11-28-2009, 05:43 PM
You probably have a push rod type overhead valve engine. The cam shaft that operates the valves is located low down near the crank shaft and operates the valves by pushing up on the push rods. The push rod pushes against a rocker arm which works like a child's teeter totter to push the valves open. Only two things will mangle a push rod. Either the cam is out of time so that the valve is opened when the piston is at the top of it's stroke causing the valve to hit the piston, or the engine gets full of liquid. Liquid won't compress so either the valve bends, the push rod bends or the piston or connecting rod breaks or bends. Most likely the cam shaft is out of time. The engine needs to be torn down to where the timing marks on the cam & crankshaft sprockets or gears as the case may be are lined up correctly. If you install a new push rod without getting the timing correct between the cam and crank, you will just bend the new one. You have two timing specs onyour engine. One is the timing of the Crankshaft to camshaft and the other is the timing for the ignition.