cam belts

[Road Racer]

How cam belts work

[KebabMeister]

A cambelt is simply a belt made of rubber/material and does exactly the same job as what a bike chain would do.  One side of the belt has sort of 'teeth' and they interlock with pulley gears on the crankshaft and camshaft. 

[Clare A]

Not sure how much detail Road Racer wants. I might be patronising him/her. It synchronises the movement of the crankshaft at the bottom of the engine with the movement of valves at the top of the engine, in a 4-stroke engine. (2-stroke engines don't have cam belts/chains). As the crankshaft causes the pistons to rise and fall, it's linked by the cam belt/chain to the end of the camshaft above the pistons, and ensures that the valves open and shut at a time that's most efficient for the pistons' rise and fall in the cylinders. The valves let petrol/air mixture in, and take exhaust gases out. If the cam chain/belt is loose, this won't happen efficiently.

I'm sorry if I've told you stuff you knew already!

[Road Racer]

Thank you ClareA.   The how cam belts work question was the heading for info, it looks like the actual info was deleted somehow, i'm getting tongue tied now, very nice of you to go to the trouble of the workings.   Here goes I have 1975 Citreon ZX when should the cam belts be renewed. PHEW !  Regards  Road Racer....