350 ZZ4 crate MAX RPM

[TheRoaringEagle]

i'm looking to get a ZZ4 and the max rpm is about 5800. i was wondering how you could make this engine have a higher rpm range. not that i need it but just wondering what makes a difference. how do you get higher rpm range, and what does it do. are higher rpm ranges for high speed circle track racers? or for high end power?

does the compression ratio effect rpm range? what does?

thanks in advance, i'm a newbie with engines.


p.s. does anyone know what the max rpm was for a 1st generation camaro 302/z28 engine was?

[Lowend]

The compression does not directly effect RPM range. The #1 factor is engine RPM range is the camshaft, that said as you increase duration of the cam, you generally want to increase compression as well.
You can get a higher duration cam for the ZZ4, BUT it does have a hydrallic roller cam, and all hyd lifters pump up ~6200RPM so its not a great idea to rev it much past that.

The DZ302 had a factory redline of 7000RPM in street trim, and much higher in race cars.

[TheRoaringEagle]

cool thanks!

btw whatre the benefits for having a higher rpm range? it wouldn't be much help for street right?

[Scott Parkhurst]

Consider where horsepower comes from:
horsepower = rpm x torque / 5252

The greater the rpm, the greater the horsepower potential.

How that same engines acts at idle and off-idle (900-1,500 rpm) may be adversely affected by a camshaft designed to operate efficiently at 6,500 rpm vs. 5,500 rpm. So you may have to sacrifice some low-end drivability, vacuum, and idle smoothness to acheive higher horsepower from higher rpm operation. If you know this going in, you can make the best call for your particular combination.

Consider this: Will the car spend more time idling and driving in traffic below 2,500 rpm, or winding out past 6,500 rpm? Which is more important to you?

Build the engine to serve your needs most effectively, whatever those needs may be.

~SP~

[TheRoaringEagle]

ok cool, excellent eye opener, it seems so cool to have a larger range but it's not worth it for my cause. thanks!

[TheRoaringEagle]

hey just for thought,
you cannot use solid lifters with a hydraulic cam right? i've heard of variable hydraulic lifters that can handle a higher rpm and do not need valve adjustment. have you heard any information on these lifters - for the street - and would it be as simple as pulling out the lifters in a ZZ4 and dropping the variable lifters in?

thanks!

[Lowend]

variable lifters don't really do all that much. Part of the problem is that hyd roller lifters are very heavy.
I understand if you wanna go looking for RPM's, but that factory valvetrain just ain't gonna do it well.
You could always go "back" to a solid flat-tappet lifter setup (gasp) and go hunting 7K RPM on a budget

[nancejd]

There are solid roller cams as well.