Rev range? Is this right?

[red_dog007]

Well my tachometer redlines at 7k rpm. I think that this is some aftermarket tach. Isnt the redline of the L24 E31 motor 6k rpm with the powerband topping out at 5.6k rpm?

I just want to make sure that it is a 6k rpm redline just so that I dont kill the motor thinking that I can take it up to 7k rpm.

[Arne]

Nope. Yellow at 6500 and red at 7000 is normal for 240Z.

[Carl Beck]

But don't confuse a Red Line established 35+ years ago, for a new engine... for a safe Rev Limit for that engine with 35 plus years and 100K plus miles....

Unless you have owned and cared for the engine since it was new - pushing it to very high Rev's could easily kill it today...

Carl B.

[Arne]

Good point, Carl. Even my car, with only 60,000 miles on it will rarely if ever see much over 6000 RPM. Don't want to hurt it. Plus a stock L24 does tend to run out of breath about there. Doesn't do much good to spin it that fast anyway.

[JimmyZ]

There were a few times I missed a gear and slammed my tach. It seems that the points system went into flutter or something because the engine died. (Thank God) Must have been doing 9000 RPM+ because it was an unholy wine. Yes, the engine lived but I would have been pissed if I blew a hole in the block. Just had to restart and I was back at it.

According to a book I've read the 240Z can safely rev to 8000 , 260&280Z 7500 RPM. (mechanical limit in stock form) Ignition system won't let that happen though. Any move to an electronic system should include a rev limiter such as offered by Crane cams.

The book mentioned above is a good read.. The Design and Tuning of Competition Engines by Philip H. Smith.

Carl's point of metal fatigue brings up the good point that unless you have a new crank, rods, etc you should treat things as suspect and not rev too high. Regardless of any shot peening, polishing or heat treating an old part is an old part.

My 2c

Jim

[CanTechZ]

Here's a scan from my 1970 240Z owners manual describing tach operation. I really like the part about normal driving being "in" the yellow sector (6500 to 7000 rpm). As for driving with the tach in the red zone, what would you call "unless otherwise really necessary"???