Mercedes-Benz Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 ·
Hi guys,

You might remember I have a LAF1113B with a OM352A in it.
I'd REALLY like to get the engine revs down a bit, with my 1:1 gearing, 1:5.715 axles and 385/65R22.5 tyres I get 2,912rev/min at 100km/h (62,14mph).

So after a fair bit of research I found the G56-6 gearbox used in Atego and Vario with a 1:0.786 ratio in 6th, WUHUU!
I'd need to source an SAE bellhousing for the OM352A though, a custom clutch job, new mounts, new prop shaft (LAF1113B is running a divorced T/C), but doable, and would lower my revs to 2,289 at 100kmh.

Well, I'd like a newer turbo too, and an intercooler, probably bump the pump a bit, maybe see if I can get a better coolant flow like the OM366LA (Maybe a OM366LA) I think you get the picture...

That got me thinking....

(And a detour: Several years ago I had a VOlvo TGB1314, you know, the Unimogs distant Swedish cousin, portal axles and a bit retarded, especially since it comes with a detuned Volvo B30, no torque, lots of gas, always carb issues) that I put a Toyota 1KZ-T in. My philosofy was to haveas few custom made parts as possible, so the Volvo gearbox and T/C went with the B30, so the only custom mechanical parts was the drive shafts, meaning anything engine/gearbox/T/C related patrs was of-the-shelf Toyota parts, so breakdowns would be easy to fix anywhere)

Why not install the complete OM904LA+G56-6 driveline in the LAF1113B? A complete package meant to be together, and serviceable at a standard truck shop.
Sure, I'll have my hands full, it's a much more electronically governed engine, I'll need the ECU, the VCU, an assortment of misc. parts, electronic speeder pedal, etc. or use a standalone ECU to get it going, and going from a 5.7L R6 to a 4.25L R4 doesn't sound too sexy, but look here:
OM352AOM904LA
HP168hp177hp
Torque461nm/340lb/ft675nm/498lb/ft
Weight460kg/1,014lbs400kg/882lbs

Nevermind the HP increae, the torque goes up 46%, that's not bad, while overall weight goes down.
So why not look at the OM906, well, I have to save weight wherever I can. And the additional power will create further problems downstream, T/c, axles etc. And going to a shorter engine makes fitting an intercooler and perhaps a condenser much easier.
And the OM904LA is cheap to buy, like €2,000 and up, so (being optimistic here), not far from the cost of upgrading turbo, intercooler, piping, cooling etc. on the OM352...

My main issue though, is that it is almost impossible to find data on the OM904LA, can I take a 130hp, and use the 180hp ECU to get 180? Are there improvements over the years? Does EGR come a certain year and should be avoided? Where is the immobilizer? (which I'd love to have!!!), do I need to flash eproms etc?

Please give your opinion, informed or otherwise!
 

·
Registered
U500 with Unicat camper
Joined
·
949 Posts
The ON924LA is dimensionally identical; 218hp and 597 ft-lb.
Try this link; sort of a cobbled together EPC:
And compare part numbers for different hp versions (like turbos, piston oil squirters, pistons themselves etc).
For 904s or whatever engine:
Don’t know why there’s 2 OM904LA choices.
I find this site useful even though I run true EPC on Microsoft Sync, EPC doesn’t run on iPhone and this 7zap thing does work on iPhone.
I always check on true EPC before actually ordering parts.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #3 ·
The 924 is hard to find for some reason here…
But I’ve found an Atego 1223 from 2001 I’m thinking about…
I know I wanted (and still do) a 904, but this one might be too cheap to let go.
Engine is OM906.910, so 170kW or 231hp, gearbox is the heavier G85-6 but the upside to that is that it is 0.73:1 i sixth gear.
Engine dimensions are almost identical to the OM352A, and I might be able to move it a bit backwards to make room for thw I/C
 
1 - 3 of 3 Posts
Top