Differences in m119 motors?

[JC220]

Hi all,

My recent project 1995140 S500 coupe has damaged bores so therefore I am needing to buy a good used m119 5.0 motor.

Can I tap into the minds of the board here please and discuss the differences between different m119 motors?

M119.970, m119.974 etc what is compatible- and is any a particular advantage?

I understand it must be a LH injected motor with a fuel rail. And the Sump pans can vary but I could swap my old one if needed.

My w140 has a m119.970 motor with the plastic oiler tubes and updated belt tensioner. Will a r129 engine with no distributer caps on the front be compatible? Eg swap over the upper timing covers?

Thanks in advance

 

[JC220]

For example I am looking at a 1992 S500 w140 donor with low miles. It should therefore have the correct sump and metal oiler tubes.

I would then swap my later timing cover onto it and refresh all seals etc with free access.

 

[gsxr]

.974 (W124) and .972 (R129) are basically identical, I think the only difference is the ETA has a different cable length.

.970 (140) has different exhaust manifolds, upper+lower oil pan, and oil pump/pickup. You can swap all this stuff but it's a PITA.

Make sure the donor is a "late" M119... in USA, this means 1993-95 model year. Identifiers are a 6-rib serpentine belt and spring-loaded tensioner. I don't know the break point in Europe but a photo of the engine front should identify the belt/tensioner type. Most of the internals are different too. Also make sure the donor is not a late engine with ME injection (1996-up USA model year), this will require a bunch more parts to be swapped... it can be done, but it's far more work.

EDIT: I see you are looking at a 1992 S500 motor. Yes, this will be plug+play, if you swap all the accessories/brackets/etc on the front; plus the ETA. If the timing cover has a mounting boss for the late tensioner, it can be drilled & tapped; no need to swap the timing cover (MISERABLE job). You lose the internal updates found on 93-up models but that's probably not a big deal. This would be a good alternative if you can't find a .970 engine from a 93-95 140.

 

[JC220]

Thankyou for that Dave! Yes the only motor I can find available in Ireland appears to be a 1992 vintage m119.970 from a w140 saloon. So I will swap over all of my ancillaries from my 1995 motor.

As I understand it this 1992 motor will have metal oiler tubes, larger bearings and closed deck block - among other changes. IMO the later changes brought by MB were cost saving measures more than anything else. Besides I also do not care at all about fuel economy - if it really makes a real world difference at all! When I get it running again Dave I will be in touch for another eprom chip BTW.

Here is some info I found which was most relevant - see also the document linked by Dave (GSXR)

Assuming we're talking about 1992-1995 only... they had different exhaust manifolds, oil pan/sump, and oil pump location. Same power output.




Same differences... 1992 was rated 322hp (SAE net), 1993-up was rated 315hp. This was because the WOT enrichment was eliminated from the computer programming starting in 1993. The actual power loss was more than 7hp, but MB partially made up for it by reducing the weight of the pistons and valvetrain, primarily for fuel economy, but this freed up a little power as well. Click here for details on the 1993 changes, which applied to all M119's regardless of displacement or chassis.

A host of changes were made to the M119 in what corresponded to the USA model year '93. Almost all of these changes were made to increase fuel mileage in the European tests, most especially in the 140. Almost everyone is familiar with the much fetishized elimination of wide-open throttle enrichment. Some are also familiar with the thinner, lower friction belt drive, but most people do not realize that the complete list of changes was extensive, encompassing almost all of the internal moving parts of the engine.

These changes are possibly relevant to your question about the valve guides:
The outside diameter of the valve guides was reduced by 1mm to 12.5mm. The valve springs were changed to a conical design, and the spring force was reduced on the 4.2 L engines. Camshaft lift was reduced, and overall valve timing was modified. The weight of the bucket tappets was reduced from 82g to 64g. The WIS notes that "sintered metal valve guides" were "phased-in 1993." I know of no problem with any M119 valve arrangement. I suppose it is possible that the material was actually changed when the diameter was reduced, but I don't know for sure...

Thanks for the updates. I suppose it's possible to do enough research to gather together a list of the sum-total of the changes - perhaps a research project for someone, some day.

I think a second/dual purpose for many of the changes, in addition to increased efficiency/mileage, was cost reduction of production and componentry as part of a general cost reduction program in that time frame for the W140 and W124 models. There were made other, engine and non-drivetrain changes made (the metal to plastic oiler tubes being a "much fetishized" one) whose goal was more cost reduction than anything.

I have always said that there was a tangible difference in feel/materials/quality between my 1992 300TE wagon and the two 1995 wagons I owned. It was subtle, and in many cases made up for by the (IMHO better) M104 engine vs. M103, but it was definitely there.

I have NOT been able to discern a distinct quality/materials difference in the early vs. later 500Es although perhaps a case could be made. There are many small touches that the 500Es had that were phased out, that portended a desire to reduce parts/production cost. One such thing would be the silver lettering and silver MB star on the top of the airbox on the earlier cars. In 1993, the silver letters and MB star were phased out to an unpainted (i.e. cheaper) setup.

Cheers,
Gerry

No doubt, cost reduction drove many of the changes, most notably the oil tubes (grrr...)

Yes, I believe GSXR has photos on his site, but I can’t access them right now.

Basically the area directly around the cylinder bores is open on an “open deck” block, whereas it’s car closed/solid on a closed deck block. There are more “openings” on the top of the open-deck block where the head gasket rests.

IIRC there are different head gaskets for the M11levers 9 versions, as well.

I believe the move to open-deck blocks was a subtle thing they did to reduce production cost. There is no performance or operating temp differential between the two versions

Here are photos of M119 closed- and open-deck blocks:

CLOSED-DECK BLOCK




OPEN-DECK BLOCK (courtesy of GSXR)

 

[JC220]

Another question - I will be hoarding ALL m119 re-usable parts from my 1995 motor. For my 1992 500E, the 1995 S500 and any other m119 models I pick up along the way in the coming years.

Do we know if the Cylinder heads from a 1995 late open deck m119 will fit a early closed deck block? (With the appropriate head gasket for the engine block construction)​

 

[gsxr]

As I understand it this 1992 motor will have metal oiler tubes, larger bearings and closed deck block - among other changes. IMO the later changes brought by MB were cost saving measures more than anything else. Besides I also do not care at all about fuel economy - if it really makes a real world difference at all!

Joe, I'm not aware of any "cost savings" measures other than the plastic oil tubes. Closed deck block was phased in around late 1993 calendar year. I really hate the early coolant drains on the early blocks. The info you found above summarizes all the differences. You are correct, from the driver seat, you won't notice any change between early vs late motors.

Do we know if the Cylinder heads from a 1995 late open deck m119 will fit a early closed deck block? (With the appropriate head gasket for the engine block construction)

THAT is a good question. It appears the heads may be interchangeable, unless the engine is a very early build (circa 1991), in which case the bolt pattern is different for the timing cover/head/gasket on one side.

 

[JC220]

Also make sure the donor is not a late engine with ME injection (1996-up USA model year), this will require a bunch more parts to be swapped... it can be done, but it's far more work.

Sorry to be a pain - It seems that my choices are a little limited at present between early 1992 production motors and a 1997 S500 engine which will have the coil packs etc.

Is this a huge job? Aka is the upper timing and cam covers the main components requiring changing over to adopt to my 1995 distributor cap m119?

The main advantage I guess with the 1997 motor is this one is low mileage also and will have the late internals like my 1995 S500 would have. Serpintine belt drives will be the same too.

 

[gsxr]

Is this a huge job? Aka is the upper timing and cam covers the main components requiring changing over to adopt to my 1995 distributor cap m119?

I've never done this, but you have to replace the intake manifold, both valve covers, front head covers, all four camshaft sprockets, distributors/wires, ETA/MAF, and possibly some other stuff.

 

[JC220]

In an unexpected turn of events I have also purchased another m119 engine and gearbox. I am told it is a 1996 year car it came from so if that is the case it might be the newest form of injection etc and distributer less. The transmission is included so I guess most likely 722.3 but might also be a 722.6.

Basically was offered it at a decent price so it wont hurt to have a spare 5L m119 & gearbox tucked away. Indeed it does also leave me with 2x options for my S500 Coupe situation. Perhaps the leak down test results on both engines will be a deciding factor. And it might be nice to keep a closed deck block aside and put the later internal m119 back into the S500 coupe... at least I have options now always a good thing!

 

[gsxr]

Joe, all the M119.98x (coil-on-plug, ME 1.0 injection) engines came with the electronic five-speed 722.6 gearbox. Rumor is the early 722.6 boxes were not all that great as they had some design issues, which were sorted out a few years into production. Didn't you already go down that road with a previous restoration, updating the early 722.6 internals?

You can swap in the .98x engine into the LH-injected S500, if you swap all the stuff which bolts to the cylinder heads, and the cam sprockets (or, entire cams + sprockets). This was discussed previously. You'd need to check the chain rails on the late motor as well.