What does redline actually mean?

Thats were you should run the engine al;l the time to get the c most out of it . As the blonde said "all the gauges were in the red so thats Ok eh "

I learnt a lot from this thread that I didn't know beforehand.
Thanks guys. Impressed.

intrade wrote:

because after red line comes the rev limitter. and if that dont exists valve bounce would be next to come.
Valve bounce is when the piston is faster then the valve it bounces it closed because its all about physic why do you think 2 strokers can rev 12 to 18,000rpm because they have no phisical springs boincing abouts a spring is closing the valve on a 4 stroke , this spring can only phisically do it this and that fast.
Now a desmo system was supposed to overcome that spring -valve bounce only problem is physic also broke the arm whom was suposed to close the valve , if a mass is to heavy and is catapulted fast in one direction it becomes a imense force think bullets out of guns. [/quote

Desmo systems are redlined too - but are capable of higher rpm than spring arrangements.

What does redline actually mean?

The point on the tachometer where lines change to Red. The point where manufacturers recommend not to Rev there for very long.

Maximum continuous engine speed as recommend by manufacturer, a temporary intermittent higher speed or speed zone may be permitted.