Factory 302 lifters rpm limits

[Jimboslice751]

I have searched on other forums and stuff but can never find a good/consistent answer.

As far as I knew, the stock hydraulic lifters couldn't really go over 6000 rpm without floating the valves. But I want to try a different roller cam and rev to 68 to 7000 (engine is prepared for it so I know the rpm won't hurt it) but from what I've heard before I would need to run a solid lifter or aftermarket hydraulic lifter.
But others say that the stock lifter has no limitations? obviously I don't want to buy different lifters if the ones I have are sufficient (college is expensive).

What's the general consensus on what rpm the stock lifters are good to? Do I need to run different lifters to run to 7k? I know what else is needed in the valvetrain to do it just a question about lifters. Thanks

 

[Jimboslice751]

Nothing huh?

 

[wheelhopper]

I have stock lifters, and aftermarket valve springs. I run my car on road courses and regularly approach 6500rpm. I have hit 7000 on a few occasions with no problems, but the motor makes peak power below 7K so there is really no need to got that high.

 

[vortecd]

With a blower I was turning 7,000. Some of the NMRA Renegade guys were turning over 8,000

 

[Jimboslice751]

So really it's just springs? I've just read older things about them. From what I recall 6500 is the limit. Thanks for the help though guys.

 

[skipnay]

It really depends on the camshaft and how easy the ramps are. A steep ramp won't let the lifter keep up but a longer ramp can and will let the lifter keep up and some guys see over 7000 rpm with them.

 

[Jimboslice751]

They don't really advertise ramp steepness last time I was shopping around though. Wouldn't that be duration? and if you don't have much duration what's the point of reving to 7000?

 

[skipnay]

They don't really advertise ramp steepness last time I was shopping around though. Wouldn't that be duration? and if you don't have much duration what's the point of reving to 7000?

Yes they advertise ramp steepness. LOL I'm being sarcastic. Actually the only real way to tell if you kknow when the cam opens and shuts the valves and duration at different inch like 0.010 or even, 0.050. To answer your question about duration. No 2 cams could have the same duration just one opens the valve immediately and close's the valve immediately. You usually don't get rpm from duration, you usually get rpm from lift.