster with a mechanical adjuster having a sleeve adapted for insertion in said recess and a screw member extending from said sleeve for supporting said rocker arm, said sleeve being axially slideable and freely rotatable in said recess; adjusting the effective length of said screw with respect to said sleeve to take up slack in the valve train of said engine; and locking means for said sleeve to prevent rotation of said insert during adjustment of the effective length of said screw with respect to said sleeve.

Claim 7

Apparatus for the conversion of an overhead cAm internal combustion engine having hydraulic lash adjustment means positioned in a smooth surfaced cylindrical recess in the cylinder head of said engine to an engine having mechanical lash adjustment means for taking up slack in the valve train of the engine, said engine having a rocker arm pivotally mounted for movement by said overhead cam, said apparatus comprising: an internally threaded insert member adapted for positioning in said recess formed in the cylinder head of the engine, said insert member being axially slideable and freely rotatable in said recess; a threaded screw member received in said insert, said screw member having means at one end thereof pivotally supporting said rocker arm, wherein relative movement between said screw member and said insert member varies the effective length of said lash adjuster to thereby take up the slack in the valve train of said engine; and locking means for said insert member to prevent rotation of said insert during adjustment of the valve lash.

Claim 8

Apparatus for the conversion of an overhead cAm internal combustion engine having hydraulic lash adjustment means positioned in a smooth surfaced cylindrical recess in the cylinder head of said engine to an engine having mechanical lash adjustment means for taking up slack in the valve train of the engine, said engine having a rocker arm pivotally mounted for movement by said overhead cam, said apparatus comprising: an internally threaded insert member adapted for positioning in said recess formed in the cylinder head of the engine, said insert member being axially slideable and freely rotatable in said recess; a threaded screw member received in said insert, said screw member having means at one end thereof pivotally supporting said rocker arm, wherein relative movement between said screw member and said insert member varies the effective length of said lash adjuster to thereby take up the slack in the valve train of said engine; and locking means for said insert member to prevent rotation of said insert during adjustment of the valve lash.