917 OM366A swap for newer?

[Kveite]

Hi,
I hope it’s okay to post in English here I have a MB 917 with a OM366A engine. I have seen them upgraded to OM366LA for more power and then change for the high speed axles for increasing the speed, but is there a different way? Is it easy enough to swap for a newer OM900 series engine for power and lower fuel consumption? Is it at all an idea to look for higher revving engines like a Duramax to get speed “the easy way” or am I far off as the torque figures are not usable for a higher revving engine and it probably wouldn’t work very well?

My 917 is built as an 4x4 Overlander that weighs in around 7tons as configured. I don’t know the axle codes, but it likes 80km/h and 90km/h seems to be pushing it

Not sure if engine swaps are common on these and how easy it would be to adopt a new engine to the configuration.

Best Regards,
Lasse

[Wilmaaa]

Hi Lasse,

it's totally fine to write in English, but the answers might not come as quickly as usual. Or some people might answer in German

Just have some patience

[Kveite]

Thank you for the reply. I do want to add that I know the main difference between the size, weight and build quality between a transport truck’s engine and a smaller lighter personal truck engine. But as my 917 will be used as anOverlander truck I do not need the 1 million km rebuild intervals even though it is a plus Also there may not be a huge difference in the rpms, but I do believe a duramax, Cummins or similar may be easier to tune for a little bit higher rpms that again solves the max speed - or am I completely off tracks?

I hope to get some insight as I’m sure swapping the OM 366 with something else must have came accross somebody else’s mind before. Not that it’s a bad engine.. Perhaps the clutch gearbox input shaft combo is not very adoptable for other setups.. I have the integrated 4x4 gearbox in mine, but I have heard there’s an external transfer box that works with a regular 2wd gearbox, if the gearbox needs to be swapped with the engine.

Please feel free to answer in German as google translate is my friend, and often a funny one

[DäddyHärry]

Hi Kveite, the LA has bigger Motor housing, because of the intercooLer...
so i read in one of the cabin-swap Threads
4 Motortunnel...
Regards Härry

[siegerland]

Hi Kveite,

some comments from my side.

Is it easy enough to swap for a newer OM900 series engine for power and lower fuel consumption? Is it at all an idea to look for higher revving engines like a Duramax to get speed “the easy way” or am I far off as the torque figures are not usable for a higher revving engine and it probably wouldn’t work very well?

Since the OM906 both and the OM904 where on board of the late LN2s replacing the OM366LA it should be possible theoretically, no idea how much hours would be necessary but if you do not do it yourselves it probably would cost a couple of thousands of Euros + the engine itself.
Additionally it would be necessary to adjust the cabin engine tunnel, since the intercooler respectively the turbo-hoses ask for more clearance.

I don’t know the axle codes

You may post the VIN of your truck, some have access to Mercedes-Benz' works data and are able to detect the type of axles and the transmission ratio. The VIN is on your car papers starting with WDB6... and has total 17 digits if I am not mistaken

Not sure if engine swaps are common on these and how easy it would be to adopt a new engine to the configuration.

quite some work to do

I hope to get some insight as I’m sure swapping the OM 366 with something else must have came accross somebody else’s mind before. Not that it’s a bad engine.. Perhaps the clutch gearbox input shaft combo is not very adoptable for other setups.. I have the integrated 4x4 gearbox in mine, but I have heard there’s an external transfer box that works with a regular 2wd gearbox, if the gearbox needs to be swapped with the engine.

Changing the engine or giving the existing engine more power respectively more torque does not make the vehicle automatically faster, since the total high end speed is limited by the total transmission ratio which results from 4 factors:

• gear box respectively the applied gear _click_
• the transfer case
• the axle transmission ratio --> modifying would be challenging and expensive too
• the wheele size

So, you have a couple of options to follow different targets. Some have changed the main gear box, some have modified the axles transmission ratio some have have tires with higher circumference. Ohters have a combination and/or additionally a tuned engine

What would be your targets?

• Higher end speed respecitvely lower revolution level? --> one idea would be to change gear box towards the GV4 65 6/9,0 it is a kind of 12-speed gear box highest gear is translated 0,83 --> _click_
• More torque to hold speed rising dunes and mountains? --> tuning the injection pump and related measurements and/or mounting an intercooler --> _click_

By the way, we like pictures, would you like to post someones of your truck? And, where are you from?

Greetings

Stefan

[Pirx]

Is it easy enough to swap for a newer OM900 series engine for power and lower fuel consumption?

This engine won't solve the speed issue, as it works at lower rpm.

Furthermore, if I remember some discussions in Unimog-boards correctly, it is not a good idea to swap a OM366 engine with a OM904/906 engine. These engines have an electronical motor management. It may not be impossible, but bringing this sytem to live after a swap into an "old" vehice will take at least a lot of time, money and health. Always presumed, you have access to the original Mercedes-Benz electronic testing device and software.

Pirx

[Kveite]

Thank you for the extensive replies. I must say that this vehicle is not yet at hand, but is in the process of being purchased/handed over - in respect of the seller.

The VIN is WDB6761421K363682
It would be interesting to have it decoded if anyone can

Also tried to attach a photo. Hope it shows..

The goal for these thoughts would be more torque, possibly less consumption and most importantly higher top speed. Changing the engine might solve all three if a newer stronger more efficient engine got in and if it had a higher rpm range let’s say about a 1000rpms more, there’s the higher top speed without changing any later exchanges in gearing. From the current replies I think the most sensible way would be long term to change the gearbox and short term give the engine a tune and intercooler.

[siegerland]

gear box:
Mercedes-Benz
TRANSMISSION, MANUAL SHIFT
715.031 => G 3/55-6/8,5
6-Speed

engine:
Mercedes-Benz OM 357.906
DIESELMOTOR,125 KW (170 PS),MIT AUFLADUNG,LADELUFTKUEHLUNG,
EURO II
357.906 => OM 366 LA !
You are lucky, intercooler already aboard!

[Kveite]

Thank you siegerland!

Good data to know of for sure. I knew it was a 170hp unit, but I thought it was only the 220 and 240hp units that was a LA with intercoller. That makes it a lot easier for the power upgrade at least. Does anyone know what would separate this one for a 240hp unit or if there is a recommended way of tuning it? Pump needs to be redone and perhaps nozzles are different?

[siegerland]

Hello Kveite,

[...] but I thought it was only the 220 and 240hp units that was a LA with intercooler.

to meet EURO-II requirements the latest OM366 had turbo-charger both and intercooler

Does anyone know what would separate this one for a 240hp unit or if there is a recommended way of tuning it? Pump needs to be redone and perhaps nozzles are different?

Generally speaking the (O)M366 is listed in the EPC in 16 categories (different truck categories/industry/domestic both an foreign markets/LPG/...) with total 327 ! designs (German: Baumuster).

What separates the 156 HP, the 170 HP from the 211 HP or 240 HP type varies gradually over many designs, and years. I think few people oversee design changes completey since the Merc-Guys have retired or passed away. Of course you know that the mode of functioning of thermal engines means to optimize the engine itself as well as its environmental components. Harvesting more power from one and the same basic engine implicates that additional heat needs to be taken away (to finally ventilate to the air).

The strongest permorming OM366 can have either:

• a bigger oil pan

  

  oil pans with different capacity

• a bigger water cooler or other grid designs
• another fan wheel with either simply more wings or a different wing design
• different pistons
• a different internal set-up of the diesel injection pump
• different injector nozzles

  

  injection nozzles applied to OM366

• different turbo-chargers (geometry of compressor blade wheel / turbine wheel), with or wihout wastegate

or mostly a mixture of it.

The gentleman I had the pleasure to learn from all the above listed contributions told me that novels could be written on this topic. Allegedly there were 300bar EURO-III test version for USA, no idea if that arrived @ production stage

I think some BOSCH-Services know how to tune the injection pumps and pimp the engines. I have no reference. To simply adjust only one feature of the engine-system could mean to have even less power, it is the sum of many and the right measurements which make it work more performing in what direction ever.

I am a learner too and just share what I have soaked up so far.

So no guarantee on accuracy both and completeness

Stefan