Valve lift vs rpm theory???

[jsf74]

If rules state a cam of 500 max lift which is supposedly supposed to be rated to 6000 rpm is ran past that will it continue to make power. It seems everyone is turning 7000 plus but is it really doing anything but putting added stress on the motor? Seems most smaller cams would reach there max power production way before 7000+.

[steveshawjr]

it all depends on the cut of the camshaft. running solid cam you can get a 5l0 - 520 lift to meet the rules it all depends on valve lash. rpm points verry cam to cam . alot of it has to do with putting the car in the best torque range for comming off the turns

[let-r-eat]

If rules state a cam of 500 max lift which is supposedly supposed to be rated to 6000 rpm is ran past that will it continue to make power. It seems everyone is turning 7000 plus but is it really doing anything but putting added stress on the motor? Seems most smaller cams would reach there max power production way before 7000+.

There is a ton of variables involved here. Heads/compression ratio/valve size/cube inch/carb size/weight of car/min rpm.............just to name a few.A .500 lift cam can feed a bunch of rpms with the right induction system. You could put that .500 lift cam with 250 duration in a 358 cubic inch 9* dart headed engine and feed 8000+.A ton a factors here.

[perfconn]

There are many aspects of a camshaft.Lift versus rpm is not one of them.On the intake lobe you have duration at. 050 and duration at. 200 and then you have lift.On top of that you have what degree the intake lobe is ground on and where you degree it in at.You have all the same stuff on the exhaust lobe along with the lobe seperation of the intake and exhaust.The one most affecting how an engine will run is the intake duration.Intake lift and exhaust lift and duration have minimal effect on performance of an engine.If you get the intake duration right you can miss all the rest a little and still have a good engine.There is no relationship between lift and rpm.

[jsf74]

Thanks I guess I put too much value in valve lift alone. Thanks for the info.

[racer69]

@ Stockcardriver....That cam was awesome! Ran them some myself!