LD28 with 280ZX turbo

[odie]

OK, another turbo question thread...mainly since ther is a cheap 280ZX turbo car for sale here.

Some say it's a bolt on & some say you need to modify the manifolds and little. Still sounds bolt-on "able".

I guess the main issue is fuel delivery. Do you need to change anything on the IP? Or higher flow injectors?

The old Mercedes use mechanical injection and are turbo charged. So how do they do it and can it be duplicated on the LD28?


EFI cars vary fuel flow based upon all kinds of inputs and sensors...but mechanical diesel injection has none, including 80's Mercedes TD.

[asavage]

Some say it's a bolt on & some say you need to modify the manifolds and little. Still sounds bolt-on "able".

The exhaust manifold will more-or-less bolt to the head. Two people have done it. It requires some clearancing work (Dremel-like, not chop-saw).

Plumbing is all custom: oil lines, coolant lines (if using the 300ZX turbo rather than the 280ZX), intake, intercooler, and exhaust (or exhaust adapter).

I guess the main issue is fuel delivery. Do you need to change anything on the IP?

No. See this post

Or higher flow injectors?

No.

The old Mercedes use mechanical injection and are turbo charged.

And use inline IPs, don't forget that. The MB TDs should be compared to the SD33T, not the LD28.

So how do they do it and can it be duplicated on the LD28?

The engine you want to compare to is the Volvo (VW) turbo Six in the early 80's Volvo 240/740 series. They use a Bosch VE IP similar to our LD's IP, and have a boost compensator for fuel delivery. I am going on the assumption that a competent IP shop can glue the boost compensator that VW (and others) used, to our IP. However, for low-performance it appears that boost compensation isn't needed. Only if you want higher performance does some way of getting more fuel squirted during boost become necessary.

EFI cars vary fuel flow based upon all kinds of inputs and sensors...but mechanical diesel injection has none, including 80's Mercedes TD.

Not true.

[asavage]

The Bosch boost compensation device is colloquially called the LDA (short for a German term).

The distributor type BOSCH VE fuel injection pump was chosen and adapted with a boost pressure controlled full load stop (LDA), The working principle is assumed to be well known. The maximum fuel delivery is 0.0365 cc per stroke at full load at which injection timing is varied by 8 degrees of cam angle. Injection timing is set by measuring the position of the distributor plunger when the cylinder one piston is at top dead center. The distributor injection pump with LDA is shown schematically in Figure 13. The LDA determines the fuel quantity in the middle and upper engine speed range, corresponding to the boost pressure level. At very low engine speeds the LDA is not operational because the boost pressure is not sufficient to overcome the spring preload.

When the control pin moves vertically, the stop lever rotates and the control plate is pushed in the direction of greater fuel delivery, i.e. to match the increased charge air quantity. In case of a failure of the turbocharger, the base ratting becomes effective, resulting in smoke free combustion.

More info at this page.

[odie]

Hmmm, some myths and assumptions about MBs dispelled...

I'm expecting to have to do some low tech mods to match the manifold & head ports as well and some altering of exhaust and intake plumbing. But that is relatively easy stuff.

leaving the LD28 IP "stock" , what if any do you gain from installing the 280ZX turbo & plumbing?

And how easy is it to tweek the IP for a little more fuel? Without any provisions for the variable nature of the turbo boosting over normal driving, can you just "turn up" the IP for a "best guess/ best compromise" fuel delivery?

[RT]

Hi, Richard is my name. I just found this site, and I can relate very well to your modification interests and I also may be able to help as I have turbocharged and intercooled an LD28 with turbo and manifold off an R31 L series petrol (Gas) powered skyline. I have been planning for a long time to do the injecter pump modification that you plan, with an LD28 IP married to parts from a LD20 Turbo IP which I have. I cant find instructions on the LD20 turbo IP to carry this out. If you have any other Q's on your particular modification I am happy to advise on how I've found from personal experience. I am a mechanic by trade.....Just so you know.

[Midnightz]

Hi Richard,

Could you share how you turbo'd your LD28 such as photo's, links...etc?

TIA!

[RT]

Yes, I'd love to! I'll just have to gt the digital camera out after work this evening and j-peg them to you. I'm just about to go to work today so ive got to go now. I'm in Perth, Western Australia, moved here from New Zealand 5 years ago with my LD28 powered car which was imported (the motor) into NZ by the thousands, and transplanted into many vehicles. Where are you? somewhere in America I'd guess?

[TheDieseliminator]

Hi Richard, welcome to the forum. What size diameter exhaust do you have installed in the vehicle and do you know how much power the turbo-intercooled LD28 is making. Very good to have your knowledge on hand and thanks for your reply.

Salvy

[RT]

Hi guys
Sorry for the delayed response. Everything happened over the weekend and I didnt have time to do anything I wanted to.
My exhaust diameter is 85mm (a tad under 3.5 inches) and its dyno'ed at 180hp.
Grinding edges of exhaust manifold ports to align with LD head mounting bolts from the L series petrol is correct. The only bolts that don't have an area to grind back to suit are 2 across the top. Ive cut a large nut in 1/2 and mig welded(seems to hold fine to cast iron) each 1/2 onto the top of these 2 exhaust ports so the large flat washer under the mounting bolt has support for both sides between each manifold(see pics). The Turbo is a T3 with the 50 trim compressor assembly replaced with a 60 trim. The exhaust housing size is a 0.48. The exit point from the turbine has been laithed out on a taper to roughly 3 Inches, as large as the housing allowed. then a 3" pipe and flange exiting the turbo thats expanded to the 85mm pipe, from there to the back of the car with a few hotdog straight through type mufflers.
As for the fuel delivery, it can be easily adjusted to suit at the IP max fuel delivery screw at the top rear of the pump. Its a 13mm lock nut usually sealed by a lead lug on tiewire trough a hole in the side of the nut. Cut it off and get rid of it and loosen the nut to then screw in clockwise the bolt about 1/4 of a turn. THEY ARE VERY TOUCHY>>>>A SMALL AMOUNT IS NEEDED. This will probably near on double the fuel delivery rate. When driving you need to feather the accelerator until boost starts then you can increase acceleration to match extra air with fuel delivery.To fine tune it get some1 to follow you with max boost and hard acceleration it should be a small amount of black smoke visible. If you accelerate fast with no boost all you get is piles of black smoke until boost is up and then you are faced with some very angry motorists behind you.....ITS NOT good for road rage !!!!!! not to mention engine wear due to excessive fuel. Im running about 12LB boost, which it handles fine for normal driving but dont expect to be able to tow big items on that boost continuously as you'll crack the head between the valve seats and it will drop the exhaust valve seats!...I have had experience with this before....grrrrr. My car is a 1972 Datsun 240C. I'd like to rename it a Datsun 280DT. Its BUTT ugly, needs SERIOUS restoration, but it GOES!!!!!. For those interested it will do a high 16sec 1/4 mile.
My wife and I are gonna try to ad some pics...but as we are both novices dont expect too much from us. HA.....stay tuned we're still trying!!!!!! FRED...Flippin Rediculous Electronic Devices!!!

[/img]

[RT]

http://s189.photobucket.com/albums/z120 ... bo%20pics/

Copy and paste this link into your browser and you should be able to see the pics I took. I havent labeled them but I figure you'll know what you are looking at anyway.

Any problems, let me know.

Richard

[davehoos]

i was look it the insulater pipes for you oil heater.

i was trying to work out what the the pipe conected to the dump pipee/exhauste is for.is it exhaust or are you heating something inside it.

[RT]

Ahh.....now...this kinda opens up an entirely different topic....Or a big can of Questions. The pipe you are referring to is a 250mm long 6mm diameter copper pipe to heat the cooking oil/lard to over 100deg C before entering the IP. The rest of the maze of pipes is engine coolant heat exchanger feeds to heat fuel lines and filters etc. I start it on Diesel 50c worth to melt the fat in the tank, lines and filters to then automatically switch it over to run on the fat. At the end of the journey purge the IP with diesel so it will start again when it's cold. look up WARFA on the internet(as shown in the rear bumper sticker and tail pipe pic).