Gas to Diesel conversion

[MBNRA]

using a 1983 300D Turbo engine. Anyone done it? I like the SL, but I want a Turbodiesel in it and am looking for one with a good body and interior with a blown motor.

[Roncallo]

Originally Posted by MBNRA

using a 1983 300D Turbo engine. Anyone done it? I like the SL, but I want a Turbodiesel in it and am looking for one with a good body and interior with a blown motor.

Ive been thinking about it but I wouldn't wast my time with a 83 engine. the later 6 cyl, sorry it's been a long time I don't remember the engine codes, had a halfway reasonable level of power. But if I were going to pull this off I would be looking into a newer Blue Tech engine.

[MBNRA]

Originally Posted by Roncallo

Ive been thinking about it but I wouldn't wast my time with a 83 engine. the later 6 cyl, sorry it's been a long time I don't remember the engine codes, had a halfway reasonable level of power. But if I were going to pull this off I would be looking into a newer Blue Tech engine.

But the 617.95 engine is so dependable though! I'm not sure there is enough room for an inline 6 under there. The 1983 617.95 I have access to is a 5 cylinder turbo diesel engine. These are all cast iron and hard to destroy!

[jdc1244]

That will be a slow SL – don’t get me wrong: I had a 300 D that I loved to death, the engine was perfect at over 410,000 miles. But did you examine the SL’s engine bay to see if it will accept the 617? You’ll need the transmission as well. Will the mounts match and the pan clear the cross member? Anything can be done for a price but gas to diesel is a major undertaking.

[wilsonw116]

A friend of mine did it to his 500sl euro. It goes pretty good and is something you don't see everyday.

[MBNRA]

I kinda figured I would have to get a tranny that fits a 617.95 Turbodiesel. But my 300D is really not that slow if you tune them right and mine will actually peel a little rubber if you punch it from a standing stop! Here's what I have found out so far:
*You will need a 300d tranny, but it will fit the driveline and tranny mounts along with the necessary linkage ok. Don't toss your 300D parts car until your done!

*Engine will fit in the engine bay, but one engine shock absorber mount will have to be fabricated with a welder because the engine shocks are different between the Gas and the Diesel. The other shock lines up no problem.

* The 617.95 Diesel will NOT clear the hood, so some modification here will be necessary, either to the subframe to drop the motor an inch or so or the hood cut and modified with a hood scoop! But I could live with this since there are some really cool looking hood scoops out there and I don't really need a high profile one! I like this idea better than cutting into the subframe since this directly affects the cars handling and stability!

* Modifying the wiring harness to accept a glow plug relay is not to difficult, just take the Ignition hot lead and send that to the glow plug relay and that should do the trick.

* Stopping the motor is less clear and I think i would also have to swap the Ignition switch from the 300D to the SL or put in an engine stop switch/solenoid that functions like a switchover valve supplying vacuum to the fuel shut off device on the Diesel IP.

I've talked to some who know someone who did do this, but have yet to really talk to anyone that did it themselves! This is a big difference! Just looking for that gearhead whacko who has too much time on his hands! I would think the fuel economy would be great since I get 30 MPG on my 300D that I'll be keeping!

[MBNRA]

Originally Posted by wilsonw116

A friend of mine did it to his 500sl euro. It goes pretty good and is something you don't see everyday.

I also happen to be in Arizona! I live just outside of Phoenix! I'd love to see your friends car if it's at all possible someday!

[cth350]

Don't do a scoop. I'm sitting in the middle of this conversion and it looks like small spacers in the subframe mount to take up half the space and perhaps a notch cut in the subframe for the other half is the way to go. The notched out part will need to be rewelded back in for stability, but it's a lot easier and looks a heck of a lot nicer than a scoop.

-CTH

[MBNRA]

Originally Posted by cth350

Don't do a scoop. I'm sitting in the middle of this conversion and it looks like small spacers in the subframe mount to take up half the space and perhaps a notch cut in the subframe for the other half is the way to go. The notched out part will need to be rewelded back in for stability, but it's a lot easier and looks a heck of a lot nicer than a scoop.

-CTH

Cool! Do you have pics you could post of this operation? I'll bet those would get a lot of traffic!

[wilsonw116]

He lives in Tucson. As far as I can remember he didn't modify the hood and he made it sound like it was a fairly straight forward swap. He made it sound easy but then again he's quite good at this type of thing.THe car looks stock on the outside and the 5 cylinder turbo fits well. One of the things he mentioned was fabricating the mounting for the oil filter. He also added dash mounted boost control knob. The guy is a bit eccentric and doesn't always welcome visitors.

[MBNRA]

OK, OK, it may be tacky to even think of putting a hood scoop on a Mercedes Benz, but what about some of these? I kinda like the Blue one and they all could be pepainted any color! It sounds as if the cutting and rewelding of the subframe is a lot more work than fitting a nice looking low profile scoop. The first one is a steel scoop and the rest are fiberglass.

[Roncallo]

Originally Posted by MBNRA

OK, OK, it may be tacky to even think of putting a hood scoop on a Mercedes Benz, but what about some of these? I kinda like the Blue one and they all could be pepainted any color! It sounds as if the cutting and rewelding of the subframe is a lot more work than fitting a nice looking low profile scoop. The first one is a steel scoop and the rest are fiberglass.

My opinion is that the hood line of the 107 is perfect. Hold the hood line at all cost or else just just buy a diesel powered pickup truck.

[Roncallo]

Originally Posted by cth350

Don't do a scoop. I'm sitting in the middle of this conversion and it looks like small spacers in the subframe mount to take up half the space and perhaps a notch cut in the subframe for the other half is the way to go. The notched out part will need to be rewelded back in for stability, but it's a lot easier and looks a heck of a lot nicer than a scoop.

-CTH

CTH

I'd love to see this car. I do travel to LI occasionally.

[Roncallo]

Originally Posted by MBNRA

But the 617.95 engine is so dependable though! I'm not sure there is enough room for an inline 6 under there. The 1983 617.95 I have access to is a 5 cylinder turbo diesel engine. These are all cast iron and hard to destroy!

You will find as you do this that the engine and trans are just a fraction of the cost involved, at least if you plan on doing anything to a factory like finish. So far I'm up to about $15K parts + $5K in tools and that's AFTER I purchased the engine, trans and rear end. The V12 may seem complex but the installation parts cost wont change much. And certainly a lesser quality install could have been done for less than 1/2 that.

Making the decision to swap an engine because you have one is generally not a good idea, unless the engine you happen to have is something like a 426 Hemi.

[cherry_560SEL]

It would be nice to see some pics of your engine install