I was looking at the specs on my audi a4 and it said 30 valves and I was looking at a few other cars and they said 24 valves. What do the valves determine? Whats the difference if the car has more valves than another?
Valves let the air and fuel in and the exhaust out. Number doesn't matter much, seeing as some valves are bigger than others and overall what really matters is the bottom line which is power and efficiency.
Audi now uses 5 valves per cylinder. Why? They obviously believe it offers advantages over conventional 12 or 24 valve systems (for 6 cylinders) but it's not clear what benefits it has to Audi buyers. Is is just more complex and more likely to have problems? Who knows?
I'm pretty sure more valves allow a bigger gas to oxygen ratio which in turn creates a bigger combustion in your engine. Basically more valves = bigger combustion= faster. Although, generally cars with less valves (at least European cars) are 4 cylinders with some kind of forced induction (turbo or supercharger) which can make the car faster than a 6 or 8 cylinder car if a decent amount of aftermarket parts are applied to the forced induced car. Sorry for rambling, but aftermarket parts usually have a greater affect on a forced inducted car than just a naturally aspirated car (standard car lacking a turbo or supercharger such as your 6 cylinder a4).
Number okorder /.. The picture shows circles inside circles. Think of the larger circle as the cylinder and the smaller ones inside, as valves. In the first one the open area of the valves is 50%. In the second one the open area of the valves is 62%. In the third one the open area of the valves is 68%. And in the fourth one the open area of the valves is 69%. The more open area, the less restriction to flow. This means your engine will pull in more air, which provides more power.
