Patent ID: 6149073
Filing Date: 2000-11-21
Classification: F02M,F04B,F05C

Abstract:
A scuff and wear-resistant plunger for a high performance fuel system pump for supplying high pressure fuel directly or indirectly to the cylinders in an internal combustion engine, said plunger being operably positioned to reciprocate at a minimal optimum diametral clearance of 76 to 128 millionths of an inch within an axial bore in the fuel system pump body to deliver a controlled volume of trapped, high pressure fuel at desired intervals directly or indirectly to the one or more engine cylinders, wherein said plunger is made of a wear-resistant high hardness, high thermal expansion ceramic material having a thermal expansion coefficient greater than 6.times.10.sup.-6 /.degree. C. and a hardness greater than 800 Kg/mm.sup.2, and the plunger is sized relative to the axial bore to maintain said optimum diametral clearance therewith to reciprocate freely within the bore without sticking during fuel system pump operation.