Valve guide insert with frictional pre-broach retention feature

Abstract

A valve guide insert for lining and relining a valve guide bore in an internal combustion engine includes a one-piece, thin-walled, cylindrically-shaped metallic tube made from reformable bearing material having first and second ends and an intermediate portion. An inwardly tapered portion is disposed at the first end, wherein an end diameter of the inwardly tapered portion is less than an outer diameter of a valve guide bore, and wherein the outer diameter of the intermediate section is greater than an inner diameter of a valve guide bore. A longitudinal slit is included having a stepped portion along a length of the longitudinal slit. An interference portion is disposed proximate the second end, wherein the interference portion is configured to substantially secure the valve guide insert within a valve guide bore.

The invention claimed is: 
     
         1 . A valve guide insert for lining and relining a valve guide bore in an internal combustion engine having a valve with a valve stem, the valve guide bore being configured to support the valve stem for reciprocal motion, the valve guide insert comprising:
 a one-piece, cylindrically-shaped metallic tube made from reformable bearing material having first and second ends and an intermediate portion extending between the first and second ends;   a longitudinal slit disposed along the length of the valve guide insert;   an inwardly tapered portion disposed at the first end, wherein a first outer diameter of the inwardly tapered portion is less than an inner diameter of a valve guide bore, and wherein a second diameter of the intermediate section is greater than an inner diameter of a valve guide bore; and   an interference portion disposed proximate the second end, wherein the interference portion is configured to substantially secure the valve guide insert within a valve guide bore.   
     
     
         2 . The valve guide insert of  claim 1 , wherein the interference portion includes a narrowed portion of the longitudinal slit, and wherein the width of the slit at the narrowed portion is less than the width of the slit distal to the narrowed portion, and wherein the longitudinal slit includes a stepped portion. 
     
     
         3 . The valve guide insert of  claim 2 , wherein the narrowed portion has a substantially consistent width across the longitudinal slit. 
     
     
         4 . The valve guide insert of  claim 2 , wherein the width of the narrowed portion decreases from a first width proximate the intermediate portion to a second width distal from the intermediate portion. 
     
     
         5 . The valve guide insert of  claim 1 , wherein the interference portion includes an outwardly flared portion. 
     
     
         6 . The valve guide insert of  claim 5 , wherein the outwardly flared portion has a consistent thickness. 
     
     
         7 . The valve guide insert of  claim 1 , wherein the inwardly tapered portion has a consistent thickness. 
     
     
         8 . The valve guide insert of  claim 1 , wherein an inner surface of the valve guide insert includes a substantially spiral groove defined therein. 
     
     
         9 . A valve guide insert for lining and relining a valve guide bore in an internal combustion engine having a valve with a valve stem, and the valve guide bore being configured to support the valve stem for reciprocal motion, the valve guide insert comprising:
 a one-piece, cylindrically-shaped metallic tube made from reformable bearing material having first and second ends and an intermediate portion extending between the first and second ends;   an inwardly tapered portion disposed at the first end, wherein a first outer diameter of the inwardly tapered portion is less than an inner diameter of the valve guide bore, and wherein a second outer diameter of the intermediate portion is greater than an inner diameter of the valve guide bore;   a longitudinal slit disposed along the length of the valve guide insert, wherein the longitudinal slit includes a stepped portion; and   an interference portion disposed on at least a portion of an outer surface of the valve guide insert.   
     
     
         10 . The valve guide insert of  claim 9 , wherein the interference portion includes an integral surface condition having a roughness parameter of greater than about  32  Ra. 
     
     
         11 . The valve guide insert of  claim 10 , wherein the interference portion includes an applied grit material. 
     
     
         12 . The valve guide insert of  claim 9 , wherein the interference portion includes an adhesive compound. 
     
     
         13 . The valve guide insert of  claim 12 , wherein the adhesive compound is an anaerobic adhesive retaining compound. 
     
     
         14 . The valve guide insert of  claim 1 , wherein the interference portion includes a narrowed portion of the longitudinal slit, and wherein the width of the slit at the narrowed portion is less than the width of the slit distal to the narrowed portion. 
     
     
         15 . The valve guide insert of  claim 14 , wherein the narrowed portion has a substantially consistent width across the longitudinal slit. 
     
     
         16 . The valve guide insert of  claim 14 , wherein the width of the narrowed portion decreases from a first width proximate the intermediate portion to a second width distal from the intermediate portion. 
     
     
         17 . The valve guide insert of  claim 9 , wherein the valve guide insert includes an outwardly flared portion proximate the second end. 
     
     
         18 . The valve guide insert of  claim 9 , wherein an inner surface of the valve guide insert includes a substantially spiral groove defined therein. 
     
     
         19 . A valve guide insert for lining and relining a valve guide bore in an internal combustion engine having a valve with a valve stem, and the valve guide bore being configured to support the valve stem for reciprocal motion, the valve guide insert comprising:
 a formed cylindrical tube having a substantially consistent wall thickness, first and second ends, first and second edges that extend between the first and second ends and an intermediate portion defined within the first and second ends and the first and second edges, wherein the cylindrical tube is shaped such that the first and second edges define a longitudinal slit along a length of the cylindrical tube; and   an outwardly flared portion of the cylindrical tube is disposed proximate one of the first and second ends.   
     
     
         20 . The valve guide insert of  claim 19 , further comprising:
 an interference portion disposed proximate the intermediate portion, wherein the interference portion includes at least one of an integral surface condition and an applied adhesive compound.