Hello friends!
I´m just beginning to build a Mercedes L 3000 S truck for a Afrika-diorama. As in that region the germans left the engine hood (bay) open, I have the problem of constructing a scratch built engine. does someone have photos and/or scale drawings and further information (type, power...) of the accurate thing?

Viking,
That's a tough question, I just did a Google search and only came up with a bunch of stores selling the kit and many pages on Mercedes cars.
Perhaps you could post the question on the rec.models.scale newsgroup.
Perhaps Kencelot, the link-meister, can come up with something?

I'm a Mercedes-Benz enthusiast, and will try to do a little digging for you. I do know this, it was almost certainly a six cylinder in-line diesel of about three and a half liters displacement. Mercedes had been fooling around with diesels for years before WW2, and produced the 260D sedan (2.6 liter I-4 engine) in 1936--the world's first diesel-powered passenger car. BTW, Diesels made before the modern turbocharging era look remarkably the same. Their isn't much external difference between that 2.6 liter engine of the thirties and my 2.2 liter four cyliner from fifty years later. HTH, and if I find anything more really useful I'll post again on this topic.
Greg

So far I've found some of the specs. I will keep looking for you!

http://www.wwii.home.ro/vehicles.htm



:-)

kencelot:
thanks for the specs-hp. it is a first step for me. I didn´t know this site so far.

greg:
that´s a good bundle of information. it will help my search technique.
while writing this i found some more:
http://www.tmb.z-insider.de/daten_63.htm
hopefully some will find the fotos too...

Viking, I just checked out your link to the type. My German is rusty, but the original factory specification sheets on that site confirm that the powerplant was a four-cylinder diesel, model number OM (oil motor) 65-3. NOT GASOLINE, as one of the other web links indicates! OK, then, I have a motor number. I'll look in my references on Mercedes-Benz at home this afternoon and see what I can dig up about that motor family. What I have is mostly books on the cars of the era, both restored and from the museum. I'll try to provide some titles and ISBN numbers. like I said before, diesel engines all looked remarkably alike so pictures of a car engine would be plenty good enough to guide you in scratchbuilding one for a truck.
Greg

OK, wrote too soon! I looked at the last picture on the page, the one with the chassis cutaway. Allow me to describe what the Mecedes enthusiast sees:
1.Six cylinder engine, with six into one exhaust manifold exiting the left side of the engine (viewed from driver's perspective.
2. Pipe from radiator to cylinder head running over top of motor to the rear of the block.
3. What look like a pair of one-into-two intake manifolds running into the top of the motor. What looks like two air cleaners are at the ends of this. Now, this looks a bit weird: the picture looks to me like this goes into the top where I would expect the valve cover to be, unless this was an L-head engine--that would be odd for Mercedes-Benz, even then.
4. In the top view visible between the two intake manifold assemblies is the injection pump, with six little circles on top. Those are actually hex fittngs, and each will have metal tube fuel line coming out the top that curves off to one of the six cylinders. These will all be curved so as to nest together and run in parallel with one another, and likely held in place with metal clips so they don't vibrate loose. New clips are plastic and a lady to get into place. I know this, having replaced all four fuel delivery lines on my 190D last winter!
5. Can't tell exacly, but to the front of the engine on both sides are the accessories--water pump and alternator, driven by belts, and a belt also appears to drive the cooling fan. Way too early for electromagnetically clutched fans like on modern-era cars. Scavenge this from some other engine and make hte area look busy. Trust me, it will be accurate enough! HTH,
Greg :-)

Just read my last post, so thought I should head off the inevitable humorous confusion and apologise for language . You see, the politically correct software changed a term that I used in describing the attachment of certain parts when working on my diesel. I should have been more polite, but the text as written will make more sense if one mentally substitutes for "lady" as translated. I was actually referring to a common English-language name for a variant of the typical canis domesticus animal, gender being of the female persuasion!
Greg

PS I'm really not doing this just to load up on posts!

Greg, it's a four cylinder. On the first sheet, Zylinderanzahl translates as Number of Cylinders (4), it then goes on to list cylinder arrangement (row=inline), capacity (displacement =4850 cubic centimeters), Bore, Stroke, Compression Ratio (17:1 really confirms that it's a diesel, 11:1 is really high for a gas engine), etc.
(love online language translators)

Let me preface this by saying I know nothing about Mercedes Benz engines, but I do work at a Cummins engine distributor - so I've seen a LOT of diesel engines. I think those intakes correspond to the four cylinders, each dumping in at the top of the cylinder, and through some strange valve arrangement, each cylinder has two exhaust valves, with cylinders 1&2 and 3&4 sharing an exhaust port between them. If you look closely you'll see that there are two cylinder heads, thus each head has two intake ports and three exhaust ports - resulting in what appears to be an exhaust manifold for an inline six. Strange arrangement though. That drawing would really be pretty good for a basic shape of the top of the engine, but no detail on the oil pan or the block cross section.

Yeah, Phantom, you're right..and boy do I feel stupid, confirming a four-cylinder in my first post and a six in the next! That exhaust manifold arrangement is what threw me. I agree, the layout is weird. I don't know why they would do siamesed exhaust ports like that, but I'll look at my pictures of the 260D sedan to see how similar it is. But I think the car engine has a standard four-into-one exhaust. Other than that this thing simply looks scaled up to be suitable for a truck. Compression of 17:1 was pretty good for the time; even 50 years later my car's engine is only 22:1. Newer turbodiesels from Mercedes are also running over 20:1 compression. Wish I could get one here . Anyway, thanks for correcting my egregious errors brought on by overzealous pontificating.

Viking, have you decided yet that you've got more than you bargained for here? I agree with Phantom that this documentation goesn't give you much for block cross section or oil pan configuration. I submit that this should not be a major concern for your model. Make yourself an educated guess and start carving a chunk of styrene. This kind of thing is creative gizmology, as Shep Paine once wrote. Even with the access doors open, enough will be hidden by the rest of the vehicle that exactness won't matter. Get the basic shapes right and nobody will know the diference. Well, nobody outside the factory museum in Stuttgart, anyway. Speaking of which, look up Mercedes-Benz.de (German web site) and see if you can't contact the museum from there. They probably have all sorts of stuff stashed away.
Greg

Any time Greg. :-)




I agree wholeheartedly - look at it this way, if it's this hard to find the infromation on the topic, then what's the possibility of running into someone that knows any better? And if you do run across that person, well, then you have to either pick his brain for info and rebuild the kit, or find a good place to hide the body.

-Paul

hi to all, who helped me so much. a german friend dug out this picture:

thanks to you, I think it´s ok already!

Another excellent picture, Viking! It offers some excellent clarification for your project. One can readily see the connecting rod for hte steering coming down through the firewall; the upper radiator hose angling down into the block just above the exhaust port for #3 cylinder (Mercedes-Benz ALWAYS numbers from front to back), and the two air cleaners for the induction system can be seen on the right side of the valve cover. This view does not show the injection pump; it is mounted too low on the right side for it to be shown from this angle. I DO see a little blob to the left (forward) of the left air cleaner, and that looks to me like a representation of the hard line going into the injector for #1 cylinder. Now that my foolishness has been corrected and we know we have a four-pot motor, make sure that you include only four injector lines going to the cylinder head. Also, remember that diesels need glow plugs to warm the pre-chamber before starting so you will want to use model car spark-plug wires for that. They should go into the head above each injector. Don't wire them up to a distributor! Just wire them to a box somehwere--probably the firewall. They only get used on cold start-up and all come on at once for a minute or two. Phantom, have I covered this pretty well for Viking? Any additions or corrections?
Greg

Sounds pretty good Greg, but I'm not sure about the use of the glow plugs. I don't know anything about Mercedes industrial diesels, but none of my modern day Cummins industrials have glow plugs, a block heater is about the only cold weather starting aid they have.

The intake side would be very simple, just the air cleaners, intakes, and the fuel lines from the injector pump. The injector pump would be a rectangular block, usually mounted at an angle with the Fuel lines in a row coming out of the top and driven by a v-belt and pully.

It looks like the alternator and starter are both on the exhaust side of the engine. That last picture should really get you close with a little creative scratchbuilding - you could probably get away with using an exhaust manifold from a Small-Block Chevy V-8. The intakes would be plastic rod filed at an angle and then glued together with a couple of sheet plastic flanges where they meet the block. The aircleaners can be the tips off of the caps of ball point pens. Steal the alternator or power steering pump off of the same car you took the exhaust manifold from to stand in for the rather large alternator on this truck.

Another idea, look around for models of 1930's cars or Model T Fords, a lot of times they will have an option of building the car stock instead of as a hot rod. You can steal the stock engine from that and modify it to be your diesel. I know the scale is different, but that 1:25 Gas car engine may be just right for your 1:35 diesel truck.

Let us know how it turns out Viking!

-Paul

Hi!
To Phantom:
Here is a first preview of the engine and the "underwork". Admittedly I did some "fake" job...


I will still need a lot of time to finish this awful work.