Jump to content
HybridZ

High Rev L28


Guest Anonymous

Recommended Posts

Guest Anonymous

can anyone recommend high rev kits for the l28 280zx or share some info on this as far as opinions on max rpm the engine can handle sets of parts or kits you have had a good experience with?

Link to comment
Share on other sites

L6 engines have been known to turn 9,000+ rpms. Generally those are high compression GT2 type race motors that get rebuilt every 5 to 15 hours of use.

 

There are no "kits" or "crates" for the L6 engine per se. Just not enough people out there to justify the design, tooling, and production costs for either of these marketing ideas. You'll have to talk with one of the known L6 engine builders (Sunbelt, Rebello, and Malvern), have at least $10,000 in your pocket, and a year to wait.

 

Why do you need a motor that turns high rpms?

Link to comment
Share on other sites

If you build the engine right and have it balanced, you should be able to turn it to 7 to 7.5k rpms. Getting over that gets you into a crank resonance problem.

 

Make sure you use ARP rod bolts, and spend your money on good machine work and bottom end prep.

 

I usually broke piston rings with my NA engines that I turned up there.

Link to comment
Share on other sites

Guest mongrel

I´m considering this;

use an L24 crank with L24 rods in F54 block with 3mm overbore.

This yields 2.75L like the L28, whith the higher crankratio and the thighter crank of the L24.

Be sure to use pisons (forged) that can handle the pistonspeed.

A shorter stroke crank will be less prone to resonanse and the higer rodratio vill slow piston speed down (less wear),this should be as safe at 9000rpm as a stroker 3.1L att 7000rpm.

 

This is what I´ve more or less desided to do, whith turbo. Happy hunting!

Link to comment
Share on other sites

You can make 300+ horsepower normally aspirated and 500+ horsepower turbo charged without exceeding 8,000 rpm in an L6. Anything over 8,000 rpm in any L6 requires more frequent rod bearing inspection and replacement.

 

Take the time and talk with engine builders like Dave Rebello, Don Potter, and Jim Thompson. They've all built dozens of GT2 type L6 engines costing five figures that regularly see rpms above 8,500 rpm. These engines generally need the bottom end torn down every 25 hours because of the rpms they see.

 

Its not as easy as just combining different parts from the Nissan bins.

Link to comment
Share on other sites

  • 4 weeks later...
Guest mongrel

Hmm, Rebello says an L24 can handle 8000rpm with propper prepps. Compare the rodratio on an L24 with that of a 3 liter stroker and you will find that the L24 has the same piston speed at 7800rpm as the stroker has at 7000rpm.

This ratio places less tensile stress on the rod, therefore making it less likely to fail.

With god aftermarket rods and a smaller, lighter flyweel Rebellos L24 engines redline at 8800rpm.

 

Well, it seems my 9000rpm dreems were a bit off on my budget, but one day I´ll get there I hope...

Link to comment
Share on other sites

You need to understand that it is not the rods that you really need to be worrying about, it is the crank. You run into resonance problems.

 

Get ARP rod bolts, and shotpeen everything. I would make sure my tolerances on the pistons were on the tight side, and use a good oil.

 

You must also balance the entire rotating assembly, and I would shim the oil pump to get some extra pressure. They say 10 psi per thousand rpms.

 

We built some engines we routinely turned anywhere from 7 to 8k, and they will do it, but it is rough on rings.

 

The lighter you make everything the better.

 

If it were me, I would spend my money on a turbo and make more power, and run less rpms to do it. I went to a turbo after going thru several NA engines, and it has been much better.

 

But I am working on an NA project just long enough to spank a few folks and then it gets the turbo treatment. If you are going to spend the money on forged pistons, why limit yourself to natural aspiration.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...