Valve timing adjusting system for internal combustion engine

摘要

A valve timing adjusting system includes mutually parallel axial fluid paths both formed about a fastening bolt which engages with an axial bore formed at the end of a camshaft. One of the axial paths if formed through the fastening bolt and the other axial path is formed between the outer periphery of the fastening bolt and the inner periphery of the axial bore of the camshaft. This avoids necessity of formation of axial fluid path through the camshaft and thus redudes mashing step in production line to lead lower cost.