Für einen Nissan 2,8 Turbodiesel.

[glenlloyd]

I was surprised to find this TD head for sale on ebay germany. If the photo were better we could do a comparison between the LD28 head and what I assume here is the TD28 head.

Pictures I've seen of the TD28 engine look markedly different from the LD28, but since I don't have an engine manual for the TD28 I can't say about the other stuff.

http://cgi.ebay.de/Nissan-Patrol-2-8-Tu ... dZViewItem

steve a

[asavage]

The cam for the head in that pic isn't chain-driven. I think the TD may be like the RD28 in that respect:



The seller of that head (without valves) wants US$850 via Buy It Now!

[glenlloyd]

The cam for the head in that pic isn't chain-driven. I think the TD may be like the RD28 in that respect:

So does the RD28 come from the same basic family as the LD28 or is it entirely different? Is it a cast iron head or alloy?

The seller of that head (without valves) wants US$850 via Buy It Now!

Yes, that's a very healthy BIN price, there must be a lot of 99.99 silver content in there.

steve a

[asavage]

So does the RD28 come from the same basic family as the LD28 or is it entirely different? Is it a cast iron head or alloy?

When you obtain the answers to those questions (and snatch the pebble from my hand), it will be time for you to leave . . . er, well, just tell us.

(I hope the 'pebble' reference isn't to old)

. . . there must be a lot of 99.99 silver content in there.

Make that 99,99 . . . it's in Germany, after all

[glenlloyd]

Here's a pic I found of the RD28, with something of a cutaway on certain areas, other than the T-belt it doesn't do much, but there are some major difference in the front. I joined it to a bad pic of the LD28 from the same site, and you can see there are some major differences.

To me it doesn't look as heavy duty than the LD28 but that's just my impression based on the huge timing belt and extra plastic. I'd like to know if the head is still cast iron or now alloy, my inclination is that it's alloy but who knows.

The designation for the turbo version appears to be RD28T, and the displacement of the RD28 is 2825cc, 94hp non-turbo.



This picture is also of the RD28 although the pump mounting is lower, more consistent with the LD28, and the camshaft drive isn't shown for some reason. This is from a French site.



Steve A

[asavage]

Do you have the site URL where you stole those pics?

I don't like the lack of 180° minimum wrap on the cam belt. The IP has plenty of wrap, but the cam doesn't. That's got to make the peak belt tooth loading pretty high on that sprocket.

But then, I've never understood OHC on a diesel anyway. I can't think of any adavantage.

[glenlloyd]

Do you have the site URL where you stole those pics?

Stole is such a harsh word...perhaps I permanently borrowed them ...

http://vvvf.jpn.ph/~ara-masa/030430.html

Scroll down and select what you want from the list.

I don't like the lack of 180° minimum wrap on the cam belt. The IP has plenty of wrap, but the cam doesn't. That's got to make the peak belt tooth loading pretty high on that sprocket.

But then, I've never understood OHC on a diesel anyway. I can't think of any adavantage.

I didn't notice it at first but you're right, it's certainly not 180 on that cam sproket, more like 120. Another picture I found was of the tensioner setup for the RD28. There's a fixed roller and then an adjustable tensioner, which I think is the one we can barely see in the photograph.

Here's the French site link:

http://www.dta-moteurs.com/fmoteursnissan.htm

steve a

[fud2468]

Question: If the LD28 intake manifolds are being adapted for the Z-cars to be able to use turbos, why can't the Maxima diesels have turbos added too?
Ray Mac

[asavage]

Question: If the LD28 intake manifolds are being adapted for the Z-cars to be able to use turbos, why can't the Maxima diesels have turbos added too?

They can. But on a gasser you have several direct ways of altering the fuel mixture, because merely adding more air (and no more fuel) in a gasser with boost gives you a lot of heat and holes in the pistons. The path to doing this mod is somewhat well-beaten -- on the gasser.

Adding a turbo to a diesel, you get more air. Assuming correct injection timing and a slightly over-fuelled condition from the factory, adding more air via a turbo may yield some small amount of power, and a reduction in soot.

But if you can't add more fuel (and I can't think of an easy wasy to add more fuel that isn't chock full of big, nasty holes), then why bother adding a turbo? And there aren't (AFAIK) any bolt-on parts, it's all fabrication.

Changing the full-load adjustment to provide more fuel on the LD28's IP is a really bad idea. Overfuelling at low boost will lead to sky-high exhaust temps (a pryometer is an absolute must when you start playing with diesel and more fuel, and they're cheap to buy), cracking of exhaust manifold, blown head gasket, and -- you guessed it -- holed pistons, or at least melted upper ring land.

Other Bosch VE IPs that are installed on turbo'd diesels have a boost compensator that allows more fuel to be injected as the boost comes up. You can't emulate this with your foot, because your foot is not accurate enough to prevent mechanical damage. No, not even if you watch the pyrometer carefully forget it! And I don't have a source for a VE-6 IP from a turbo app that can be modified for LD28 use.

That's it in a nutshell.

[fud2468]

Well I was not thinking about injecting more fuel, would leave that alone. I seem to recall reading years ago that the early VW diesels got better mpg than the N/A's because the turbo provided additional air for more complete combustion and reduced smoke in the process. But maybe that doesn't apply to LD28's.
While I'm on here, another question:
On another thread you discussed the reduced sulfer fuel that will be phased in later this year.
Is there any kind of additive to diesel fuel that will provide proper lubrication for older diesels when this happens? I know you discussed biodiesel in that thread, IP seal deterioration, etc. but I'd plan to stick to pump diesel.
Thanks,
Ray Mac.

[asavage]

Well I was not thinking about injecting more fuel, would leave that alone. I seem to recall reading years ago that the early VW diesels got better mpg than the N/A's because the turbo provided additional air for more complete combustion and reduced smoke in the process. But maybe that doesn't apply to LD28's.

If your LD28 smokes, then you've got incomplete combustion and adding more air will give both more power and more mileage. However, you can get the more-mileage part by just backing off the accellerator until the smoke disappears. Voila! No more excess fuel.

I have not heard of increased mileage on the 1.6l TD VW with the turbo -- I've owned two NA VW diesels.

On another thread you discussed the reduced sulfer fuel that will be phased in later this year.
Is there any kind of additive to diesel fuel that will provide proper lubrication for older diesels when this happens? I know you discussed biodiesel in that thread, IP seal deterioration, etc. but I'd plan to stick to pump diesel.

I assume that the well-known additives would all suit. Diesel-Purge, Stanadyne's stuff, Power Service's stuff.

BD in low concentrations (ie under 20%) will also sub and for a lot less money. As little as 2% is adequate, so I've read. And your smoke will smell better -- yes, you can smell the difference in 2%.

[Dslsmoke]

Well i did the retro thing about 10 to 12 years ago and I can tell you this:

1) Reduced smoke emissions
2) Noticeable power increase
3) Better MPG
4) That unmistakable Turbo whine.

Modifications were kept to a minimum, no extra fuel, a 3" exhaust pipe without muffler was added, free flowing air filter, Diesel tach, boost and pyro gauges.

This baby has only 88K original miles on it and has always been maintained well, great cars!!!

I don't know how to upload an image here, if I could get some help, I'll post a picture of what it looks like.



Dslsmoke

[asavage]

I'm definitely planning on adding a turbo, have for many years, but I don't expect much from it. Mostly cooler exhaust and less smoke.

dslsmoke, I've PM'd you. Warning: I am very ill and probably won't do anything with pics for a while. And I'd like to see lots of pics!

[davehoos]

http://www.geocities.com/davehoos/rd28timingbelt.html

the IP is on the slack side of the belt.so it can jump teeth.the fixed idler is to reduce vibrations and belt whip .this is the spot that the gas version has the tensioner.IP bolts to the cyl head.

[fud2468]

Sorry to hear you're ill, Al. Hope you're better soon.
Yeah, ease up on the go pedal to reduce smoke will work, but then you have no power either!.
The VW I mentioned may have been a one-off and not like the production turbos. I have it somewhere in one of my old mags and will look for it when I get time. I do recall that it was a 5-speed and up to 80mpg was claimed.
Ray Mac.