Do most V6's have 24 valves? What are they for? (brief description would be fine)
Like a bath plug with a stem attached or an ice cream cornet with a straight cone, and these go up and down in the head to let petrol in and exhaust fumes out. They're driven by a cam which has lobes on it which sit on top of the valves on the end of the stem as the cam goes round and round the valves open and close at the specific time to open and close the valves. Got it now? Ask at your local library for books on internal combustion engines then all will be revealed in text and pictorially. You could also go down to your local car or motorcycle breakers and buy or look at a cylinder head, which as engineer goes is a very simple system.
Valves in an engine have two purposes. There is a set of valves to let the air/fuel mixture IN to the engine cylinders. Those valves then close, sealing the gas in for combustion. Once the fuel has burned, the outlet valves open and let the spent fumes out through the exhaust. Cars and trucks usually have 2-4 valves per cylinder. So, in a V6 with 6 cylinders, there could be anywhere from 12 valves to 24 valves. More valves typically mean that the engine can produce more power and be more efficient.
Valves fit into the top of the cylinder to allow the fuel/air mixture in (inlet) and exhaust gases out (exhaust) on older engines and a few more modern ones there is one of each to each cylinder. Later engines use two of each so that the cylinder can be fueled and exhausted more quickly. They are timed to open and close by means of a rotating shaft with eccentric lobes (camshaft) operated by the cambelt (or chain) from the crankshaft.
