MB conversion

[svenakela]

Sorry for writing in English. My German is not good enough for this topic.

I am going to renovate an LT from 1980 and the old diesel engine is for sure replaced. Considering the option, it would be nice with some opinions on my ideas. I have a lot of experience and knowledge in VW diesels but I'm not really sure which way to go this time.

My options.
D24TIC. The easiest option but still old and it is a lump. I can source one pretty easy and spare parts for a renovation is easy to find too.
Still, it's an old slow engine.

TDI R5 2.5. I can source this engine somewhat easy, but if I go with this engine I need another drive line. I was actually contemplating buying a newer LT and take everything (engine, gearbox, rear axle). Big minus is all the space needed for two vehicles at the same time and all the extra work to get rid of it.

1.9 TDI. I know these engines in and out. But they don't fit the LT gearbox without adapter or mods. And there is no good alternative if I want to change gearbox and the original transmission is way too low for a TDI. Also I'm worried this engine will work harder than healthy with it's smaller volume. Even though there are 165 hp versions they are not really made for high torque output in the long run (like moving a gigantic shoe box on wheels on Autobahn...)

And here comes my joker, which I start to like quite a lot:
OM60x. Yes, an MB engine. The OM603/OM606 and OM605 are very reliable engines and tuners use them with untouched internals with very high output. Also, the OM603 and OM605 exist with mechanical pumps that makes a conversion super easy. They are used in rear wheel drive applications and there are some beefy gearboxes too and I think the transmission taken directly from an MB car will survive a long time in an LT, they are also very reliable. I can source both engine and gearbox pretty easy, there are many MB's in Sweden.
As a bonus, if I brake down somewhere in south Europe there shouldn't be a problem to find a replacement gearbox or engine.
3 litre MB, will I be killed by fanatics for not using a VW engine?

Please, give me your thoughts! :)

[Skoot]

OM603 sounds like a good plan. I have no idea now how big modifications will be needed to put it in a LT but the engine itself is very good choice!!

[svenakela]

Modification is not a problem, that's a part of the challenge. :)
Yes, it seems like the OM-series is a very good choice.
Also, according to reliable sources the Volvo M90 gearbox should be strong enough to pull an LT around. With that in mind the D5252T/M90 combo is a choice too. Still, the OM is a favourite.

[Butze]

I would be very happy to see pictures of that conversion.

I drove W124 300D and it is my favorite engine, even a TD is a "beast" (do not compare to TDI)

I guess it will be difficult because the OM is much longer than a LT engine. Anyway you have my green light to do so ;) Looking foreward to your conversion blog.

Regards, Thomas (did you found the TDI 5 conversion in turkey? it is very smart)

[svenakela]

Green light is good. :)
Yes, I've seen Rene's 2.5 TDI conversion. I want to bring up the gearbox to par as well, and with an OM it's easy to find a very sturdy gearbox (like a 6 speed 716.65x).

[svenakela]

Continuing my own thread with the latest thoughts. I have sourced a few OM606 and 603, both are six cylinder but DOHC vs SOHC. They are somewhat pricey as they are popular among tuners. Considering the gearbox I need to buy as well and the length of the engine, I have been looking for a OM605 too. It's the five cylinder 2,5 l version and it is more or less the same engine as the 606 but one cylinder short. They are also known to perform very well and as I'm not looking for a monster HP machine but a reliable engine with a good amount of torque, these are good options too.
I was aiming for an year 2000-ish six speed gearbox for the 606. It turns out I can buy a running car with an OM605.690 (turbo intercooler) and get a good manual five speed gearbox at the same time for the same amount of money as a 606 engine. The OM606 was never built with manual transmissions so I have to source a gearbox anyway if I buy a complete six cylinder car.

Considering my options, I might end up with a five cylinder.

[Skoot]

5-cylinder sounds like an option. But in that case why not think about a drivetrain from LT2 or Sprinter? Or is it no option to have a electronic controlled engine?

[Philip86]

That's a very interesting topic ;)
An engine swap to a Mercedes engine could be a good and especially a reliable solution.
Personally a 6-zylinder would be my preferred choice, but i think it's too big for the LT's engine bay and ther's also the gearbox-issue.
I had a quick look throw the web (wikipedia mainly ;)) und found a few possibilities:

1)OM 605.960 from the C 250 Turbodiesel (W/S 202) / 110 kW (150 PS) bei 4400 / 280 Nm bei 1800
2)OM 602.980 from the Mercedes Sprinter (W 901–905) / 90 kW (122 PS) bei 3800 / 280 Nm bei 2000–2300
3)OM 612.981 from the Merceds Sprinter (W 901–905) / 115 kW (156 PS) bei 3800 / 330 Nm bei 1400–2400 this one is quite modern choice with CDI-technology, maybe a litte bit too modern for our old cars?

Does someone know about an already done conversation to a mercedes-engine?

kind regards Philip

[erazer13]

2,5tdi 5-cylinder http://www.vw-lt-karmann.de/html/umbau_auf_2-5_tdi.html

[svenakela]

That's a very interesting topic ;)
An engine swap to a Mercedes engine could be a good and especially a reliable solution.
Personally a 6-zylinder would be my preferred choice, but i think it's too big for the LT's engine bay and ther's also the gearbox-issue.
I had a quick look throw the web (wikipedia mainly ;)) und found a few possibilities:

1)OM 605.960 from the C 250 Turbodiesel (W/S 202) / 110 kW (150 PS) bei 4400 / 280 Nm bei 1800
2)OM 602.980 from the Mercedes Sprinter (W 901–905) / 90 kW (122 PS) bei 3800 / 280 Nm bei 2000–2300
3)OM 612.981 from the Merceds Sprinter (W 901–905) / 115 kW (156 PS) bei 3800 / 330 Nm bei 1400–2400 this one is quite modern choice with CDI-technology, maybe a litte bit too modern for our old cars?

Does someone know about an already done conversation to a mercedes-engine?

kind regards Philip

As far as I know I haven't found an MB-hybrid, but you never know what lurks in the forests... :)
I know many people moving newer engines to MB-buses and campers, but that's a totally different story. I think a six cylinder should fit. Tight yes, but it should work and if it doesn't fit I'll make it fit. The 602.980 is considered being one of the most reliable diesel engines ever built and five cylinder machines are more or less the six cyl block with one piston cut off. It's for sure a very good option. They have heavy blocks and every cylinder is surrounded by bolts in a circle, the head can not move or warp. They have twice as many head bolts compared to a VW diesel. Only problem with the 602.980 is that most of them comes from Sprinters and they have many miles on the odometer. I haven't decided yet, I am waiting for the perfect donor object but at the moment I tend to go for a five cylinder. I have a perfect donor car for a very good price but it is far away.

@erazer13, thank you for the link!