LD28 Fuel Settings

[koosjr]

Hi, I have been lurking here for a while.

I am using the Nissan LD28 in a Nissan Safari 4x4. The vehicle was originally equipped with the L28, so the conversion was almost a drop in.

The first conversion i did was on my Safari Pick-up and that was in 2005. It was not painless since the first motor suffered terribly from overheating because of a damaged top gasket.

Unfortunately the gasket sets that we can here at the parts shop that do stock spares for the LD28, are of really poor quality and the first top gasket leaked shortly afterwards and had to be replaced again. Unfortunately the guy who did the work did something badly wrong there and when I started the motor, the sound of the motor was very harsh. I told him there is something very wrong and on a the test drive it broke the cam after 30 km.

So I had another LD28 and again the top gasket was a problem.

I later bought a Safari SW also with a LD28, but this motor was fine for once and worked well. However, bad luck also hit me here and due to a series of events the motor ran without oil and of course knocked the bearings.

This motor was then rebuilt and again the top gasket was a problem. I got it to seal by over torquing the head and it worked well enough that the overheating does not seem to surface, but the cooling system is still under more pressure than it should be and constantly relieves a bubble of two through the cap to the expansion tank.

Thanks to someone who finally got hold of Victor Reinz head gaskets, we are now confident that the top gasket problem will be something of the past.

Information on these motors are really hard to get and since it was never a motor that was used in any vehicles in South Africa, very few people know the LD28. I spend 4 years before I could find the complete factory manual for this motor. The motors came into South Africa through companies that import these second hand motors mainly from Japan, but also other parts of the world where emission control is strict.

Even in the factory manual, there seems to be no reference to the power this motor should make. I originally thought is was a 69 kW motor with 200 NM of torque, but it now seems to me that the motor was more likely tuned for 60 kW (80HP) and about 170 NM or torque when it was used in automotive applications. I am surprised about this, since a diesel version of a petrol motor almost without exception, makes more torque than the petrol motor. Thus, power wise this motor does not seem to be a great success. Most people claim it is reliable though.

Apparently the 69 kW versions, was for agricultural and marine applications.

My question is: How can I tune the motor for the higher output? As you can imagine, it is a bit lame in a big brick shaped 4x4. Since these motors are turboed with the standard IP and injectors that are on there, I am pretty sure it should be possible to adjust the IP to the marine / agricultural settings.

Does anyone know where I can get those settings? I don't want to start messing with the diesel pump by adjusting the fuel screw on thumb sucking as basis. That normally does not give good results on diesel and I know these motors can quickly get heavy on fuel with the wrong settings.

[koosjr]

Have no-one here tried to go for 69 kW tune?

[rlaggren]

Use the "Search" button here or just read through the posts. There's a lot of info on the engine, power output, IP's and stuff.

Normally agricultural and marine applications are set up to produce LESS power because they run for long periods of time (days) under full load (vehicle service rarely uses full power for more than 10 minutes).

Rufus

[koosjr]

"Use the search function" is a very popular forum reply. I am no newbie to forums. The software is pretty standard all over.

I did use the search function and with all respect, these questions were not really covered with enough detail to make a comfortable conclusion. It is as clear as mud. I could not find any detailed alternative IP settings than what is in the manual, for example.

The topic that features the most, is the timing of the motor - and one really don't need to be Einstein to get the grasp of it.

The power and torque graph that is pasted on this site, is done to something like 2500 rpm because it is form guys who use the motor as a generator power plant. Pretty useless for automotive info.

So yes, after four years of some extensive browsing all over the internet for reliable info about something as simple as power output of the LD28, I can still not say I have found it.

[rlaggren]

koosjr

As you say, there is no specific exact how-to here. There is a lot of info from people who got part way there and related info on other engines with more modding behind them (the SD engines) which can point the right direction; the principles are covered with appropriate warnings about specific issues found. Each project will be different; there may not be any "right" answer - you build it and then tune it. But this is not rocket science and the there are sufficient guidelines to be confident that you can make improvements without breaking anything if you're conservative and careful and follow good engine building practices.

At this time I know of no torque curves available for this engine outside of the JESCO reseller's site and they have recently dumbed down the site so those may not still be there. If you want factory charts and many detailed cook-book how-to's to compare and answer all questions you need a different engine - there're not enough LD28's out there to generate that kind of data. Or you need to dig up one of Nissan's original LD28 engineers who still has some paper on the engine.

You could consider a Cummins 4cyl engine. They are popular with the off-road crew and there _may_ be more data on them and more "projects" to serve as examples and answer you questions. There is also the "33" Nissans with the factory turbo.

But it sounds from your initial post that you have some very basic issues having nothing to do with modding data but with just getting a good build in stock tune. Mechanical detail work can be hugely frustrating but unless you have a solid engine from which to start, all the modding info in the world won't help. You need to find (or become) a person who can trouble shoot, build and blueprint an engine reliably and consistently. Do you think somebody who put together an engine which broke the cam shaft in 30km will do a whole lot better having torque curves available? How can you know what might be needed in the way of power tuning if you start with an engine that already has a cooling problem?

I'm sorry you didn't find what you wanted yet. There are people here who know much more about the LD28 than I do and perhaps if they see a way to help they will chime in. In any case good luck with your projects.

Rufus