L28 Redline

[ozlime240z]

I have an L28 in my 240z, it was there when I bought it. I have no idea what it came out of.

I'm curious as to what it came out of.. but since it's an Australian car I suspect it's out of a 280C, or maybe a 280ZX, we didn't have 280Z's

Either way it has a F54 block and an N42 head.

My main concern is if it is out of a 280C how does this effect the redline. What is the Red line on the 280C? Is it as high as the 240? Or have I been over revving my engine

So I guess my question is what is the redline on a L28 with F54 block and N42 head?

Thanks In Advance

Ozlime240Z

[santamaus]

Same thing? My 240 has the stock gauges in it... how high do the L26 and L28 rev?

Thanks!

Chris

[Zvoiture]

I can't comment on a f54/n42...That sounds like something that was put together...and who knows how it was put together? Flattops?

I have a bone-stock innards in my L28 which in 77 (in the US) came with n47/n47. I have a K&N intake and headers with straight-out exhaust and I rev it easily and frequently to 5500 and occasionally to 62 or so. I tell you about the intake and exhaust because it did not rev to these levels easily before.

I have never owned a L24, but I have heard many people say it can rev higher. Of course, it all depends on how it was built and how it is running....Balanced? Polished? Knife-edged? ARP? etc. etc. etc......A decently put together L should be safe to 7 and a very well built L-series could visit 8?

steve77

[24OZ]

I've got an L28 from a 280ZX in my 240Z, it redlines about 5,500. But I never really take it past 5,300 very often.

I have the original 240Z Tach and it worries me when leaving my car for work or lending it to anyone as I'm thinking they'll look at the tachometer and push it into way too high revs.

[hmsports]

The weakest point of the Z's overhead cam when it comes to revving is the valve springs. They are not stout enough to handle much over 6500rpms. Over this, the valves tend to float. As the springs get weak, this limit is reduced. I would say it is not advisable to take a stock Z engine over 6K too often - and like Zvoiture and 240Z mention, 5500 is probably a good standard to shoot for.

[24OZ]

I agree and there isnt really any power left past 5,000 anyway, all your doing in unecessarily straining the engine and reducing its life.

This is my dyno results I had just bought the car at the time and didnt want to push it over 5,000 Revs but as you can see not that much power left up there anyway.

The L28 is stock apart from Cold Aird Induction.

Ignore run 1 and run 2 as they went a bit wrong, notice how they just sharply die off. Run 3 is as far as I know how its supposed to look like on a fairly stock L28 FI motor.

No extra torque after about 4400rpm, incidentally it peaked at 148ft/lb. I dont know why the other runs peaked over 150, I think they werent doing something write at the dyno centre.

Well anyway thats what it looks like for what its worth. I also think my seals are worn as occasionally I do smell oil when I push it so it probably could look better with an engine rebuild.