W126 short body OM606 - Printable Version

W126 short body OM606 - Printable Version

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W126 short body OM606 - WSchotty - 06-25-2018

Hello diesel fans.

I have been browsing this forum for quite some time and figure it is time to give back with some information about my latest Mercedes project.

Here I will document the build of a replacement for my current daily driver, a 1983 W126 with om617. That car's chassis has in the neighborhood of 700k miles and has seen abuse no other car could handle. I initially started refreshing that body but have continued to find more and more damage that isn't worth the time to restore, so decided to find a good example generation II short body. I'll make another thread someday about the build I did in 2005 on the '83, but for now I'll focus on the new car. I found a 1991 350SD which had a blown engine and excellent interior with minor paintwork needs, then drove 2600 miles to pick it up.

The car will have the following specs:
7.5mm Dieselmeken pump
BW S200 from the DPUK guys
722.6 from S55
2.46 LSD

Here it is after loading with come-along in Portland, ready for the journey back. Towing Jeep has a om642/722.6 and rear airbags so was not a problem capacity wise:

[Image: 20180206090705.jpg]

However, along the way the trailer blew two tires at different times in the trip:

[Image: 20180208110421.jpg]

Then I get close to home and run through the carwash to get all of the magnesium chloride off, very excited to get home:

[Image: 20180208155828.jpg]

Shortly after leaving the carwash I look in my rear view and see a shower of sparks and smoke once again...
[Image: 20180208173727.jpg]

This time it had to get a flatbed ride on a medium truck the rest of the way home, rental trailer rusted out leaf spring shackles couldn't take any more. Car was right at the rated weight of that trailer.

Here it is with the '83:

[Image: DSC03956.jpg]

Here is the unmolested interior, best w126 I have seen in awhile:
[Image: 20180520144911.jpg]

I started stripping down the old car, here are photos of the original configuration of the IP in case anybody ever needs to see that:
[Image: 20180211151331.jpg]

And the stripped om603 with it's replacement:
[Image: 20180312181227.jpg]

I sent the mechanical pump off to Dieselmeken for 7.5mm rebuild:
[Image: 20180220115554.jpg]

The OM603 suffered failure from the oil pan baffle washers being ingested by the oil pump.

Here you can see the impacts on the oil pump gears and washer:
[Image: DSC03959.jpg]

This sheared the oil pump sprocket bolt in half, and blew out the front of the timing cover:
[Image: 20180213081958.jpg]

The previous owner said they shut it down immediately, but not soon enough:
[Image: 20180508092400.jpg]

Damage was worst from front to rear of the crank. Pistons were trashed, no reason to try and save this engine.
[Image: 20180507202054.jpg]

I have been collecting parts from the junkyard for the W126 build for the last 15 years or so, and had originally selected a 2002 S500 transmission since the output flange is the same dimension as the one on the 350SD driveshaft.

I have piles of W126 crap that needs to be sorted one of these years:
[Image: 20170808124149.jpg]

About the time I got the S500 and 722.3 transmissions out of storage I happened across a 2002 S55 in the pull it yourself yard:
[Image: 20180311140859.jpg]

I grabbed the transmission and a few other goodies, including the S320 alternator and transmission cooler lines from the W140 in the picture:
[Image: 20180311172050.jpg]

I'll find out in the near future how that AMG muffler flows with the OM606.

I think the OM606 may have come from a flood car, I picked it up in Houston after the hurricane for very cheap. The only problem I found was heavy corrosion in the injector wells.

I cut a tarp and sandblasted the wells in a similar fashion to intake valve cleaning on the BMW diesels:
[Image: 20180429163733.jpg]

The lines kept the media out of the injectors.

Once the corrosion was removed, I pulled the injectors and sent them out for rebuild with 150 bar pop pressure. This left cleaning the carbon out of the glow plug and injector holes:
[Image: 20180501113823.jpg]

Scotch pad on a shaft:
[Image: 20180501142914.jpg]

I ground down some drill bits to use to clean out the injector holes (by hand), they worked perfectly in place of a reamer.
[Image: 20180501111326.jpg]

I tapped out the water pump housing for the bypass hose:
[Image: 20180415131709.jpg]

There was some additional drilling and tapping needed for the older style RPM sensor. This is a 18mm drill hole size for the sensor, and I used m6x1 for the attaching screw:
[Image: 20180517111057.jpg]

More to come soon...

RE: W126 short body OM606 - WSchotty - 06-25-2018

Sorry about some of these images, the hosting site I used has some autorotation that can't be changed apparently.

The oil filter housing from the om603 has some clearance issues:

[Image: 20180325141955.jpg]

This was alleviated by removing material from the intake tube and housing with a belt sander:
[Image: 20180325144752.jpg]

Now the oil cap can be removed without pulling the intake! Will have to see if I went too thin on the lid though.

A little support is needed to be welded to the OM606 cooling tube to make it work with this housing:
[Image: 20180506204550.jpg]

Injection pump timed, installed along with a new metal impeller water pump:
[Image: 20180506113619.jpg]

Here you can see how far 8 was from the original setting ~14 in the viewing hole:
[Image: 20180506113542.jpg]

The thermostat housings are different, and to use the original hoses I had to use the original smaller om603 one:
[Image: 20180424160903.jpg]

I wanted to retain the original Nippon AC pump from the 350SD. I left it charged and hanging in the engine bay. The base plates for the alternator and AC pump have slight differences between engines:
[Image: 20180508195457.jpg]

Note how one of the alternator plates has clearance on the back for the crank pulley on the OM606. The OM603 version would need slight modification.
[Image: 20180429110144.jpg]

6031550735 right, 6031550435 middle, 6052140239 left . The compressor mounting holes between the E300 and 350SD have different dimensions .
[Image: 20180429110113.jpg]

Here you can see the different nose length on the 2002 S500 V8 alternator vs the late 90s W140 S320 I6 alternator, I6 on the left:
[Image: 20180311172105.jpg]

The S55 transmission took a beating in its accident, but damage appears to be limited to the pan:
[Image: 20180311184846.jpg]

With the E320 bellhousing and new intermediate plate (seal) and better pan installed:
[Image: 20180507175946.jpg]

The output flange on the AMG transmission is 4 finger, while the 2002 V8 version has an exact match 3 finger dimension to the 91 350SD driveshaft.

Here we have some side-by sides of various transmissions:
90s E320 I6 next to original from 350SD and S500:
[Image: 20180213103600.jpg]

300SD -> 350SD -> E320
[Image: 20180311172146.jpg]

300SD ->350SD -> E320 -> S500 -> S55
[Image: 20180311172050.jpg]

For now I just used the torque converter from the E320, hopefully it isn't fried. The S55 had very low miles, pink fluid.
Here are S55 AMG left and S500 flanges:
[Image: 20180514120825.jpg]

The S500 flange is not the same as the E320, this one is much smaller than the 350SD and S500.

Here are the turbos I had out of storage next to each other:
E300 left, 350SD right
[Image: 20180508103713.jpg]

E300 top, S200 bottom
[Image: 20180508103729.jpg]

The pile in the garage is getting excessive:
[Image: 20180319164359.jpg]

Time to pull the body in:
[Image: 20180306123044.jpg]

And now we find out how far off everything is:
[Image: 20180517173319.jpg]

To my amazement, everything lined up like it was designed for this combination.

[Image: 20180517180237.jpg]

Will have to reroute the heater core lines a bit:
[Image: 20180517195433.jpg]

Perfect, that is the 99 E300 pan in the W126
[Image: 20180528173418.jpg]

The DPUK adapter
[Image: 20180612152303.jpg]

Cleaned out the original oil cooler
[Image: 20180528173444.jpg]

And the biggest question of the day, the driveshaft. It fits perfectly with the original flex discs.
Now if these start to fail to frequently, the S500 has much thicker discs that can be used but will require a couple CM removed from the overall shaft length. Time will tell...
[Image: 20180528173343.jpg]

I got lucky and found a 125k mile LSD from a 560SEL at the pull it yourself yard:
[Image: 20180520131814.jpg]

And now there is a company making full aluminum replacement radiators for the gen II W126 diesels:
[Image: 20180403152504.jpg]

The belt is not the same size due to the different accessories. I used a 2153 mm belt for now as it was the closest fit, but a few mm shorter may be needed. The main vacuum tube bolted directly up to the vacuum pump like it was original.

Thats as far as I am now, I still have to do the following:
Build 3" exhaust
Mock up intercooler size and order
Wire everything and install shifter - will be using the Ole controller for the transmission
Extend heater core hoses to their new homes
Build transmission cross member for the 722.6 mount
Boost hoses, gauge, and EGT gauge
Fuel system - I pulled the pumps from the 560SEL and am going to try to use one of them with a external adjustable regulator in the stock gasser location. If that doesn't do a 044.

Right now I am saving up for a new welder as the china welder I have gave up the ghost on the oil filter housing coolant tube. I'll update the thread when I make some more progress...

RE: W126 short body OM606 - Sotvisp - 06-26-2018

Fantastic post good work !!

RE: W126 short body OM606 - awsrock - 06-27-2018

Heck yeah, blazing speed progress! I have a mild 300SDL with a 603 and am planning on one day putting a 606 in there, so this thread will prove most helpful.

I also have a 722.6 sitting in the garage waiting for me to have some time to put it in. Good to know the stock flex disc works perfectly.
Do you have any concerns about the low 2.46 LSD? With the overdive, your rpms are going to be super low. I got the "small" 722.6 hoping the smaller first and second gear would help with off line performance. Will be interested to see how it works for you, if I need to upgrade to a bigger rear axle I may look for a ....350SDL model? Perhaps we will need to talk about that if you don't need your old one.

Pretty much nobody mods these 126s but that front bumper is gold for putting in an intercooler. Right now I have a 27x9 stuffed in there with no problem. I just had to grind off maybe half an inch of the plastic on the inside. I could probably get up to a 27x12 without it sticking out from the top or bottom too much. Consider boring out the two holes in the engine bay that have a rubber part in them, they are good routes for IC piping.

RE: W126 short body OM606 - WSchotty - 06-28-2018

Thank you Sotvisp.

awsrock,

Glad to hear there is somebody else out there building W126s.

I'm interested to see how the 2.47 runs with the OD transmission. The extra power with that diff will probably be fine, I'm not drag racing this one. I've had a 380SE 2.47 in the om617 83 W126 since around 2002 and it is a whole different car. Given that the car usually started in second and was essentially a 3 speed most of the time the 2.47 made it a excellent highway cruiser, and the shift points make the approximate speed ranges 1st ~20mph | 2nd~ 40mph | 3rd~60mph | 4th~have hit 120+. This actually improved the mountain driving too, most of this car's life has been DD at 5000-9600ft above sea level running mountain roads, it really doesn't do too bad for a 100hp car.

The 350SD 2.82 diff is the same case size as the 2.47, so I will probably keep that if the gearing is wrong for that 722.6. I also have a 2.88 small case diff from a 87SDL in case I need to go even higher, but will lose LSD in that case. I am kicking myself for letting a 350SD diff and driveshaft slip through the junkyard a couple years ago, I never anticipated actually owning one of these. They use a 3 piece driveshaft rather than the 2 piece. I have an extra SDL 2 piece if you need one of those.

The intercooler does have plenty of room, I am probably going to go with 28x12x3 or 3.5. What width did you use? I also found one that flows 7 or 800 cfm that will fit completely in the lower part of the bumper, but I'd rather have excess capacity due to the long uphill pulls this engine will see. I need to make a cardboard version for test fit before I order.

Here are W126 ratios in case anybody wants them:
w126
1st Generation w126
Years,Model, Engine, Differential Ratio, Differential Case Size
1981-1984, 300 SD, OM617.951 3.0L I5, 3.07,
1985, 300 SD, OM617.951 3.0L I5, 2.88, 1.1 Liter (California from 10.1984 in California: 2.88, 1.1 Lite
1984-1985, 380 SE+SEL, M116.963 3.8L V8, 3.27, from 1981-10, 2.47, 1.3 Liter
1982-1983, 380 SEC, M116.963 3.8L V8, 2.47, 1.3 Liter
1984-1985, 500 SE+SEL, M117.963 5.0L V8, 2.82, from 1981-10, 2.24, 1.3 Liter
1984-1985, 500 SEC, M117.963 5.0L V8, 2.24/2.24 LSD (2.47?) 1.3 Liter
2nd Generation w126
Years, Model, Engine, Differential Ratio, Differential Case Size
1989-1991, 300 SE, M103.981 3.0L I6, 3.46 1 Liter
1988-1991, 300 SEL, M103.981 3.0L I6, 3.46, 1 Liter
1986-1987, 300 SDL, OM603.961 3.0L I6, 2.88, 1.1 Liter
1991, 350 SD, OM603.97 3.5L I6, 2.82, 1.3 Liter
1990-1991, 350 SDL, OM603.97 3.5L I6, 2.82, 1.3 Liter
1986-1991, 420 SEL, M116.965 4.2L V8, 2.47, 1.3 Liter
1986-1991, 560 SEL, M117.968 5.6L V8, 2.47 ASR/2.47, 1.3 Liter
1986-1991, 560 SEC, M117.968 5.6L V8, 2.47 ASR/2.47 LSD/2.47, 1.3 Liter

RE: W126 short body OM606 - awsrock - 06-30-2018

Interesting to hear how the 2.46 did in the 617. For a while I was torn between the 722.6 and just swapping out for a different axle. Ultimately I chose the 722.6 because of all the unknowns about how much the .3 can handle. They make a clutch upgrade for the .3 but it's like $700 so kind of moot once you factor in a .6
Mine is fine right now with 240 ish hp, but ultimately I am planning on 300-330 once I get another new pump.

I want to say my IC is 3" thick. The outlets are 2.5" so it is possible that it is only 2.5" thick but I doubt it. Here is how it looks in there now. If you exclude the mounting posts on top there, there is probably another inch and a half to two inches before the top of the bumper. It is sitting on the bottom of the bumper. So even if you cut out a portion of the bottom to have it hang out a 12" tall IC should fit with little effort. It gets a little cramped if you go wider than 27" due to the curvature of the bumper but you can probably grind out more of the inside.

RE: W126 short body OM606 - WSchotty - 05-12-2019

Finally had some time for work on this one, made the exhaust and started mounting up the intercooler.

What the downpipe ended up looking like, decided to dump the wastegate into the main exhaust:

[Image: 20190327123851.jpg]

Flex fitting for after transmission mount, hopefully will reduce stress on the turbo:
[Image: 20190327143903.jpg]

Installed:
[Image: 20190327150155.jpg]

Added a couple bolts for adjustment on the w220 mount:

[Image: 20190327155720.jpg]

Here you can see the temporary transmission mounting, a W220 pate grafted onto a W126 pate with some support metal welded on. Someday I'll make a nicer version, but this will work for now.
[Image: 20190510181551.jpg]

I built the exhaust in three pieces with band clamps for ease of driveshaft service and rear differential/cv swap.

Don't mind the booger welds, here you can see I had a few too many and forgot to turn on the gas. Amazingly, the pipe still holds gas, not pretty though.

[Image: 20190510160006.jpg]

I used all the stock mounting points I could. I may still add a lateral brace between the old kidney bean muffler mounts once I get done under the driveshaft plates and finalize everything as there is too much side to side movement for my comfort.

[Image: 20190510181538.jpg]

Patchwork of W123 mounts grafted onto a couple pieces of metal:

[Image: 20190510155953.jpg]

Still not sure how well this W220 AMG muffler will do, hopefully will get to find out soon enough. I put one of the resonators from that car on my om642 and it seems to flow just fine, this one I'll add a resonator if it is too loud but want to try without first.

Tip alignment (she tells me this is important)

[Image: 20190511154036.jpg]

Went for the biggest intercooler I could possibly cram under the bumper:

[Image: 20190511133846.jpg]

It will work, but is going to have some mild modifications:
[Image: 20190511142812.jpg]

The front pull is in the way:

[Image: 20190511142839.jpg]

I made some cheater plates to hold the bumper out a little more. Off of these I'll build the mounts for the IC so modification of the body is minimal.

[Image: 20190511152817.jpg]

I want to keep the bumper as stock looking as possible, worst case I can take off this lower support bar and redesign the front lower radiator support, but really trying to make it work without that first:

[Image: 20190511142849.jpg]

Have a couple mm around the sides and bottom, that is the lower lip of the bumper and bottom of the IC:

[Image: 20190511142857.jpg]

Will keep updates coming, hopefully more frequently than yearly...

RE: W126 short body OM606 - Tobulus - 05-13-2019

Very nice!

RE: W126 short body OM606 - WSchotty - 07-17-2019

Had a few more hours to put into this one, got the intercooler plumbed up and mounted, and started on the fuel system.

[Image: 20190608121313.jpg]

Core size is 10.5" (26.67cm)x 22" (55.88cm) x 3.5" (8.89cm) with overall length of 32" (81.28cm)

Made the mounts such that the whole assembly comes with the bumper mounts.

I did have to trim back the lower radiator support a little:

[Image: 20190608125352.jpg]

Reinforced with thicker steel and flat supports:
[Image: 20190608132553.jpg]

A little clearance in case the bumper gets lightly tapped:

[Image: 20190608132821.jpg]

Picture of the mounting brackets:

[Image: 20190612102857.jpg]

The new front pull:

[Image: 20190612104359.jpg]

Had to make a stainless hard tube to get around the om603 oil lines and squeeze down by the AC pump:

[Image: 20190705145623.jpg]

Some IC tubes:

[Image: 20190717090628.jpg]

Even put the splash shield back on to keep water off the alternator:
[Image: 20190717101802.jpg]

Oil cooler splash shield:
[Image: 20190717101819.jpg]

And the fuel pumps. Going to try and use one of the w126 gas pumps with an aftermarket regulator to hold the 1.5 bar:

[Image: 20190717185742.jpg]

Next just need to plumb the fuel lines and see if the pumps can handle the more viscous diesel fuel...

RE: W126 short body OM606 - WSchotty - 11-06-2019

Some more progress, the fuel system turned into a larger project than expected as the tank was full of sludge:

[Image: 20190910093750.jpg]

I decided to use the fuel tank from the other car, which means it is time to decommission the 83.

[Image: 20190910093604.jpg]

While I had the tank and differential out I had to patch up some surface rust spots:
[Image: 20190807125432.jpg]

The "audio card" from the 83, something similar may find its way onto the 91 but the music of the engine should be enough for the next year or two:
[Image: 20190912100125.jpg]

I ended up using a gas fuel strainer and intake line for the larger size, the only disadvantage to this is the strainer screen size on the gas is much finer than the diesel. This could cause no flow if the fuel gels and might clog up like a prefilter. If this becomes a problem I'll have to swap the screens between the two.

The small nipple on this elbow was filled with solder:
[Image: 20190912132757.jpg]

I made a little bracket for the firewall and mounted the regulator in the engine bay:

[Image: 20190724110217.jpg]

The single stock gas pump is plumbed through the mechanical pump, but will hold 25psi on it's own:
[Image: 20190725135303.jpg]

Once the fuel system was up and running, setup the transmission wiring and shifter:

[Image: 20190918121623.jpg]

Used a rod from a w220 or w140, it was just a little long and needed trimmed down and threaded:

[Image: 20190918195625.jpg]

The bolts didn't line up, and had to use a washer to hold one of the four in. It would be better to cut out the area and weld in a new plate but this will be fine for now.

[Image: 20190919095215.jpg]

Once I buttoned up the rear end, finalized the exhaust and added that lateral support I was talking about earlier:

[Image: 20190925145624.jpg]

Time to move up front, there was some more rust damage under the battery tray. I swapped out the sway bar mounts and sandblasted it out. The tray I had already redone in the 83, so swapped over the good parts:

[Image: 20191010115720.jpg]

You'll notice coolant lines into the washer tank, that is for heating of the fluid and battery. This is a shot inside, there is a thermostat on the end that controls flow:

[Image: 20191010115757.jpg]

For the heater core lines, the exhaust side of the engine I used a line from a 81-85 SD slightly modified, painted is the modified vs the old one from the 83:

[Image: 20191008123847.jpg]

This now runs on top of the spring perch:

[Image: 20191010121315.jpg]

I also made a steel mount to hold up the intake tube and filter.

Here you can see the short extension around the 603 oil cooler:

[Image: 20191010155742.jpg]

Found this perfect little elbow on a X5 CCV system:

[Image: 20191010170123.jpg]

Getting closer, just need to finish the throttle cable assembly, wire it all, and fill with juices.

[Image: 20191010170445.jpg]

RE: W126 short body OM606 - WSchotty - 11-07-2019

Here was today's progress, all fabrication is complete, now just wiring and fluids to go.

Throttle cable comes around from the front and in between the firewalls:

[Image: 20191107100124.jpg]

Then pokes out here:

[Image: 20191107090643.jpg]

Here you can see this adjustable cam lever I made from a piece of a Nissan that rides on the bearing:
[Image: 20191107090655.jpg]

Then the cable support made of steel:

[Image: 20191107090806.jpg]

Finished design, just needs the return spring on the pump and final adjustment:

[Image: 20191107100103.jpg]

This isn't the most elegant solution, but will work for now. I wish I could have used the rods and kept cruise control, maybe someday in the future.

And finally, the last weld on the car for awhile (hopefully). Installed the EGT sensor from the 83:

[Image: 20191107112123.jpg]

RE: W126 short body OM606 - WSchotty - 01-04-2020

Well, made a little more progress, nearly time for the first start now.

Moved the parts car out of the way:

[Image: 20191231134429.jpg]

Ready for a day of fun:

[Image: 20191231140020.jpg]

Here is the wire layout for the Ole controller plug that has TPS, boost, and another connector on it:

[Image: 20200101135307.jpg]

And if you need to take the connector apart, the Molex tool needed happens to be the same size as a regular computer power supply:

[Image: 20200101141325.jpg]

I took the connector off so I could thread the wires in the cabin through the fusebox, the stock holes are very small.

Some leftover harnesses after making custom glowplug hybrid 606/603 harness:
[Image: 20200101141259.jpg]

I kept all of the EDS system intact, so the comparison between AC pump and main RPM will still kill AC if belt is slipping. Flooring the car will not disengage the compressor now, that feature was eliminated. The om606 head only had spots for two coolant sensors, I kept the gauge sensor and glowplug sensor, but not the EDS sensor. For EDS cooling sensor I used a 243 ohm resistor so it thinks it is at operating temperature all the time.

Soldering in a extension on the old EDS cooling system wire:

[Image: 20200102084930.jpg]

The original hood pad keeps shedding on me, so ripped that out:

[Image: 20200102135833.jpg]

Some day in the future I will swap the steel hood and trunk for aluminum versions before paint, so just going to leave the pad off for now.

And finally finished up the engine portion:

[Image: 20200102195817.jpg]

Put a grille back on, the first time the hood was closed in a year or two:

[Image: 20200102142744.jpg]

That gap for the intercooler isn't too terrible. I might still have to chop out the top plastic of the bumper if it still gets too hot, but the idea was to keep it stockish looking. I have a curved light bar I might put across that dip in front of the grill to help cover up the gap and conceal the top of the intercooler.

All that is left now is to pull 4 more circuits in the cabin, install cameras, finish up interior wiring, finish interior trim, and final fluid level checks/fuel pressure settings, maybe this thing will run this year!

RE: W126 short body OM606 - turbojeep - 01-08-2020

Progress is coming right along. Looks like you're getting very close. Curious as to how you're doing to work that light bar

RE: W126 short body OM606 - WSchotty - 01-08-2020

(01-08-2020, 07:48 AM)turbojeep Progress is coming right along. Looks like you're getting very close. Curious as to how you're doing to work that light bar

Will have to see, I put one on the Jeep but it has a nice slot that fit pretty good, I live pretty far out so it is nice to be able to make the trees glow. Once I get it shined up and look at it a bit will think of some ideas, where it could fit. The only thing I don't like about them is it whistles like a Stuka siren above 80mph, brings too much attention.

[Image: jep.jpg]

I did get her going today, some more trim work to go and found that I used the wrong vacuum pump gasket.

There was prewiring for a CB, even the color scheme matched the original gasser fuel wiring:

[Image: trunkwire.jpg]

The OFGear controller fit nicely in the passenger computer cover:

[Image: OLECONTROL.jpg]

Put in 2 stage boost controller so can run low most of the time and flip a switch when extra is needed:

[Image: boostcontrol.jpg]

Finally replaced the AC drain hoses:

[Image: drice.jpg]

When I ran it, some oil was dripping down the front near the crank. At first I thought I screwed up the front main seal, but luckily I just used the wrong gasket on the vacuum pump:

[Image: drips.jpg]

My EDS plan isn't working out, I'll post a video soon of the first start, it was loping around so I'll have to nix that idea rather than try to work around all the missing EGR/intake sensors. I think the AC still will work with the original system, but the boost of RPM when compressor engaged will have to go. Once I get the new gasket in I'll try running it without the EDS hooked up.

RE: W126 short body OM606 - WSchotty - 01-08-2020

Video of first starting:

RE: W126 short body OM606 - turbojeep - 01-11-2020

[quote pid='90074' dateline='1578524289']

Will have to see, I put one on the Jeep but it has a nice slot that fit pretty good, I live pretty far out so it is nice to be able to make the trees glow. Once I get it shined up and look at it a bit will think of some ideas, where it could fit. The only thing I don't like about them is it whistles like a Stuka siren above 80mph, brings too much attention.

[/quote]

I hear you on being able to see where you're going. On the W124 wagon we used to have, I had some 7" high/low beam lights hung off the front bumper. In the end I had to get a bracket that was attached near the license plate goes, due to the way the grill swings outward when the hood is opened.

Congrats on the first start! It's a good feeling when it finally catches after the initial cranking.

RE: W126 short body OM606 - WSchotty - 01-19-2020

A small update this week. I replaced the vacuum pump seal with the correct one (A 604 238 00 80) to stop the oil leak, but found that there had been a new diesel leak from the fuel pump. I tried 3 different gas pumps, but they all eventually started leaking in the same place, from the crimp side of the body:

[Image: 20200109182043.jpg]

It seems the o-rings in these gasser pumps don't like the diesel. I pulled some pumps apart and switched out the o-rings for diesel resistant type and it seems fine now. Rings are about 4.7cm od x 3mm:

[Image: 20200109182107.jpg]

Here are the locations of the rings inside the pump:
[Image: 20200115172115.jpg]

And back together with extra crimping:
[Image: 20200115172033.jpg]

Once I got the diesel and oil leaks stopped, I ran the car for awhile and found that the OM606 thermostat was not opening early enough for my comfort. I swapped it out with a OM603 thermostat as the 603 thermostat spring assembly extends a couple CM further into the block than the 606 one, this seems to have resolved that issue. The previous loping appears to have been cured by removing EDS form the pump, so that will stay that way.

I took it around the block a little bit then about a mile on a good paved road to get into some boost, running only about .8bar for testing I can already tell this thing is going to be really fun. Sadly I found the rear brakes were stuck on due to smoke billowing out and the brake fluid escaped, so I will have to swap the good parts over from the 83. It sounds like the guide rods are shot also, luckily those should also swap over from the 83 as I just rebuilt all of that recently.

I am still smiling from the sound of the turbo spooling on this thing, has to be one of my favorite sounds on the planet. I did blow a boost elbow off when I turned it up to 1 bar going back up the hill, so I am going to have to do something about that for running full boost. Worst case I'll have to make stainless pipes with smaller rubber pieces off medium trucks with spring clamps, but that should not be needed for these low boosts under 3 bar, I am hopeful that I was just not tightening the T-clamps enough. I'll try roughing up the edges of the aluminum a little with sandpaper and clamp down harder, hope they hold.

More to come next week, hopefully soon I can get to tuning the transmission and pump.

RE: W126 short body OM606 - awsrock - 01-19-2020

How is the rear axle? Since I last posted, I abandoned my 722.6 plans because I had an axle shaft go bad and got a 2.47 LSD from a 560. With the 722.3 it is not bad. Around town is a bit slower but the highway advantage is great. I picked up about 1-1.5 mpg and have a useable 3rd gear to downshift to at speed.

RE: W126 short body OM606 - wiseman89 - 01-20-2020

Is the car that you swapped the OM606 into a Gas car ? Im surprised you used the fuel pump, to just get my car on the road Im going with no electric pump.

Did you managed to get your speedo and tach working ?

RE: W126 short body OM606 - WSchotty - 02-02-2020

Quote:How is the rear axle? Since I last posted, I abandoned my 722.6 plans because I had an axle shaft go bad and got a 2.47 LSD from a 560. With the 722.3 it is not bad. Around town is a bit slower but the highway advantage is great. I picked up about 1-1.5 mpg and have a useable 3rd gear to downshift to at speed.

The 2.47 seems a bit too low for the 722.6, though I have not fully dialed in the controller or IP yet. I may swap in the 2.82 before I dial in all the shifts just based on my first highway run, I still need to play with timing a bit before I decide. I would really like to keep the 2.47 LSD diffs, as the carrier is different for 2.82, though there are aftermarket LSD units by Wavetrac that will fit the W126 1.3L 2.82 carrier for an another $1K. The first LSD axle I have could not hold both wheels anyway, but found another one that seems like the clutches are better. If I don't go 2.82 I'll swap that one in.

Quote:Is the car that you swapped the OM606 into a Gas car ? Im surprised you used the fuel pump, to just get my car on the road Im going with no electric pump.

Did you managed to get your speedo and tach working ?

No this car was a '91 350SD diesel, I used some gas car parts for the fuel system (strainer, fuel lines, pump/tube mount, pump shield, and pump). Tanks of w126 between gas and diesel cars are the same except for a little plastic baffle in the intake tube that you can drill out rivets on to remove for the larger diesel nozzle. I used electric over mechanical for good fuel supply and backup, I had a similar setup on my last cummins swap and it is nice to have redundancy. When my electric pump (or electrical system!) would go out I could still drive (reduced power) on the mechanical. Hopefully this one works the same way. There is a very similar bosch pump used in the ford 7.3L expeditions which I'll go to if these gas ones start dying, but so far with the good o-rings it is running fine. All gauges are working, as well as AC with the EDS system still intact mostly. The only features I removed from EDS were the disengagement of AC compressor when floored and increase of idle when AC pump engaged as that circuit was not happy about all of it's missing EGR sensors/actuators.

Idle after warm:

[Image: 20200121111359.jpg]

Last week I stripped down the parts car the rest of the way and sent it to it's new home:

[Image: 20200122163907.jpg]

A pile of leftovers:

[Image: 20200123125851.jpg]

And got some wax on the body:

[Image: 20200130140803.jpg]

Once it is shined up that bumper gap isn't so bad. I still have to get some wheels and tires on there and put some 2.5/5% on the windows.

Currently I am waiting on a used A-B tester to show up as I want to get the timing perfect. I set it at 8 using the eyeball method, but seems way too advanced. I am smoking around everywhere, I tried dialing the ALDA way back but went too far and it wouldn't start cold, so on the edge of that adjustment and still have enough smoke that I will get tickets here. (Yes, they passed a law here for diesels smoking too much, 100-200$ per ticket) Only thing I can think of is too much advance on the pump, will retard it all the way to other limit of Dieselmeken spec 10 ATDC and see how it goes. Injectors are already set to 150 bar. It is very loud at idle also which supports the advanced timing, maybe my eyeball was a couple degrees off and it is running more like 6-7 ATDC. When retarding pump it should also help earlier lighting of the turbo, so this may improve the low RPM 5th gear highway cruising.

RE: W126 short body OM606 - WSchotty - 02-02-2020

One more thing I should mention while I am on here today, the alternator. If you are picking an alternator, make sure it has the ratcheting pulley on it. The one I used from the W140 I-6 car does not, and I can hear it chirping sometimes when fully loaded idle. I think om642 and some others use similar pulley, once I fry this belt I'll post more on sorting that out.

RE: W126 short body OM606 - WSchotty - 04-04-2020

Some updates. I checked timing with the tool, was exactly at 8, so the vision method works perfectly fine. I set it at 10 ATDC and it didn't change much. Still more smoke than would be expected when alda is right on the edge of the car barely starting and barely on it, my new theory is the 2.47 causing high low rpm load combined with poor injector spray quality may be the cause.

[Image: 20200219115422.jpg]

Here is the basic layout of the center console, currently I just have everything kind of sitting in the radio hole, but will someday make that nicer and secure it all. It fits pretty well in there right now, but need to redo the whole console. When I do the sound system and rest of interior I'll deal with this stuff.

[Image: 20200219153432.jpg]

Those extra switches in the tray were from the 83, only the two tiny rockers actually do anything. One is for glow plug and one for hi/low boost. In that car I had a 8" screen in the center console so had to move all the switches down.

So now the plan is to put the original 2.82 350SDL differential back in, weld on a downturn tip for exhaust (soot on ass), and figure out what to do about the injectors. I had the local Bosch shop set these up for 150 bar with new nozzles, but it is starting to feel some light missing when cold, could be bad spray pattern already. After a couple thousand miles they are also still really loud, so may not be set to 150 or have slipped way down since setting up. I'd like to have new ones built with good nozzles and well balanced to see if that helps. Anybody know of a good injector builder? What are the best nozzles, I was thinking of Firad? If I can't find somebody to build them I'll get the equipment and do it myself, but then will have to find a good place for the shims.

RE: W126 short body OM606 - WSchotty - 08-18-2020

Well, some more time has passed, it is time for the latest updates on this one.

The alternator pulley on the non overrun alternator can be swapped without issue. I used INA with reference 602-150-00-60.

[Image: 20200422154432.jpg]

One thing is the difference in size, this changed my belt to a longer size. Right now I put on number 4060850 and it is working with no issue, but I may go one size smaller if it starts slipping.

[Image: 20200422154530.jpg]

After some more tuning of the transmission and driving, I want much higher final gear. The stock LSD cooked the clutches already, so no concern about trying to preserve those carriers. Wavetrac makes a carrier that fits the 210mm differential, but the highest ratio for that is 3.06. I think this will be ok, I put a small case 2.88 from a 300SDL to see how it feels, this was the closest to 3.06 I had:
[Image: 20200702104424.jpg]

Note the precision differential jig and contaminate free work zone.

At cruising in fifth, but not sure if the torque converter is locked or not here, more on that later:
[Image: 20200723135500.jpg]

It appears there were 210mm 3.06 differentials in 70s SLs, and w124 300E/CEs at least. I pulled one from a '74 450SL, but I nicked the pinion with the torch trying to get the pinion nut off, so need to find another one. I'd also like to find a W126 case that has multiple sensors so I can use an external speed for the OLE controller. I think the ASR cars had more than one, but still need to research that. If not, maybe I can pull signal from the single ABS one, but want to keep stock ABS working with it. Controller is working ok with internal, but want best reliability on this car.

[Image: 20200805133606.jpg]

Part numbers on that one were:

Pinion: 116 353 25 10 - 3.06
Ring: 116 353 25 12 -3.06

I changed the exhaust tip, I may also try to find a better 3" muffler instead of this w220 one, though it seems ok at 2 bar. I haven't turned up the boost yet, but this thing is small inside:
[Image: 20200702133105.jpg]

I like that it is quiet, I have 3" on the om642 and it had bad drone even with a huge straight through muffler. I ended up putting one of the w220 s55 resonators on the end of that one to stop the problem, not like it is flowing enough for that to restrict it. This one likely needs a real 3" resonator if I put a 3" muffler on there.

I had some saga with the transmission, I think the junk yard e320 torque converter was not a great idea. The temperature is way too hot, with spikes to 120c, and some strange issues with shifting and stalling the engine at stops. I found Florida Torque Converter builds better versions, they built one for me with 1800-1900 stall, triple clutches, and HD bearings:
[Image: newtrq.jpg]

Now it is time to swap it out, I just hope the AMG transmission didn't get damaged or catch shrapnel from the bad converter:
[Image: 20200807082523.jpg]

The stock flexdisks and 2 driveshaft carrier bearings look to be fine so far with some abuse.

For the fuel injectors, I ended up sending some cores to Erik at Dieselmeken for rebuild and balancing. Figured may as well just have the master himself do it instead of botching up another set trying to learn.

Now I just need to finish replacing the torque converter, swap the injectors, set timing back to 10 from 11, and start saving for a LSD carrier, CV axles, and muffler. For the differential I will likely need to find a shop who has the case spreader for these Mercedes diffs, hopefully somebody around here has one, as looking at the threads for those who have built their own seems like a large pain in the ass. I also have a Thermotop-C from another project that never got used, I am thinking about putting it on this car while I have it up on the ramps so I can start it in the winter without a smokeshow.

RE: W126 short body OM606 - WSchotty - 11-02-2020

Latest update time.

The torque converter is swapped, along with valve body. These helped a little with temperatures, but I eventually had to add an additional cooler to keep it below 100C:

Horns were moved behind the bumper on the passenger side:

I tied the OFgear controller to the rear diff ABS sensor for external sensor, and made the cruise control stalk accel/decel into shift up and down for now. I found some paddles that I may add to a non-leather W126 wheel later on, but the cruise stalk is fine for now, just have to be careful when going to signal quickly...

Injectors were swapped with the rebuilt, they helped smooth things out considerably. Still have some nailing, will let them set in a couple thousand miles, might have to retard pump some more. Currently at 10ATDC, might try 11 or 12 if things don't quiet down.

I found the source of my oil leak when I had it up for the transmission, crack right in the middle of the pan. Luckily a fellow forum member nearby had an extra to sell, replaced that to have my first leak free 126.

I added a Thermotop C, really makes for easy starts on cold days at high altitude. When I wired that in, I set it up to energize the climate control system at the fuse block. I did not yet hook up the blower circuit, only the monovalve and aux pump operate to heat the heater core, windshield tray, washer reservoir, and engine. I did this to preserve battery and engine heating time. I'd like to hook up the blower but that may be a bit much. We'll see how much it drains it on the -20f days before I decide on that one.

Welded a mount beside the ABS unit:

Exhaust routing:

Used the small nipple in the fuel pump elbow to feed the Webasto, line fit perfectly in spare slot along the brake/fuel line route.

Unit and added lines:

Here you can see the timer control next to the headlight switch:

Another problem arrived, I saw this being dumped on CL dirt cheap, still deciding what to do with it. Has DSL1 and Ofgear controller, owner said might have a cracked prechamber:

Anybody know this car?

Next big project on the 126 I need to build the differential, the other day passing a slow car I thought my transmission was slipping until I saw the smoke:

I turned it down a bit when I put the snow tires on so I don't destroy them in a season.

Speaking of smoke, it is now as smoke free as I am going to be able to get it with a mechanical pump. Only the transition to boost there is smoke when trying for a fast spool, just have to use the foot control to prevent it. Now that the DSL1 showed up in the w116 I was thinking of having a 7.5/8mm electric pump built eventually and use that in the W126. The mechanical pump and other om606 could go into something fun. The amount of control that Baldur has achieved with the newer pump is very cool.

RE: W126 short body OM606 - WSchotty - 03-05-2022

A short drive video

RE: W126 short body OM606 - WSchotty - 02-04-2023

Time for some new revisions!

Some new 7.5mm EDC artwork has arrived from Dieselmeken:

The teardown has begun tonight:

I'll be using the DSL1 from Baldur's Control Systems, along with a PCS transmission controller. Once that is all in, I'll swap the exhaust manifold with one from the Kangaroos Team, along with a real 3 inch rear muffler. I'm still waiting on the differential shop for the 3.06 gearset, I may need to find another shop as it has been quite some time with no response from them. More to come soon hopefully...

RE: W126 short body OM606 - burgurboy - 10-19-2023

Do you still have the w116? I know a thing or two about that car. It has my old om606 and dsl1 in it ?

RE: W126 short body OM606 - WSchotty - 10-21-2023

I kept all the goodies off the w116 and parted the rest of it out. I did end up finding your build on 4bt, heck of a lot of sweat in that engine! Your swap is awesome!

The engine is going to get built a bit so I have a good engine when this one gets too tired, and the DSL1 is nearly wired up in the w126 now. Haven't had a whole lot of time to work on it this year sadly.

Here are the latest updates while I'm on here:

Pump is in and timed, cut a old cruise control module in half for a mounting point for the trans controller, and tapped into the fuel cooler plate for a extra coolant sensor:

Using a later model canbus shifter from a w210, and a throttle pedal from a w212. I was able to get most of the heavy harness work done last spring:

Multiplexing for cruise control, to actually run cruise control instead of using as a shifter:

Hopefully this winter I can get the rest of the electrical done, then at least drive it a bit before going into the manifold and rear end projects.

RE: W126 short body OM606 - Tomas51 - 10-29-2023

Hey, nice project. Do you count how many hours you already spent on it?

RE: W126 short body OM606 - WSchotty - 11-02-2023

(10-29-2023, 06:14 PM)Tomas51 Hey, nice project. Do you count how many hours you already spent on it?

Thank you.

Actual time working on the car itself, maybe 4-5 weeks total. All the research and parts collection, hell of a long time. This is obviously not a show car, but my driving car so I haven't spent all the extra time to make it perfect and clean, it goes on mud roads and snowpack. I have always worked on my own/family/friends cars, I don't work in the automotive field so I am also learning as I go which can add a lot of time.

RE: W126 short body OM606 - WSchotty - 11-27-2023

All of the wiring is wrapped up:

All terminations crimped and soldered:

Additional relay block:

DSL1 attached:

New looms in battery tray, shifter area:

TCU tucked away:

RE: W126 short body OM606 - WSchotty - 11-27-2023

Interior back together:

These w220 floor mats work pretty well with the w212 pedal. Just a cm or two long where it meets the seat, still usable.

Sounds of the engine:
https://www.youtube.com/watch?v=cIw-IGSjXoA

RE: W126 short body OM606 - Rwd4evr - 02-09-2024

Great build. I have a very similar project I've been gathering for fur a while now. Hope it's working out well. I'm very intrigued by the baldur DSL1. I have a 6 speed for mine though.

RE: W126 short body OM606 - WSchotty - 02-13-2024

Rwd4evr - DSL1 and anything from Baldur is excellent, highly recommend. Manual trans w126 would be absolutely awesome!

It looks like this thread is all hosed up on STD, not seeing a way to edit the posts to fix all the photos yet.
For now here is a backup of this thread:
https://www.benzworld.org/threads/shortbody-om606-build.3116157/

I'll have to redo this one here to fix the pictures or figure out how to edit, I'm on a cellular connection for awhile to it may just not be completely loading.

RE: W126 short body OM606 - WSchotty - 04-20-2024

I added a auxiliary fuel filter and a GSL392 fuel pump, as well as a check valve and another small inline filter for the engine heater. While I had this apart I also swapped the tank strainer back to the diesel version with course mesh, as I didn't want the fine mesh gasoline version to become clogged or inhibit flow during very cold operation. This seems to have cleaned up a air issue in the fuel supply.

[Image: 20240101210052.jpg]

As a solution to some of my signal noise issues and inconsistent engine speed, I changed the flexdisk to a 606 with speed tabs from the 603 plate that I had in there. This will allow a complete separation of the EDS module and DSL1 by using the original om606 speed sensor for the DSL and the flywheel tooth sensor for EDS. I had used the amplified engine speed signal from the EDS computer and there was some noise and varying pulse width that was not ideal. I didn't want to remove the resistor in the DSL1 to be able to see the flywheel tooth sensor while the EDS is still using it, keeping them fully separate seems like a better way.

[Image: 20240408122205.jpg]

Channel 1 (top) is pin 4 of the EDS test block, channel 2 is pin 2. There is some random noise on the line, as well as considerable variation of pulse width.

[Image: Noise.jpg]

While I had to pull the exhaust, I started building a better one.

Kangaroos manifold:
[Image: 20240413174925.jpg]

Stainless tubing, dual exit:
[Image: 20240420190604.jpg]

RE: W126 short body OM606 - WSchotty - 05-14-2024

A much more simple downpipe:

[Image: 20240427172756.jpg]

Support on the transmission bellhousing:

[Image: 20240429170617.jpg]

Upgraded to -6 an oil feed for the turbo:

[Image: 20240429170702.jpg]

And the rest of the system:

[Image: 20240511120942.jpg]

Unassuming from the back:

[Image: rear.jpg]

Now I just have to figure out the ECU tuning, which has been taking me quite awhile to understand and get right. There is still some lower speed engine oscillation that I need to figure out how to eliminate, then I can get into fine tuning of the shifts and all the other little details once it is more stable to drive.

RE: W126 short body OM606 - WSchotty - 06-30-2024

I spent the morning tweaking the idle PID values to get idle mostly stable so I could recover and recharge the AC with the correct amount of R134a and some UV dye now that it is finally starting to get warm around here. I still have quite a lot of work to do tuning wise on both the engine and transmission, this exhaust does sound interesting from the rear mount gopro perspective. In the cabin it is very quiet.

Walk around:
https://youtu.be/1SX9oZNNN0w?si=dwfhqbheOTrxt4Ub

Driving:
https://youtu.be/Y0uLEYDRz0o?si=QodAZ4OqkfVMlqsG