Commonly known as Cam timing the sync of the pistons to valve opening is a crucial matter. Fortunately syncing these two up is not a complicated matter as there are alignment marks to guide you so long as:
1 The piston has not come in contact with an opened valve
2 you have a basic repair manual to guide you
3 never spin either the crank or cam with the belt / chain disconnected
Valve timing and injection pump timing will be lost if you remove the belts.
using a service manual, check the timing marks and make sure they are in the correct locations. for a start then read the manual for a rebuild. not to tear it down and sthat but to find out how to retime the engine properly.
I'm young and inexperienced with practicality of fixing engines. I know most on theory only, but there is one question I can not find the answer to. Is it possible the pistons and the valves become out of sync while tinkering arround the camshaft without the belt attached to the crankshaft. If you don't get where I'm going, I mean like the intake valve to be open when the piston is at some possition that is not "intake". Ex: Intake valve opens, piston goes up, pushes the air out instead of taking it in, drops down creates a vacuum, and so on and so on and tottaly trashing it. Is this possible or is there some sort of syncing mechanism that I'm not aware about.
I am planing of cleaning the engine block of an old Opel Kaddet E diesel, from 10+ years of unchanged oil. The engine is siezed because of that sludge that has formed after not being started from a year now. It was gonna go to the scrap anyway so why not give it a try. Best thing that can happen is for it to live again, so I'm using it as an experiment.
tl;dr can the valves and the pistons get out of sync?
