Idle question - conversion of W124 to turbocharged OM606 auto

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Charles Morgan

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Mercedes 250CE W114, Alfa Romeo GT Coupe 3.2 V6
Thinking (merely a gleam at present) about a turbocharged OM606 into a W124 estate. Much as I love the 300 multivalve non-turbo W124, I find it needs more torque, a five speed auto and a less frenetic rear diff ratio to make it a really relaxing car.

First option - fit turbo in the manner of the hooligans elsewhere. Is there a 5 speed auto that can handle the torque and run without an engine ECU requirement?

Second, transplant W210 OM606 turbocharged engine and auto etc (there's plenty of em!).

Ease of conversion rather important.

Thoughts welcome.
 
Other than the manual injection pump swap... if you do a YouTube search for Olefejer's channel he has a stand alone controller for the 722.6 box on a 606. Complete with paddle shift.
 
I'm entertained by him hooning around in a W140. That would be different.

Mechanical injection pump, large turbo, boost control and 722.6 box with controller. Should be fun to do.
 
If you do go for the large turbo hooligan option, you wont be as concerned about having the 5 speed auto. These engines make so much torque you can cruise around in a high gear all day, the 4 speed fitted with a first gear start modification is just as good.

To give you an idea I only need to use 2nd, 4th, and 6th for normal day to day driving. The others normally just aren't needed.
 
With the issues of ECU's, exhaust clearance and manifolds etc, I'm surprised more people don't supercharge the 606 multivalve !!
 
If you do go for the large turbo hooligan option, you wont be as concerned about having the 5 speed auto. These engines make so much torque you can cruise around in a high gear all day, the 4 speed fitted with a first gear start modification is just as good.

To give you an idea I only need to use 2nd, 4th, and 6th for normal day to day driving. The others normally just aren't needed.

Would the existing 4 speed auto in a multivalve be strong enough? I know Nick Froome was sceptical when asked when Druk was planning his 107 conversion.
 
With the issues of ECU's, exhaust clearance and manifolds etc, I'm surprised more people don't supercharge the 606 multivalve !!

They do, but quite often have it feeding the turbo.;)

In all honesty there was never an issue with manifolds and exhaust clearance (Druk's sl being the exception), it's just autobox'es that need some thought.
 
Would the existing 4 speed auto in a multivalve be strong enough? I know Nick Froome was sceptical when asked when Druk was planning his 107 conversion.

It should handle the 180hp the standard 606 turbo put's out, if you want big power then it will need to be upgraded. Unless your going to floor it everywhere I think will cope just fine.

I'd almost do that myself with a cheap e300 just for a laugh, wind up the power till the gearbox gives up!
 
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I'm entertained by him hooning around in a W140. That would be different.

Mechanical injection pump, large turbo, boost control and 722.6 box with controller. Should be fun to do.

You sure it's a 140 Charles? I think it's a 129 he has it in. I've had conversations with him re his controller and if it wasn't for tunnel clearance issues I would have one in the 107. It's a clever toy because he also has boost control which by far betters (or simplifies) the Merc vacuum set-up.





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Simon - I think Nick's point, as much as anything, is the boxes aren't ageing well, numerous flaring ones. If I'm going to the trouble of fitting a turbo, I want oodles of torque and a box that will eat it for breakfast for many years to come.
 
Find a good 4sp box (or have one rebuilt) and I can recommend an ATF that will see the box last forever.
 
Rendered Dodo fat?
 
They do, but quite often have it feeding the turbo.;)

In all honesty there was never an issue with manifolds and exhaust clearance (Druk's sl being the exception), it's just autobox'es that need some thought.

I don't know Druk's car to be honest but I know a Polish lad who has supercharged a 606 and by messing about with pulley sizes etc has come up with a very useable engine. I believe the box he used came from a late 210 320 CDi with modified electronics.
 
Something about that place would make any mythical or real creature sob.
 
Simon - I think Nick's point, as much as anything, is the boxes aren't ageing well, numerous flaring ones. If I'm going to the trouble of fitting a turbo, I want oodles of torque and a box that will eat it for breakfast for many years to come.

I suppose it come's down to what you decide to do engine wise, there's a couple of ways you could go about this swap.

1. Fit the turbo 606 with the old 4 speed auto and mechanical pump, should give you the 180hp and 250ftlb the w210 has.

2. Fit everything from the w210 donor car including the 5 speed box, ecu's ect. Basically a w210 in a w124 shell.

3. Fit the 606 turbo engine, but control it with the ecu and loom from a w202 c250td.

4. Build a 500hp turbodiesel, control the 5 speed with the aftermarket controller, or fit v12 internals in the 4 speed.
 
Ideally I'd like something with a bit more poke than a 210 (or indeed 250lbft). Not really that keen on 500bhp.

Given how many 210 300tds are on the way out at present, it would seem to be a good place to start though.

Option 3 intrigues me.
 
Ideally I'd like something with a bit more poke than a 210 (or indeed 250lbft). Not really that keen on 500bhp.

Given how many 210 300tds are on the way out at present, it would seem to be a good place to start though.

Option 3 intrigues me.


The thing is, to get a worthwhile output from the 606 you'll need to go with a mechanical pump and different turbo. But you'll spend roughly the same amount of money to get the 606 to produce 300hp, as you will to get 500hp out of it.

Option 3 just means you can run the om606 on it's original fuel pump, without the ecu needing to talk to the gearbox. Quite useful for running a standard 606 turbo engine in a w124.

I know this thread is about the om606, but would the 270cdi engine not be better suited to what your thinking of doing?
 
The problem with the 722.435 in the W124 is that it's controlled by a Heath Robinson system of vacuum pipes, restrictor valves & etc. It works brilliantly a lot of the time but cars tend to develop flaring which wears out the clutches. A higher-torque engine is likely to make that process faster

Taking an engine & box out of an early W210 E300 turbo diesel might be the simplest way if it can exist as a standalone setup without all the electronics from the W210. My knowledge of W210s is scant and I don't know if they all had EIS key systems & all that malarkey

A Sprinter engine might also be an option but I assume the gearbox is unusable as the vans are (mainly) FWD

Once you get up to a 270 or 320 Cdi engine I imagine you have ECUs out the wazoo

The E300 Diesel lacks torque and a higher top gear. A simultaneous solution to both those problems would be ideal

Nick Froome
 
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The thing is, to get a worthwhile output from the 606 you'll need to go with a mechanical pump and different turbo. But you'll spend roughly the same amount of money to get the 606 to produce 300hp, as you will to get 500hp out of it.

Option 3 just means you can run the om606 on it's original fuel pump, without the ecu needing to talk to the gearbox. Quite useful for running a standard 606 turbo engine in a w124.

I know this thread is about the om606, but would the 270cdi engine not be better suited to what your thinking of doing?

The question of money is a separate issue, but something producing 500bhp is far less desirable to me than something producing 300. That capability may still be there, but working at a lesser state of tune/boost is fine.

Noted on gearbox, but as Nick says above, gearbox will not likely be the original 4 speed.

A 270 engine has no appeal. The straight six indirect injection 606 is the only reason I'd do this.
 

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