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Title: cam: duration vs. lift Post by: nicolas on November 22, 2009, 15:12:58 pm Maybe this is one of my stupid questions, but i have been reading a lot and hearing things about these two variables in camgrinds, but i haven't been able to determine what affects what.
the way i look at it is this. there are two cams that are able to flow the same amount in their respective durations and lifts, but one is a highlift/shorter duration cam and the other is a longer duration/ shorter lift cam. what is the difference? as an example: why do some grinds end up with very low lift figures (example the V26)? is that designed for 1.5 or more rockers? or has it another purpuse? i compare it to a FK8 which has a higher lift (which looks about the same in numbers, but probally is all different in the end) can someone help me out please? Title: Re: cam: duration vs. lift Post by: RFbuilt on November 22, 2009, 17:54:52 pm i think valve size affects what lift/dur. we need ontop of the displacement and comp of the motor,
im not to sure (would love for the seasoned boys to chime) but port lay out (be it how the porter did it or the casting shape) would also dictate if super high lift is needed, or maybe just more duration , so to keep the valve open in the meat of the flow (area under the curve, of a flowsheet) atleast thats how i understood it on inline4 engines LOL ;D |