[RallyBob]

Assuming a fresh set of late model (hydraulic cam) valve springs and other wise stock valvetrain, I've seen valve float at 7400-7500 rpms. But with peak power being made at 5200 or so, even 6000 rpms is redundant with a stock engine. The exception being the horrible 2-3 gear ratio drop, so it makes sense to hang on a bit longer in 2nd gear.

HTH,
Bob

 

[RallyBob]

so on the 2.0 im building......the stock valve springs can handle 6500 safely? also there will be a custom cam involved

As soon as the cam profile is changed, or valve sizes are increased (heavier valves) then the rpm limits are changed for a given valve spring pressure. What cam are you going to use? Solid or hydraulic?

Bob

 

[RallyBob]

You'll be borderline with stock springs (late model springs are 180 lbs). I'd try to get something with 210 lbs or so. Early springs are not sufficient at all (150 lbs).

Bob