Why 5 valves?

21 replies to this topic
  • John_Lorenz

Posted June 19, 2002 - 03:16 AM


Piston Go Up
Spark make Spark Uggggg
Gas go Boom
Piston go down
Piston Go up
Exhaust Valves open Ugggg
Bad Gass Out Wheeeewwwwwwiiiieeeee Uggg
Piston go down
Intake Valve open Ugggg
Good Gas come in
Go back to top Ugggggg


So that is caveman terms of what happens in the engine, So why 5, Becouse 4 is not enough and 6 is too many.....Uggggg

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  • motomike137

Posted June 19, 2002 - 05:18 AM


Motogreg hit on it. If you look at the available area in the head versus the area used up by round valves you use up a little more of the available space with the five valve configuration which potentially allows more air to flow. I think the reason they don't bother under a certain size cc is that the extra complexity and wieght is not worth the gain in airflow.

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