Mercedes diesel non electronic
 

Hello,

I am a newbie, just registered today 26 Oct 2008. I have a Mercedes 1989 with a swap engine installed, a diesel RD2800 from 1996. , naturally aspirated engine from 1996.

Have not a car computer so need to connect several analog signals and some digital that I can find from the car.

I have the ideas as how to proceed.

My only problem is to connect the Max Serial free Duino module or such to a LCD display. My notebook is great but I want a permanent monitoring in the car.

I am very happy to discovering this site :). Thank you all for share your experience and knowledge with the newbies.

Hello, oldbeaver. Welcome to EcoModder.

A Nissan engine in a Mercedes? That's the first time I've seen that.

I can't answer your question about adding fuel economy instrumentation, but I'm going to move your introduction to the Instrumentation forum. I think you'll have better luck getting a reply there.

Darin

putting any sort of instrumentation to track fuel consumption on a non computerized car is very difficult. For a mechanical injection pump equipped diesel engine you would need to have a metering pump feed it just to track how much fuel is flowing to the engine. From that you could take a reading from the speedometer and calculate your fuel economy. This is not a simple task.

WOW! A nissan diesel? I'd like to see that! How does it run/drive in that car?

Nissan Diesel Engine in a Mercedes
 

Well, thank you for posting.

The Nissan RD28 6 cylinders in line, is running fine on my Mercedes, very well, after a series of adjusting moves. Not easy!

First of all, this engine fits exactly in the Mercedes 300E engine space. I used a Jatco automatic transmission, which is slightly bigger than the original MB. So, some "hammering" must be performed below to fit that in. But the mount of the transmission matched the one of the car.

The engine mounts do not match, so some adapting work must be done for that.

The beam that goes from the transmission to the differential (I don´t remember the name in English) has to be cut and soldered, and balanced.

I put new original front shock absorbers, as to support the 80 k increased weight of the engine.

An air filter must be added. I adapted a Peugot diesel air filter.

The engine starts easily, after putting new "spark" plugs (I don´t know the name in English).

The battery was upgraded from 65 to 80 Amps.

A good electrician was necessary to make instruments work. He couldn´t make tachometer to work, though. I discovered that the RD28 has a tach signal output which I manage myself (with the help of some internauts) and a local MB mechanic) to transform to drive the MB original tachometer.

The air conditioning was taken out, as it means a lot of weight, takes space, and consumes fuel. Here in the coast of Chile, air conditioning is not necessary.

The vent bents with high rpm, so it reached the old radiator and broke it a little. A new hand made radiator for the engine was made from copper, same size but three rows instead of two. A new MB radiator was more expensive than the Nissan engine. I have to move it slightly forward to fit in. Some differences on the water input and output, to match ports in the RD28 engine.

After all that, the car run reasonable well and smooth. But it was too slow climbing hills. Reason: the final ratio was long too far. In fact, the MB original differential has a ratio of 3.07. The Nissan Skyline diesel that comes with this engine had a final ratio of 4.

I searched a lot and the best I could get was a MB differential for W124 with a 3.47 ratio. Made the swap and Wow!, now I have a good car.

The transmission is still smooth and uses the same original lift handle. The car is fast to start on a traffic light, go up hills very well, and has a very good kick down response.

Engine rotates at about 2000 rpm at 100 km/h and 2200 at 110 km/h. That keeps the engine cool. Maximum speed I have tried was 160 km/h at about 3200 rpm. This engine can run up to 4500 rpm, no problem.
A. Transmission has 3 speeds, plus overdrive. It locks at about 95 km/h. So, you feel like it has 5 speeds.

On the road, the car yields 14 km/lt (39,55 mpg) at 100 km/h (62 mph). It yields a good 12 km/lt (33,9 mpg) at 120 km/h (75 mpg).

This is a lot more than the original MB gasoline engine. Considering that diesel is cheaper than gasoline, I have a saving of about 40%.

Finally, I added an extra AT oil radiator to keep transmission well cooled.

Summarizing, I am very happy with the car. However, it cost about 4,000 USD to make the swap. I sold the old engine and transmission in about 800 USD. I may recover the investment in about 4 years.

I do not recommend to do the same to everyone. It is too risky, has a lot of trouble. For me was very pleasant as I put a lot of me on the work. But I think it is better to most people to fix the old MB gasoline engine, or even better, fit in a refurbished MB diesel engine. There are some Korean engines which claim to be identical to MB ones. I couldn´t get one.

But undoubtly, Japanese Nissan RD28 is better than any Korean engine.
It may be even better than a MB in many aspects. Specially cost, noise, vibration. But a refurbished MB in the US must be easy to get. And it will fit just away!

The sound of the RD28 is very pleasant and vibrations are very little. It is a smooth engine, appropriate for a Mercedes. In fact, noise is less than that of Mercedes diesel engines for the model.

The engine was made on 1996, and it will probably last more than me. I love my car. I wanted a smooth, stable and secure car, but cannot afford an expensive car.

Here you must pay a yearly permit for using a car, which is very expensive for a new Mercedes or any less than 10 years old cars. Maintenance of Korean or Japanese cars is expensive too, and they don´t run like a Mercedes.
I permit for a new MB will depend on the model, but it may cost as much as a small new car, and more (USD 10,000 a year). I pay 80 bucks.

That is what I can tell you about my car.

What else do you think I may do to increase the yield of my car? Aerodynamics, hydrogen, forced air intake, an electric motor?

I would like to hear from your experience with diesel cars.

Best,

Old Beaver

RD28 in an old Nash
 

Honestly, I never saw one before but I think there is a possibility for that THOUGH it would require some major adjustments on the engine.

RD28 diesel engine in a NASH: final ratio issues.
 

Hi Mauricio,

You wrote: "I'm trying to fit a RD28 in an old Nash 1956 (rambler model). This car has an original rear ratio of 4.2 (too slow, I thought)..."

I say: No, I think this ratio is PERFECT for the Nash. The original ratio of the Laurel diesel was 4.08. It may be too short, but only a little. You can fit larger tires and it will be nice.

You wrote: "and I bought a Dana 30 with 3.07 ratio". Here there are no hills but maybe this ratio is too fast. How was your car with this relation in horizontal terrain?"

I say: My car had a 3.07 final ratio standard. The car was too slow in horizontal terrain. No sprint at all. The fifth gear (lock, actualy) entered only at 110 km/h. This is very bad, as it is the gear with maximum yield. So the car yielded poorly also.

Yoy wrote: "Have you some technical information about laurels and skylines gearbox and differential available? I've a 5 speed gearbox, and you have an automatic gearbox. Is it relevant?

I say: Manual gearbox will give you a better control and some more yield. With a 3.07 ratio the car will move smootly, no doubt. But a little Citroen 2CV will surpass you on a hill.

You wrote: "You say that in the original car it was a 4:1 final ratio, isn't? It is the only available ratio or there are also faster? I thought that RD28 are similar as a naturally aspirated merc. 300D (88hp) and this engine comes with a 3.0:1 final ratio.

I say: I think you are wrong. Merc diesel has a 3.0 ratio, but Laurel and Skyline doesn´t. See for exampe these link:

R200 Diff Ratios - Hardtuned.net

You wrote: "But maybe the RD28 has less moment and higher rpm?! Maybe i must try the car first with the original ratio (4.2:1) and if it is too slow, I must change for the 3.07:1. What do you think about? Thanks and best regards",

I Say: Well, RD28 I have is a 1996 with 18 valves, and 100 HP of power. There are some older engines with 92 HP only (12 valves). And RD28 has higer revs.

I agree you should start with the 4.2 final ratio and see how it works.
There may be a gearbox influence between Merc and Skyline, because Mercs do not handle as high relations as Skyline.

Take you notes, make some tanks drives, see more comfortable speed for changing gears, and so on. Hopefully, use a tachometer.

Then, if you think it is not good, try your 3.07 differential and compare.

Good luck,

OldBeaver


mauricio.

Yeah, me too.. I never thought about having a nissan engine on a mercedes.. well, it is possible though.. Depends on which part, the configuration and all that..