Maximum Power for LD28?

[TABrinn]

What are the limiting factors of the LD28 for max power? I'm considering one to swap into a Datsun 240Z. So far, from what I've searched, a turbo manifold from an L28ET fits with some persuasion from a dremmel. I'm looking to boost the hell out of it so the stock L28ET turbo is doubtfully up to the task. Before I run off and blow up a perfectly good motor though, I have a few questions.

1) What's the max boost one of these engines will take without adversely affecting its lifespan too much? I read somewhere that the heads crack around the valveguides when the boost is cranked up too high. True? Any other durability issues?

2) Does anyone know where to get a nissan diesel performance cam or know of anyone who knows these well enough to come up with good cam profile #'s? All I can find is duramax, cummins, etc. Does anyone hotrod import deisels?

3) Is the IP rebuildable to handle the needed extra fuel? Or is there another IP that can be modded to work and be up to the task? Someone mentioned one off a VW.

4) Can a light weight rotating assy (forged pistons, con rods, lightweight flywheel) be used to free up some Revs, as in a gas engine or does the diesel need the added mass help smooth out unwanted vibrations? Note: I will be using a 5 speed tranny.

I know that's a lot to ask in a single post, especially from a newb! But this is the most informative site I've found so far!

[Dslsmoke]

1) I wouldn't go higher than 10 lbs, reason is, these engines (unlike the Ford, Dodge and GM) are IDI, or also knows as pre combustion chamber engines and thus have a very high static compression to start with (22.5 :1), if you boost them higher than 10 to 12 lbs you are risking major engine damage (BOOM!!!!)


3) I've heard some people using a marine IP or setting for one and gotten just a bit more juice out of them .


4) These engines run up 4800 to 5000 Rpm as is, Why would you want any higher?????


Hope this helps


Dslsmoke

[TABrinn]

I figured the higher CR had to do with it being an NA engine. What exactly would get damaged or go boom when 10 lbs is excceded? Would forged lower compression pistons let me run more boost? Or would it wind up pretty much equal: High boost with a low static compression or low boost with high static compression? I was thinking somewhere around 16-18:1 with around 20-30 lbs boost.

As far as the revs, I don't really need much higher RPM's but I'd like to get there in a hurry! Accelleration is a better word.

[diesel-man]

I believe a better place to start is how high performance diesels achieve exceptional results. I read a year ago about an Audi turbo diesel winning a 12 hour race at Sebring:
http://www.motortrend.com/auto_news/112 ... index.html

Anyhow, high injection pressure is one of the keys to lower smoke/greater efficiency. If you follow tractor pulling, you can see what others have done to make diesels competative. I'm not sure that many here have done much in the performance area.

On the turbodieselregister.com site, many people get into using larger turbos, (copper) o-ring the cylinder heads etc.

I have a supply of complete LD28s that you can practice on, $500 each.

[TABrinn]

Diesel-man, I'll definatly keep your offer in mind!

From what I've gathered on the other sights regarding diesels in general, you can boost the heck out of a diesel but will get little result unless the fuel is cranked up in proportion. Burning rich in a diesel is where you run into excessive EGT's and cause damage to your turbo or worse yet melt pistons! The problem is, none of the guys I've talked to know anything about import diesels and have no idea what to recommend for an Injection Pump that would be up to the task without overfueling. There is a Mercedes engine that looks very similar to the LD28 that's 3.3 liters (I think) and turbo. I have to research it further but I believe it is made by Bosch as well. Has anyone here ever swapped in IP from another make/model?

[diesel-man]

Possibly an injection pump off of a marine diesel (LD28) but definately a turbo ld28 pump from Australia, would make some power. I think you would have to talk to a diesel injection pump rebuild shop and pick their brain about raising pressure etc. 240ZD in the peddle it section has a gas turbo manifold and downpipe for you to start off on.

In uncharted waters, one ususally crosses the edge in the quest of finding it. Probably the cheapest power is bolting on a turbo and asking the injection pump rebuild guys what "knob to turn" to overfuel it. Unfortunately the only way to find out if 15 to 20lbs of boost is too much is to find the edge. Need some guage also.

If you burn a piston, you've still got a $350 crankshaft leftover. that's the only reason I say to not spend too much on the internals...yet.

[kassim503]

If your gonna turn her up, id definitley stick in a egt gauge so you wont burn any valves or pistons.