Diesel transplant into 560SEL
 

As I understand it, the 560SEL was one of the last 126 chassis models. With a large and thirsty V8 gasser.

So just hypothetically mind, if one was able to get VERY cheaply a mint 560SEL body (grey leather, heated seats, etc. etc.) with a messed up engine, how complicated would a 617 engine and transmission transplant be? I guess the diff would have to be swopped too.

Are engine & transmission mounts, cooling systems and so on identical? I understand there would be some re-plumbing of climate control systems, vacuum, electrics and so on (ignition switch for example with shut off plumbing) but I am trying to estimate the complexity of this job.

Of course I have not seen the car so mint may be hyperbole - could be a rusted or crashed POS :(

Drop in an OM606 turbo at that point

The only way to do this would be to have a 300SD/SDL as a parts car. You will find that there are more issues than you think if you start doing this. The 560 SEL had a computer (primitive by today's standards) controlling the engine and I am not sure what else.

Motor mounts should line up into the W126 chassis, oil filter location should be OK if the engine is from a 300SD/SDL, you would have to re-wire a lot of the underhood and dashboard connections and plumb the vaccum lines. I am not sure about the location of the AC compressor, alternator, ps pump, etc on a 560 V8 so I don't know how badly those systems need to be modified.

There are also fuel tank/line issues to deal with, the different weight of the engines and therefore spring changes in the front suspension, etc.

I thought about transplanting a 617 into a 420SEL that was for sale but figured it would be too much trouble.

There is a guy who transplanted a 617 into a '73 450SEL so it can be done... It is currently on ebay. Maybe you can email him to see how he did it.

Overall I doubt it'd be THAT big of a hastle, I'd probably go for it if I found a mint one with a dead engine as you described.....my car has body issues, and I am on the prowl for such a vehicle....though up here in MI its essentially not going to happen, when my car gets worse I'll probably expand my search area. :D (I fight the rust every year though, so thats a looong ways off)

I don't understand why you would hack up a car like that...

If you want to know what parts interchange start looking at the EPC. Short of diving in that's the only way to know.

560SEL gets 15mpg, SD gets 25 or so. Diesel is more expensive. Add in the cost of finding the necessary parts, the time and hassle involved and you would need to drive forever to recoup the costs. And it would take time as the car would be a dog.

You could also tweak the diesel for a little extra power (intercool it etc...) and also I doubt it'd be noticably slower than a 300SD. Maybe a little off the line due to the 2.47 diff, but it'd also be limited slip, so much better traction and lower freeway rev's.

The 560 is a very maintenance needy engine, if not so much the engine itself as the systems that run it. Fuel pump, relays, K-Jetronic injection system/computer....all very expensive stuff that can break. A 603 or 617 will run much longer with a lot less maintenance and cost. Also, I highly doubt a 560 averages 15mpg.....more like 11-12. On Premium

I disagree with the last poster. But having a second complete car to do the swap is almost essential.

When done you would have a very nice car with options never offered in a diesel, and last time I looked the diesel cars of that era command strong prices and the v8s even with good motors are very tough to sell.

Tom W

Every MB I have seen in the junk yard or at the side of the road etc around here is a gasser.....and I've known people personally with older gasser ones that loathed the fuel/electronics issues they had with them. Thats what I am basing the reliability issues on....I don't doubt a MB V8 will easily last as long as the diesels....I merely question the $$$ needed to accomplish it....I am 99% sure it'd be more.

I have seen a 380SEL that had 420k on it still running fine....and a 560 with nearly 300k......so they do last a long time, they just seem to get scrapped easier than the diesels.

Also, as a side note, if I had the opportunity to find a nice MB v8 (or even a 6cyl....) vehicle I'd snatch it up. :D ;) In fact I am going to look at a fairly nice '93 190E 2.6 sometime in the next couple days if the seller gets back with me... :D

Small block chevy and a turbo 400.

There is one on the board here in a 300cd

Getting away with murder.
 

I know I guy who did exactly the REVERSE of that. He showed me the W126 "Diesel" 560 sedan he had, just Friday.

He has a ultra high line tuning shop (Maseratis, Ferraris, Aston Martin, Porsche, Brabus, Kleeman, etc.) but has owned and still does own W126 cars too.

He's in California, which has ultra strict emissions laws, with huge fines and penalties (including changing it back to stock, regardless of cost) for violators that get caught, especially for visual modifications to smog equipment..


But, in California, all Diesels are TOTALLY exempt from Smog checks. That means his diesel W126, with its wildly modded 560 engine, and Diesel VIN#, is still known to the Smog check people as a Diesel vehicle, and it is total immune from ever being checked visually or on the dyno for emissions.

But I'm quite sure he knew absolutely NOTHING..:D... about that when he went and stuck the gasser engine in there.

Mua hahahahahahahahahaha!!!!!:D

Putting a diesel in there? It has been done. (Canada)
 

And a couple of other times too. It is not easy, or cheap. But it can be done.

But - even with today's high prices - you'd have to use up a LOT of gas to even approach the cost of a conversion, so it is is not really worth the time or trouble, if dollar per mile running cost counts...



"ICEMAN" - up your way - in Canada, who posts here now and then, has done this in Canada, successfuly, with a W126 coupe.

So it can be done. You should search for his posts about it.

There was a forum exhange about it, that I recall went like this:

~~~"Put a diesel engine in a 560SEC? Who would want to do a thing like that?"


~~~"Yeah, that would be like cutting off its balls!!"


~~~"I know EXACTLY what you mean. My wife already did that to me!!"


:D:D:D:D:D

I'll have to go see this 560 ...
 

Thanks for the advice on this guys.

I found the vehicle through a Craigslist posting looking for some seat parts. The story could be true or complete BS - body in good shape, mint interior leather seats, busted in-op engine, belonged to Dad who died a couple of years ago - has sat in garage.

They proposed $800 (I know!!). I figure if the body is in good shape it's worth that for the seats/wheels/window parts alone. This is the season to pick up a donor diesel with a good powertrain that just got smashed in the snow and ice .....

I'll probably show up and find it's a junker .......

go for it! I can't understand why previous posters would argue the economics of an engine swap. IMHO its done for the 'cool and unique' factor. Personally I'd try to find a 560 SEC... I'm in love w/ that coupe body style, have been ever since the mid 80's when I saw my first 500sec.

The beauty of the coupe is unquestionable but sometimes you just need four doors!

Tom W

Now that's an interesting point I never even thought of and CT is essentially the same in that aspect. Hmmmm...I've got all kinds of crazy ideas running through my head now! :D