I am dreaming of doing the same conversion.
Was, without any technical insight, thinking maybe to a 3.6 from mercedes.

 

You can put almost any engine in there.

The vertical M110 2.8lt inline-6, the slanted 2.6lt, 3lt M103, or 2.8lt, 3.2 lt or even 3.6lt M104 inline-6, the M112 V6, the M113 V8 and the M117 V8 all were used in the G-Wagen. Hell, I wouldn't be surprised to find a few with even the M120 V12 in there!

The closest relative to the M102 2.3lt would be the M102 2.3lt 16 valve from the 190E. It would have almost as much torque and even more power than the M110 2.8lt or M103 3.0lt 6-cyl, minus the mass penalty. And you might even be able to use the existing engine mounts.

 

Thanks for the answers guys! We have a new information from today, we lift the car and investigate under it... so, the transmission is not older one, now in the car is 722.4 transmission and i think this is good and will be more easier to put m104 engine for example, but we must learn how first, because we have 70 sm from transmission to radiator, 6cyl engine need around 85-90sm... i think we cannot move the transmission, we must put it inside, but there is not space...

 

I am totally ignorant in this, can someone explain me...
I always though that each engine has its own transmission. then probably few engines can all run on the same transmission, and few transmissions could all run on the same engine. provided this statement is true, is there any compatibility chart through the Mercedes different models?

 

Yeah, for example i was owned S320 CDI 2000 year, and this car was working with 722.6 transmission. Now i have E250 Diesel, from 1997 and this car also working with 722.6 engine... and a lot of another engines worked with this transmission, also called 5G tronic. In the past i was owned a 1993 w140 S320, 231hp with m104 engine and this car has 722.3 transmission, also a lot of the engines and cars producted in this years also worked with 722.3 transmission. Now i seen on my G-class 722.4 transmission... i know this transmission is not very strong and powerfull, but i think can work good with engine of 200-250hp maximum.... so i think to try a 4cyl engine for the G-class. I think for 230 kompressor or 200 kompressor, but with another turbo, not the original compressor, because will be hard to put in under the hood... what do you think about this configuration? m111, 2.3 kompressor must be fit good on the position of the old 2.3 engine without any problems and work with 722.4 transmission without any problems? Some advices?

 

If you are bumping up the power, I would suggest also switching to the 722.6. This gives you an overdrive 5th gear, meaning that that new engine of yours will not be thrashing itself to death at speed. Stand-alone transmission controllers are available.

 

I think the easiest swap, with the most power, would be a 3.6L M104 from a C36 AMG. You'd get ~270 HP, and you could keep your existing 722.4 transmission. Don't worry about the RPMs being high, these engines handle high RPMs very well, so does the transmission. A 722.6 swap would be pretty complicated, and would require a stand-alone transmission control module. But if the overdrive gear is really needed, you can get a 722.5 transmission, which is just a 722.4 with an electric overdrive. I know the W140 had a 722.5, I don't know which other chassis. If you have trouble finding a 3.6L engine, you could use a 3.2L. Of course though, a lot of other engines would probably fit in there.

 

Yeah i want to put 3.2 engine too, it's easy to find it and easy to support it after this, but there is no space for it. I seen today the space between the gearbox and the front radiator are 70 sm total. We get the sizes from 2.6 6cyl engine and the size for the engine are 85sm. We need 15 santimeters more... will be very hard to do this and the only one easiest way is to put 4cyl engine...

 

Well I think all you would need to replace is the fan shroud, not the actual radiator. Replacing the fan shroud with a shroud made for the 6 cylinder engine will give you the room you need

 

Just change the rear bracket, and shorten the prop shaft. Those aren't too expensive to do. Then the inline-6 will fit, as it was designed to.

 

Yeah, but there is not fan shroud... look the pictures

I think the only one way to put 6cyl engine is to move the transmission back, and we need to move 15-20 santimeters... this is will be expensive and hard... may be the way is 4cyl engine with turbo...

 

Time to find a shroud. Without it you will have overheating problems.

 

Have found a G 300 diesel in decent conditions almost no rust, and is cabrio!
Price is really good also because it is missing the engine..
So need to take a quick decision, shall I get it? The idea was to replace the engine anyways so the fact that it's missing it is actually a good thing so I can get an even better deal. Now I want to put an engine that will work with almost no electronic also because the car has zero electronic in it. What are the options? Was thinking to buy another Mercedes from the graveyards and use engine transmission and gearbox.