Momar

I was wondering how high you can rev with hydrolic flat tappet lifters if you have matching valve springs. I am assuming that the rest of the motor is set up for it. I just want to know when the lifters have problems.

Ben

five7kid

iTrader: (14)

I go to 6300 with no problems. Don't really want to, but it does it without complaining.

The cam card said valve float @ 6500 RPMs with their recommended springs.

F-BIRD'88

Depending on the design of the cam and the valvetrain
Generally around 6000/6500 is tops.
Your limited by the heavy lifter, limited usuable valvespring pressure on a hydraulic lifter, spring serge. etc
Some people use a "Rev Kit" to stretch this out a bit.

Generally, unless you have a huge camshaft,
you need to shift your car before 6000/6500 rpm
for best acceleration anyways.
If you want a big high rpm cam you'd be better off with a solid roller anyways.

AlkyIROC

I use anti pumpup lifters and shift at 6700.

iroc22

Yeah if you use a good anti-pump lifter, you can see higher RPM's. I generally shift at 6500rpm for the most power, but that's probably bumpin right off the redline.

Momar

How much do these lifters cost, and do they cause any problems for normal driving?

Ben

F-BIRD'88

Some "Anti -pump up" lifters have an increased bleed rate.
This can cause a mild ticking sound at idle simular to a solid cam.
The higher the bleed rate for a said oil pressure, the more noise.
Crane, Comp cams and Isky are the better brands
of hi-performance hyd lifters.
This and other factors (spring pressure, cam lobe design, internal lifter clearances and valving/metering) are used in the design of a high reving hydraulic cam valve train system.
Of course this costs a little more but you get what you pay for.