How do I make my 600 fazer faster?????

[mr self destruct]

[quote author=mr self destruct link=topic=755.msg94928#msg94928 date=1376718017]



A higher lift but equal duration cam gives engines more low end torque, as a rule it's the duration and overlap that give an engine more top end power.

I can't get my head around why this should be. Can you give a fairly simple explanation for a very simple person?  :rolleyes :lol
Or do I need a degree in Physics/engineering? :book :eek
[/quote]


This:

Its all about valve opening timing. The more overlap you get, the more air/fuel you get in, and the bigger the bang (but only when the air speed onto/out of the cylinder reaches a higher velocity) hence higher revs. Less overlap, but wider valve opening is making use of the slower air velocity at lower revs, producing more torque. Its a fine line, but its one that works. simplisticly complicated springs to mind!

At higher revs, the flow of burnt gas (which is a fluid and has mass & momentum like anything else) out of the exhaust port helps drag the fuel/air mixture in the intake port.

This is also true at lower revs, but the help it gives the incoming gas is fish piss in the sea. To get round this, a high lift, short duration cam allows more mixture in in the same amount of time as a standard cam. Obviously then the valves have to lift faster due to the steep ramp on the cam lobe, and this causes a problem at higher revs as mentioned earlier in the thread.

Simply put high lift cams just leave the intake valve open for slightly longer on each stroke to take in slightly more fuel air mix, which in turn gives more grunt but like already said its a fine line,

Afaik this can be put to better use and get better results on a fuel injected engine that can be mapped but that's neither here nor there

Not quite. A high lift cam opens the valve by a greater amount for the same duration, a higher duration cam opens the valve for more time. Its getting the right combination of the two for vehicle's purpose that's the trick.