How rev-happy are Zs?

[Alfadog]

I'm feeling that something is amiss with my 240z as in normal driving I feel as though at about 2000rpm I should change gear. Is this normal ? Also, I've revved her pretty hard but it's quite hard to get up to 6000 and I've only ever been there once - let alone anything higher. It just doesn't *feel* good for the car if you know what I mean.

Also, at those high revs it feels like the car runs out of puff...

How would you describe the *feel* of a Z at the different rpms ?

[Phacade]

It should be somewhat solid reving through the band up to 7000 rpm. You mentioned that feels like its out of breath. It might be. I would check your fuel pump, fuel filter, intake to make certain its getting enough air, mixture in your carbs (or injectors if EFI). If EFI check AFM. You might check your compression, check timing chain for slack, valves could be burnt, etc. Sometimes carbon buildup in your intake can do this as well. Check your exhaust, if severly dampened it can reduce higher end running. Check timing. Check travel of petal and linkage. Check belts for tightness or slack. Harmonic balancers can benifit from a good lookover; sometimes if off center they can pull enevenly and reduce RPM.

Just a few ideas to get you started.

[hmsports]

One of the weakest parts of the z engine are the valve springs - as they get old, they get soft. This causes valve float at higher rpms and you will notice a bog down when trying to rev. I've had engines that won't rev past 5000 - just felt hollow - because of bad springs - new springs let her go to 6500. Freshening the head with a good quality valve job and new springs will help tremendously.

[Alfadog]

This causes valve float at higher rpms and you will notice a bog down when trying to rev.

Yep I've got that problem too.... mmm thanks !

Also thanks to Timberwolf I'll check out those things too (or at least get someone to show me :-/)

[grantman240z]

alfadog...i was having the same sort of problem before...but i when i stuck on the MSA turbo exhaust tip it seemed to solve the problem (i think it was exhaust backpressure). It will go up to about 6000...but it still just doesnt feel good for the engine like u said, it doesnt loose power, it just feels like the pistons are gonna go flyin through the engine block or something :disappoin . Ill get a valve job done and see if thats it...but it might also be the ignition secondary. Some other stuff to look at...let me know if u learn anything new.

[beandip]

I have a '73 but with and auto tranny. dont laff. It pulls strong up to 4K and then it shifts. Now I can manually shift and keep on up in the RPM range but I really like to drive this car and realise that it is stock and has overall over 200,000 miles on her and even with a rebuilt engine with about 100K on it I dont want to gernade the engine just to satisfy my eago. My brother in-law bought a $40,000. boat and he saw that the tack showed 5K as the red line and taking it out for a test run just ran it up to red line and ran it up the river,this was a brand new engine, well about a mile away he blew the engine all to hell. Case in point dont believe all you read and use your good cents. Yes new or near new engines will and can be run to the extreems in RPM . But for what purpose ? Do you like to work on the car or drive it ?? Also going fast costs bigg$$ keep that in mind.

[halz]

Redline is usually set as a ceiling which can be reached for limited periods but generally not for continuous running. Racing engines are built with greater precision to allow for continuous running at high rpm (close to the danger zone). When you're certain that carburation, ignition, valves, cams and springs are all ok, the best thing you can do to enable safe high rpm running is to have the engine balanced.