What is safe rev limit for stock '78 280z?

[rossiz]

i've done a bit of searching, but can't find anything definitive about safe revs for my '78 280.

to be clear - this is a DD and i'm not drag racing or autoxing, so i'm not looking for the very last pony out of the engine, but i'm really not used to this motor at all (more familiar with old american iron) and i've been afraid to rev past 5500 because i have visions of something coming through my hood...

after sorting through various fueling and electrical demons, the car is running fantastic (finally) it's really addictive to wind it up and send the rear end sideways (on a closed course, being driven by trained professionals only ) but i don't want to break it.

i know there are "theoretical limits" to the design - that's not what i'm looking for either, as it's a 35 yr old motor and i need to keep it reliable. so how far can i push it on a regular basis without shortening it's life prematurely?

[FastWoman]

I don't think you'll hurt the engine, but driving like that on a daily basis can be hell on the rest of the drivetrain. I think the Z can handle it as well as, or better than, most cars, but it's still hell on any car.

As to how far you can push without shortening the life? Well, we sent my stepson off to college with an automatic transmission Ford Taurus, which he drove in a very spirited manner -- hard acceleration, hard braking, hard cornering, not slowing for speed bumps, etc. The car is tough, but it came back in somewhat deteriorated condition. My point is that running a car hard will shorten its life. Common sense, really.

But that engine is tough, even at 35 years of age!

[Jetaway]

i've done a bit of searching, but can't find anything definitive about safe revs for my '78 280.

to be clear - this is a DD and i'm not drag racing or autoxing, so i'm not looking for the very last pony out of the engine, but i'm really not used to this motor at all (more familiar with old american iron) and i've been afraid to rev past 5500 because i have visions of something coming through my hood...

after sorting through various fueling and electrical demons, the car is running fantastic (finally) it's really addictive to wind it up and send the rear end sideways (on a closed course, being driven by trained professionals only ) but i don't want to break it.

i know there are "theoretical limits" to the design - that's not what i'm looking for either, as it's a 35 yr old motor and i need to keep it reliable. so how far can i push it on a regular basis without shortening it's life prematurely?

The redline on my 240Z is 7000, I assume the same is true for a 280Z. Out of deference for its mileage (200,000+) I use 6000 as the high shift point. But don't sweat bullets if I overrun it in 1st or 2nd gear. OTOH 85%+ of my shifts are between 3000 and 3500 and close to 99% occur at less than 4000. The wear equation is simple and universal, all else equal, fewer (no pre-detonation) revs per mile = more miles per engine.

Chris

[Captain_Zeros]

280z redline is 6500 rpm. It has a shorter connection rod to stroke ratio than the 240z (7000 rpm redline) because that extra 0.4 liters had to still fit under the hood.

On the stock tach there is also a "yellow" zone for 500 rpm below redline on both cars which the manual suggests not routinely using.

But as people have said above, those numbers are for a new car off the dealer lot, not one that's coming up on 40 years old.

[Zed Head]

If it's a stock engine you'll probably find that there's not much happening with the L28 above 5500 RPM anyway. Lots of noise but not acceleration.

[rossiz]

got it - thanks for the replies. funny thing is the first thing that happens when i hit 5K is a horrible vibration/rattle at the shift lever bushing (ordered the bronze bushing upgrade) which is so disconcerting i immediately back off.

i had noticed that the ponies taper off pretty rapidly after that, so no real desire to dip the needle into the red, but just wanted to know in case i got a little pedal-happy...

[ktm]

If it's a stock engine you'll probably find that there's not much happening with the L28 above 5500 RPM anyway. Lots of noise but not acceleration.

Peak torque is typically around 4000 to 4200 rpm on a "stock" L-series engine and falls off rapidly. Revving to 5500 RPM as Zed Head stated is about the best you can do.

Here is a good thread to show what I am talking about:

http://www.classiczcars.com/forums/engine-drivetrain-s30/13782-dyno-results-what-do-you-think.html

[FastWoman]

"bronze bushing upgrade"

Yeah, I have that too, but I don't know whether I'd call it an upgrade. The shifter is really nice and tight, but that RATTLE/BUZZ is really annoying. Anyway, I wouldn't be afraid of that noise. It doesn't really signify anything, except that maybe the nylon bushings are a more civilized choice.

[LeonV]

280z redline is 6500 rpm. It has a shorter connection rod to stroke ratio than the 240z (7000 rpm redline) because that extra 0.4 liters had to still fit under the hood.

On the stock tach there is also a "yellow" zone for 500 rpm below redline on both cars which the manual suggests not routinely using.

But as people have said above, those numbers are for a new car off the dealer lot, not one that's coming up on 40 years old.

The 280Z's redline is lower because of increased stroke. It has very little to do with R/S ratio.