606 Turbo vs 606 NA - PeachParts Mercedes-Benz Forum

RussG · #1 05-13-2013, 03:30 PM

Hello this is my first post and I guess you may think an odd question. I.E I want less not more!

I have a 463 series G Wagen with a 603 engine. I’m considering a 606 conversion but my priorities are simplicity over out right power. Despite what some may say even the factory 606 turbo G Wagens suffer from high under bonnet temperatures and I use my G Wagen for overland trips in to Africa.

I’ve driven a normally aspirated 606 engined G Wagen and it ticked all the boxes for me. Drove way better than my 603, and a relatively simple conversion.

So to get to my question.
Does the turbo 606 have the same compression ratio as the normally aspirated?

The reason I ask is that 606 turbo’s are very common and cheap in the UK as well as being newer than the available normally aspirated ones.

So the plan would be. Get a 606 turbo, ditch the turbo and replace the injection pump with my mechanical 603 pump.

Thoughts appreciated.

dieseldiehard · #2 05-14-2013, 12:03 AM

The NA 606.912 and the turbo versions 606.961, .962 and (from the G model).964 all appear to have the same 22.0:1 compression. Removing a turbo for simplicity is a reasonable approach but there are electronics in the overall systems that may present a problem, you would want to check out the wiring and modules and sensors involved, so a lack of boost isn't a feedback issue.

And in Africa I'm certain the Cat converter can be dispensed with!

Why wouldn't you keep the 606 Inj Pump? I can't tell what the results might be if you installed a 603 pump, I'd ask a Bosch service shop where they are familiar with the specs on the different IP's. That said, I have planned to install a 3.5 l IP on my 603 someday, actually need to call and see what all is involved with setting the fuel delivery for the 603 turbo.

I would suggest adding a puller fan to move air through the radiator if you are experiencing high temps.
A more expensive but effective solution would be to order a custom 3-pipe radiator (triple row of vertical pipes). I added one to an old 617 turbo and the car never overheats, even on the hottest day climbing a long, steep grade (ie. California's notorious Grapevine).
The radiator shop that made this for me (Sun Valley Radiators) no longer does custom work but there are places that would probably make one out of aluminum as for race cars, and in the process you will end up with an all-welded design with no rubber seals like the modern Behr design.
Don't be tempted in removing the thermostat, you need the coolant to reach something like 80C running temp.
DDH

KarTek · #3 05-14-2013, 06:28 AM

Just a couple thoughts:

Putting the 603 pump on the 606 and removing the turbo will essentially reduce the power level of the 606 to below the turbo 603 or about the same as the non-turbo 603. The 606 pump has 6mm elements where as the 603 has 5.5mm.

High under hood temps can be mitigated with exhaust wrap, high temp coatings, snail covers, etc...

So, to break it down:

OM603 NA ~ OM606 NA with 5.5mm pump.
OM603 Turbo ~ OM606 NA with 6mm pump. (Requires modified 603 pump)
OM606 Turbo will also require modified 603 pump in this application unless you can get a mechanical 6mm pump.

RussG · #4 05-14-2013, 01:05 PM

Thanks for the replies Gents.

The non turbo 606 has around 136bhp which is adequate for my needs. I’m going for simplicity of conversion and subsequent use. I would be concerned about the longevity of the 5 speed Getrag gearbox with the turbo as well.

Clearances are tight on a rhd G Wagen due to the proximity of the steering column and steering box. It can be done, plenty have.

I figured putting the 603 injection pump would be my way around the electronics. I’m not totally opposed to the electronically managed pump though.

I appreciate the 5.5mm vs. 6mm thoughts but figured that with some tweaking the 5.5mm elements would get me back to around the 136bhp.

Based on your replies it looks like it could be a feasible plan. Best bit being there are loads of turbo 606’s around from relatively young cars for around $500

jay_bob · #5 05-14-2013, 01:20 PM

The 606 turbo engine (as found on the 98-99 E300Ds) is drive by wire. It is not like the 603's EDS that just helps with idle management, the computer runs the whole show on the 606. The go pedal is a potentiometer that tells the computer how much speed the driver wants, and then the computer decides how much to pull the rack. It ties into the ASR/ABS/ESP/cruise control systems as well via CAN bus.

I don't know if the 606 DBW pump can be reworked to a mechanical pedal. If so that might be an option.

Jeremy5848 · #6 05-14-2013, 03:50 PM

How about using a 606 pump from a 1995 E300 (W124)? That is a completely mechanical pump (like the 603 pump) but without an ALDA since the 1995 E300's engine is not turbocharged. Such an engine would need no electronics at all because you can get along without EDS -- in those years/models all it did was to control smog and idle speed.

Jeremy

RussG · #7 05-14-2013, 04:13 PM

Quote:

Originally Posted by Jeremy5848

How about using a 606 pump from a 1995 E300 (W124)? That is a completely mechanical pump (like the 603 pump) but without an ALDA since the 1995 E300's engine is not turbocharged. Such an engine would need no electronics at all because you can get along without EDS -- in those years/models all it did was to control smog and idle speed.

Jeremy

Yes I like that idea.

Basically I can pick up a 606 turbo engine very easily and they were used up to 2001, so relatively young. Then either find a mechanical 606 pump off a W124 or if necessary use my 603 pump.
I appreciate I'll have to do something with the oil feed to the turbo but other than that it looks like they are the same engines.

Alastair · #8 05-14-2013, 04:45 PM

606 N/A Pump has 5.5 elements just like the 603 pump. Only the Turbo 606 has the 6mm elements.

--Turbo 606 pump is fully electronic --forget using that, you'll need EVERY electronic system from Donor vehicle including the dash, and gearbox etc. All comms by CAN-BUS--Anything missing/not happy and you'll not start or just go 'limp-home' modes! Thats electronic Crap for ya!

Stand-alone controllers I suppose are possible but I wouldn't trust one!

Be advisable to change the Nozzles in the 606 Turbo injectors to suit the 603 pump delivery rates--The originals in 606 turbo have narrower shanks and have a different delivery rate suited to the 6mm elements. Advise use DNOSD261 or DNOSD265 set to 125 bar. You'll need to take the injectors to a specialist to do this, and explain exactly what you want and why--Or they will just replace with the original DNOSD315 nozzles. The shims will need to be replaced to set the pressures down to 125 from the original 155 used with the '315 and as the shims are a smaller size series than the usual KCA series injectors in 603, only a few specialists have them.

--I did a set for a friend, and had to grind down KCA size to fit the 606 injectors Right PITA!...

Why bother searching out one of those n/a 606 pumps? Stick to the Mechanical 603 pump, shove that in, and adjust the max fuel settings IF NEEDED.--Not hard, Check out the how-to on STD.

The std. setting in 603 pump will probably lead to a somewhat higher power than in the original n/a 603--provided the injectors are done as above--due to the general greater breathing and improved combustion-chamber layout of the 606 engine.

Go for it, Should be a nice job and a good improvement.

jay_bob · #9 05-14-2013, 07:23 PM

Quote:

Originally Posted by Alastair

--Turbo 606 pump is fully electronic --forget using that, you'll need EVERY electronic system from Donor vehicle including the dash, and gearbox etc. All comms by CAN-BUS--Anything missing/not happy and you'll not start or just go 'limp-home' modes! Thats electronic Crap for ya!

I forgot, it's not just the engine, it's the transmission as well on that CAN bus. No chance at all transplanting that engine to anything older, unless you happen to be a development engineer at MB and have access to the source code for the various control modules.

Alastair · #10 05-14-2013, 07:45 PM

Quote:

Originally Posted by jay_bob

. No chance at all transplanting that engine to anything older, unless you happen to be a development engineer at MB and have access to the source code for the various control modules.

Err--Not so!

Just Dump The Pump!--Thats the Main stumbling-block

Fit a Mechanical I.P. from a 603--Turbo or N/A depending on your needs--fits right in, do the basic mods to injectors and away to go--No electronics to worry about anymore if you run the turbo motor as N/A with N/A exhaust-manifold...

For the Turbo--You will need to change that as the wastegate is vac operated on 606 and controlled electronically, but that shouldn't be much of a prob to find a suitable replacement (and better) turbo!
--Only real issue--IF you want to make more than say--250 BHP from 0M.606 Turbo motor--The stock turbo exhaust-manifold is utter CRAP--looks and flows like a nobly turd.....

The Finns however make some beautiful manifolds for this engine suitable for a variety of turbos--even huge Holsets...

I have a Turbo 606 that (one fine day) I'll fit to one of my W123 Wagons....

KarTek · #11 05-14-2013, 08:37 PM

One other thing to note about the 606 is that it depends heavily on the elegantly designed, active tuned intake manifold to generate some of it's HP.

RussG · #12 05-18-2013, 04:27 AM

Gents,
Thanks so much for the replies. This was just the sort of technical information that I needed.

Of course I may well be able to pick up a W210 with the normally aspirated 606 in it, I don’t really want to cannibalise a W124 though. It’s just that MB only imported the NA 606 in the W210 for maybe 2 years so my choices will be limited. Going for the turbo opens up lots more options, there are loads of dying W210’s around which still have great engines in them.

I really think this will be the ideal engine in my G Wagen. Better day to day drivability on my local highways, improved refinement, better economy but with long term durability and simplicity. Who knows why MB never used these at the factory.

Yes I appreciate the comment re. the intake manifold, it's a tight fit in the G Wagen engine bay.

It’ll probably be Autumn when I carry out the swap, I’ll let you know how I get on.

cantankerousoldyankee · #13 12-07-2014, 09:48 AM

This is old, but for posterity's sake, I should point out that the issue of the variable length manifold in the NA, which give it it's gas saving and high revving powers, has been overlooked in this thread. They are vacuum operated, but electronically controlled. What the impact on performance would be if disabled is yet to be discussed anywhere I've looked on the internet.I'm doing to be trying it myself soon on a 95.

sixto · #14 12-07-2014, 05:01 PM

I'm scratching my head over this one. If simplicity is fundamental, why would you set out into the bush with an intake manifold hiding all the bits you want to be able to get to quickly? I wouldn't call a turbo more complicated than the variable geometry intake manifold of a NA 606, and I read of more problems with NA 606 intake manifold actuators than turbos. Finally, what kills a transmission is your footwork, not a turbo. A 606 turbo with a 603 IP upgraded by Myna or someone competent to 6mm elements seems like the fully mechanical way to go.

Sixto
MB-less

RussG · #15 04-14-2015, 06:37 AM

Hello Gents,
I thought I would give you an update on my project. It's not quite complete yet but it is up and running.

I found a 606n.a. which is running really well, I've put a couple of utube links below. It was a reasonably easy swap. Sump swapped for the G Wagen one plus oil pump, oil filter housing so that I could use the separate G Wagen oil cooler, torque converter swapped for the 603 fly wheel and clutch and that's about it.
I did try to keep the resonance flaps but in the end disabled them. Plus I ditched all the emission control stuff and the multiple superfluous vacuum pipes etc.
Compared to the very tired 603 it's a revelation, I'm really really pleased. Still some final tweaking to do such as figuring out a mb air intake / filter arrangement and I'm planning on tweaking the IP to get a little more power.
https://m.youtube.com/?#/watch?v=F9gP9xK98HE

https://m.youtube.com/?#/watch?v=x_U4KSrKcwU