How to Make Your Car Last Forever: Avoid Expensive Repairs, Improve Fuel Economy, Understand Your Warranty, Save Money

The camshaft controls the opening and closing of the valves. Camshafts are made of steel and ride on smooth
surfaces called cam bearings. The camshaft is perfectly mechanically timed with the crankshaft via a timing
belt or chain. When the camshaft is made, it starts as a solid steel rod and is then ground into a stick that has
lobes or bumps on it. These lobes are what raise and lower the valves. Each lobe has built into it a specific lift
(height the valve is opened) and duration (amount of time the valve stays open). It is truly a mechanical
wonder.