Om606
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rob1miles
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https://en.wikipedia.org/wiki/Mercedes-Benz_OM606_engine
I'm not sure about the 606, I'm more familiar with the 603, but for the 603 all the turbo engines were LHD.as the steering box is where the turbo would be.
Wonderful engine, good for 400k miles, sooth, quiet, just useless off-road, torque curve is all wrong.
I'm not sure about the 606, I'm more familiar with the 603, but for the 603 all the turbo engines were LHD.as the steering box is where the turbo would be.
Wonderful engine, good for 400k miles, sooth, quiet, just useless off-road, torque curve is all wrong.
Tall Ratbag
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OM606 engines are very good engines, BUT, they are engineered for car use,and as Rob says, no good off-road.
So,the question you need to ask is; do you want to use car on-road, or, off-road?
The difference is (largely) the shape of the torque curve. For good off-road (and commercial) use, an engine with a torque peak at low rpm,and a falling torque characteristic is good. As the engine bogs down, the torque rises,which gives a happy situation; an equilibrium can be found.
An engine designed for a passenger car (like the OM60x engines) has the peak torque at higher engine speeds. So, as the engine bogs down, the torque falls - disastrous off-road - you need to grab for a lower gear,just when you don't want to.
If you do want to go off-road, then you would be far better looking at an engine from a Mercedes Sprinter. As the engine will be designed for commercial use, it willhave a torque curve better suited to off-road use.
If you do choose an OM606;
- beware inlet valve recession. The engines are so smooth it's difficult to diagnose. A very slight knock from the affected cylinder (usually 5 or 6, at the back of the engine), and smoke blowing back from the inlet ports if you run the engine with the inlet manifild off
- consider the control of the engine. In the W124, the pump is controlled by a cable,and shut off via vacuum* In the early W210, the pump is a fly by wire,so you'll need to wiring, potentiometer from pedal, and the ECU.
- fit a new set of fuel pipe O rings as a matter of course when you fit the engine. These go brittle and let air in,causing all manner of bad runnig and starting problems.
- Sadly, these engines are favourites amonst those who use comedy fuels obtained from the yard behind the local chippy.
* For the W124 units,you need to apply vacuum to stop the engine - so,a failure of the vacuum system means the engine can't be stopped - so,you need to use the fuel filter which has a tap fitted on top to stop the engine. Don't be tempted to leave that out!
So,the question you need to ask is; do you want to use car on-road, or, off-road?
The difference is (largely) the shape of the torque curve. For good off-road (and commercial) use, an engine with a torque peak at low rpm,and a falling torque characteristic is good. As the engine bogs down, the torque rises,which gives a happy situation; an equilibrium can be found.
An engine designed for a passenger car (like the OM60x engines) has the peak torque at higher engine speeds. So, as the engine bogs down, the torque falls - disastrous off-road - you need to grab for a lower gear,just when you don't want to.
If you do want to go off-road, then you would be far better looking at an engine from a Mercedes Sprinter. As the engine will be designed for commercial use, it willhave a torque curve better suited to off-road use.
If you do choose an OM606;
- beware inlet valve recession. The engines are so smooth it's difficult to diagnose. A very slight knock from the affected cylinder (usually 5 or 6, at the back of the engine), and smoke blowing back from the inlet ports if you run the engine with the inlet manifild off
- consider the control of the engine. In the W124, the pump is controlled by a cable,and shut off via vacuum* In the early W210, the pump is a fly by wire,so you'll need to wiring, potentiometer from pedal, and the ECU.
- fit a new set of fuel pipe O rings as a matter of course when you fit the engine. These go brittle and let air in,causing all manner of bad runnig and starting problems.
- Sadly, these engines are favourites amonst those who use comedy fuels obtained from the yard behind the local chippy.
* For the W124 units,you need to apply vacuum to stop the engine - so,a failure of the vacuum system means the engine can't be stopped - so,you need to use the fuel filter which has a tap fitted on top to stop the engine. Don't be tempted to leave that out!
Right so the 6bt then does anyone know the cons with that? Tuns of low down torque ect. I have read put your foot down in 1st 2nd break things ? Anyone one know if that's true or that people heard someone say this ect. If true what's it breaking? Or do they mean if you try to rev the nuts off it in 1st 2nd it breaks something , but what's the something?
Last edited:
rob1miles
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Ratbag, your post made me smile with recognition. I did 100k miles in a W124 and it would bog down something rotten, it had the 4sp auto and clearly needed 5 sp. On the hill on the M40 if I hit the start at 70 I'd be at 60 at the top, if I hit the start at 65 I'd be down to 30 by the top! It was impossible to get down the gears fast enough to recover the speed. And the vacuum stop broke and I had to open the bonnet and get to the manual shut off UNDER the inlet manifold. And all the fuel o rings failed. Loved that engine, it was so smooth, fantastic motorway burner. I used to drive London to Liverpool, I timed the journey in a 320 hp 500 SL and the 100hp W124 diesel, 15 minutes difference over 220 miles because the w124 sat at 75 all the way. But interesting, the W124 did 35 mpg and the 500 SL did 25. In traffic the 124 would still be 35 but the SL about 15 but at 70 they were much closer.
6BT - NO, old. very big, very heavy. I've been in discussion (via youtube) with a guy who fits 6BTs in Chevy Pickups, he's stopped using them, old hat now. Look at the conversions and look for the black smoke, that's not UK MOT freindly.. If you want a 6BT then you need to buy a vehicle that has the space and suspension to carry it. There's a Discovery with a ^BT on youtube, its a huge amount of work, noisy, smoky and last time I watched they still hadn't been able to get the bonnet over the engine. I recon if you really really hate the LR engine and so love the rest of the LR vehicles that you can only live with a mongrel of LR truck/an-other engine then the way to go is Iveco as there are a lot of very strong engines coming up as vans are getting scrapped..
6BT - NO, old. very big, very heavy. I've been in discussion (via youtube) with a guy who fits 6BTs in Chevy Pickups, he's stopped using them, old hat now. Look at the conversions and look for the black smoke, that's not UK MOT freindly.. If you want a 6BT then you need to buy a vehicle that has the space and suspension to carry it. There's a Discovery with a ^BT on youtube, its a huge amount of work, noisy, smoky and last time I watched they still hadn't been able to get the bonnet over the engine. I recon if you really really hate the LR engine and so love the rest of the LR vehicles that you can only live with a mongrel of LR truck/an-other engine then the way to go is Iveco as there are a lot of very strong engines coming up as vans are getting scrapped..
Half shafts would be first i think. There was recentlyish a very good build in the disco section which may give you some ideas
OK wasnt in the disco section
https://www.landyzone.co.uk/land-rover/discovery-1-v8-cummins-6bt-conversion.324787/
https://www.landyzone.co.uk/land-rover/discovery-1-v8-cummins-6bt-conversion.324787/
