Patent ID: 7997248

Claim:
A valve guide for guiding a stem of a valve through a channel formed in a cylinder head which joins the upper portion of the cylinder head to an exhaust port, said cylinder head including a water jacket disposed near said channel, said valve guide comprising: a first portion which engages the channel near the upper portion of the cylinder head, a second portion which engages the channel near the exhaust port, and a recess portion situated in relation to the water jacket and between said first and second portions, said recess portion and first and second engagement portions being sized and shaped to maintain the surface temperature of the valve guide to prevent condensation of acidic gases between the valve stem and the valve guide, wherein the first and second engagement portions each have a select diameter which defines a tighter or looser engagement with the channel, and the diameter of the first engagement portion is larger than the diameter of the second engagement portion such that the engagement between the first engagement portion and the channel is tighter than the engagement between the second engagement portion and the channel.