V8 in a W123??

[blkchambers]

I've been consdering for some time putting an MB V8 into a W123. Anyone know of this having been done before, and what the best V8 choice is? I don't want any of computer participation, so too late of a V8 is out of the question. Don't mind fuel injection.
Input anyone??
Bob

[awa]

Dear Bob:

My cousin installed a 1971 M-B 3.5 V-8 engine and transmission in a 1978 240D mostly using M-B parts. This was a great car, fast, stable, fun to drive - 0 to 60 in 5.9 sec. I purchased the car and drove it for a number of years. Unfortunately the car was destroyed by a teenager who had his license for just 3 months, at night with a car full of teenagers.

I still have the engine and transmission with many of the custom parts needed for this engine graft. If I were 30 years younger, I would definately build up another one just like it.

I will not be back on line until after the Thanksgiving holiday, so if you have any questions, feel free to contact me after 11/28/04.

Art Aseltine
awa@lostsierra.net

[Tom Hanson]

Any MB V8 will require some type of computer assistance. A 3.5 from 1970-71 would be great. You'll need the trans from the same car to do it properly and easily. I've seen it done. Bill Matthews at the M-Class plant did one many years ago.

[blkchambers]

How about a 4.5?? They seem to be alot more common. (Easy to find) Or even a 5.0?
Bob

[Robby Ackerman]

Chuck Stanford has a Corvette engine in his 123 wagon. Chuck, send me a picture of your wagon.

[blkchambers]

Corvette engine may be faster, more reliable, cheaper, easier to maintain, easier to find parts, BUT .......... Nah!

[Robby Ackerman]

Oh, YES. You can pull out into traffic anytime you like, and it sounds oh so nice.

[Tom Hanson]

What the heck, try to stuff a MB 6.9 liter V8 in it. What a machine that would be..

[blkchambers]

Well,Tom, as I mentioned to AWA, the 3.5's may be nice, but they're not very common. Do most of the V8's have the same size block? I'm just wondering if I get a 5.0, or even a 5.6, will it even fit into the hole? How late can I go without having the computer want to control everything from the radio to the dome light?
I don't mind electronic fuel injection, or even ignition control, but that's about it. I have no way to troubleshoot these computerized monstrosities, so want to keep it as simple as possible.

[Unregistered]

hello,
check out this link.
there is my w 123 friend from germany.
he had an 230 E with a 3.5 engine.but he will update with an 5.0
MB engine.

http://www.mp3xxx.de/1112/1165.html

cu stryker from germany
mercedesw123@aol.com

[blkchambers]

Nice photos....Sure wish I could read the information. Is your friend saying that a 5.0 or 5.6 will actually fit in the w123 engine bay, without cutting structural parts?
Bob

[blkchambers]

I've " chatted" with a gent in Ireland who also sent me a Photo of a W123 AMG! It had a 5.0. so apparently, they do work. I've found an '84 500SEL with bad chassis rust, but engine seems okay. The price is right. A compression check is forthcoming. In any case, it'll be a long project. I'll keep you all posted! Lots to do.
Bob

[Grey Ghost]

I wouldn't make such a swap for all the tea in China...how would my dogs know I was coming around the bend?

[blkchambers]

If this was my daily driver, I wouldn't be either. I've only put about 7000 miles on it in the last nearly three years. The V8 would be alot more fun! The Turbo diesel certainly will not go to waste. I'll put it into a a small custom pickup, and then use that as my driver when I retire in a few years.
By the way, how much tea is there in China??
Bob

[mtupower]

I had the same idea a bit back and found a 380 ome one had put into a w123 wagon. You'll need a 560 if you want to keep the sls, and all the 81-91 V-8's have the same footprint, and have very very little computer stuffs. BTW AMG made a w123 wagon with a 560 I believe, but pushed it to have 6.0 liters- a 600 TE. GET out the way!!!!!

[blkchambers]

Operation V8 is underway. Compression check is done, the motor seems fine. Fluids are clear, it starts immediately, idles normally. Trans shifts smoothly.
Disassembly of the rusty 500SEL is started. MAN there's alot of wires!!
The slowest part so far is separating the wires that I don't need, which go into the same bundles as the wires I do need. Basically, anything that leads to the motor or trans is carefully traced back to its source, and saved.

[mtupower]

Geez I gott see this, or help at least... I travel over to Parrish quite often.

[blkchambers]

It is still a way off before I get past the disassembly. Tracing all the wires is time consuming. When I do put them in the W123, they will be bundled completely separately.
e-mail me. blkchambers@verizon.net
Bob

[blkchambers]

As expected, removal of the wiring is a major undertaking. Basically, I started at the engine, and traced every wire that was connected, carefully slit open the bundles, and traced them to their source. Where wires needed to be cut, (typically at the relays) they were cut close to the relay, but not so close that they were not able to be identified as to which pin they were to be re-soldered to later. They were carefully labled where they originated and where they went. Where wires (in the same bundles) were confirmed to be irrelevent, they were removed and discarded into a "just in case" box. There are alot of relays, of course, and MB's great schematics will become invaluable when reassembly starts. So far, the only surprise has been the electronic speedo, but I've been told that if I change the tailcone of the trans,( from an older model), I can go back to the mechanical speedo. The drive units are different.
The next step is to do a cursory cleaning, pull the 300 out, and do a test fit to confirm that it will actually fit without cutting any structure, and measure for the mounts, and any special hardware that needs to be custom made. Then out it comes again to detail the motor, replace anything that will be more easily replaced out than in, and bead blast, and paint ugly parts.
Next phase will start around 2 weekends from now, as I will have use of the neighbors garage. I've removed everything from the SEL that I could possibly need, in preparation of towing off the hulk. Space is critical, and I won't be able to keep the SEL around in case I forgot something.

[blkchambers]

Well the 500 motor is finally out of the SEL, and has had its cursory pressure wash, so I'm not wallowing in grease during the test fit. When the wrecker came to get his "free Mercedes" there was a hint of disappointment at how little was left. They'll probably take it directly to the chusher! It was a shell and a windshield! I did warn them, but I don't think they took me serioulsy. I'd have taken the windshield out too, but have never successfully removed one without damaging it. Anything else I removed either to sell, and offset some of my expenses, or just in case I need it. I didn't have the space to keep the whole car, and had to be sure I got what I needed.
I drove my 300 CD today about 100 miles to use up most of the diesel that was left, so I only spill a little on the garage floor as I try to drain it, instead of alot.
The rest of this week gets spent organizing the mess, and cleaning up (gotta keep Mama happy!) Next week will be the removal of the diesel and test fit of the V8. After I ensure all is right, and measure for motor mounts, etc., out she comes again for serious cleaning, bead blasting and powder coating parts. New belts, hoses, and tune up parts. Probably a timing chain. Anything that'll be easier out than in.
The saga continues...

[blkchambers]

The test fit went almost as expected. So far no nasty surprises. It goes into the bay, obviously tighter than the 300D, (and I even closed the hood! ) It has about 1/2 ' between each manifold and the respective shock tower. It fits well with the steering box, lower cross member and the tie rod.
The motor mounts on the W123 are actually 2" farther apart that the ones on the W126 (21 1/2" / 19 1/2"), so there will not have to be any special supports made, only a 1" spacer between the engine block and the M117 supports. That is easier than expected. It appears that the rear mount from the 300D trans can be used with minor modification.
The crossover pipe between the left and right exhaust manifolds interfered with the stabilizer bar, so had to be removed. A custom dual exhaust is in the coupe's future. (cool!) The right motor shock should line up okay with the mount for the W123, but the left will not. (The M117's left shock is in front of the mount, the OM617's is behind) It appears that the drive shaft will have to be lengthened about 2".

[blkchambers]

As it turns out, the one inch spacers located the motor a bit too far to the right, so I changed them to a 1 1/4" on the right, and a 3/4" on the left. The motor is now perfectly centered between the shock towers . I also tapped new holes into the spacers (1/2" behind the originals) to move the motor 1/2" forward. It now has the same 8 1/2" from the distributor cap to the upper radiator support as the SEL had.
I thought I'd have to have a custom radiator made, but the (27 1/2" wide) SEL radiator fit with minor mod to the sheetmetal to the left and right of it. It is about out 1' taller than the OM617 radiator, but that does not affect anything. The hood still closes. I'd much prefer to keep standard parts to make future replacement simpler.
The stock M117 exhaust manifolds fit, although the on the right side, the passenger floor, at the corner, as it rounds back into the trans tunnel, had to be pushed back about an inch to make room for the manifold and a heat shield. This creates a barely noticable bump in the upper left corner of the passenger floor.
The M117 must be quite a bit lighter than the OM617 diesel. The car sits about 2" higher than it did with the diesel, although there are still parts to install. I have a spare set of 240D springs I'll try. If they don't bring it down, Eibach will be on my shopping list, for a custom set of springs.
Overall, I am very satisfied with the fit. Kinda makes me wonder why MB didn't do this. The motor has now been removed for engine and bay detailing. Wiring will start soon thereafter.

[blkchambers]

Engine bay cleanup and painting is done. Things are going back together nicely. I decided to use the brake booster/master cylinder from the SEL. It is about an inch smaller in diameter,and thus provides better clearance from the exhaust manifold. It is quite a bit larger though, and according to the tech data, should provide about 30% more braking power. It stuck farther forward, so the lines had to be bent into position to fit. No kinks or cracks. The front one needed to be loosed from its clamp, and stretched a bit more than the other two. Back two were easy. The SEL exhaust manifold heat shields were modified to fit the W123. Fortunately, they are soft aluminum, and very workable.
Nothing goes back in without a thorough cleaning. Brackets & such that were once cad plated, if too rusty, are bead blasted, and painted. Not original, but if I started to replace everything, I'd soon approach the budget of some third world countries!
Engine cleanup is next. All brackets and pulleys come off for clean up. If the W123 compressor fits on the 500 bracket, I'll use it, so I can retain all the W123 A/C hoses. It is smaller than the SEL compressor, as it has considerably smaller an area to cool down. Ditto for the alternator, although the SEL alternator is an 80 amp, while the 300D is a 65 amp. A little research here...
It appears from the outside at least, that the tranny tailcone is the same, and should swap over, so I can retain the mechanical speedo from the W123.
Progress. Baby steps for now, but progress. I only have about a day and a half a week to devote to it now.

[cbbemce]

blkchambers,

I have a '75 450SE with less than 100k original miles on engine & transmission. I would sell the entire car, or would part it out if you are interested. Runs great and shifts perfectly.

Thanks,

Chuck

1985 300D turbo

[blkchambers]

Thanks for the offer Chuck, but I already have the motor and trans. Barely have room in the garage for what I do have!
BTW, I referred to the clearance between the W126 brake booster and the exhaust manifold, and it should have been the booster and the Valve cover!
BC

[blkchambers]

The first thing I took out of the SEL for whatever unknown reason, was the instrument cluster. I immediately hit my first speedbump when I found the electronic speedometer. The gauge would not fit the W123 cluster. So...

The tailcone from the 300D trans and the one from the 500 trans were swapped! There is a drive gear inside that needed to be swapped too, but, bottom line is that the W123 cluster is kept, and mechanical speedo will work! I bought a 140 MPH unit on ebay. Not the 160 unit that came on most V8's, but I've never even hit 140, and don't plan to.

Also, if they'll hold up, I'm keeping the 3:07 diff that is in the W123 already. Should keep the speedo accurate, and give LOTS of off the line ooomph!

[blkchambers]

With the engine bay cleaned and painted, and new heat barriers installed where the exhaust manifolds are too close to my (and my passenger's) shoes, & the rubber steering linkage, the engine is ready for final installation. The LH motor mount had to be shimmed to raise it 1/4" to level the motor out, as the motor mount spacer being wider on the RH side tended to lift that side, as it moved it farther left.
Honestly, I'll be very pleased and surprised if it really works out that I don't have to pull it out for anything else, but so far, I can't think of what.
Soon, the W126 radiator goes to the shop to ensure it'll survive. Then I'll contact a custom exhaust shop to make sure I'm on the right track there. Custom headers are still not out of the question. Headers and a better breathing intake system should increase power at a minimal cost, and no reliability loss.
Wiring comes next. EEEEK! Hopefully, I was meticulous enough in disassembly of the SEL harness, and labled all I needed, that it goes back smoothly. Since the engine compartment is smaller in the W123, I may have to get creative in locating some of the controls, and hopefully the wiring will be long enouge to reach their destinations without excessive splicing.

[blkchambers]

Fuel pump from the 126 fit nicely near the tank. Holes were actually pre-drilled in the frame for the bracket, I presume that the 280 gas motor used the same setup. New hoses and rubber mounts were a no brainer. Back seat and passenger side carpets had to come out for installation of wiring.

Drive shaft is out now. The rear shaft "half" is the same length on the 300CD and the 500SEL. The 300CD rear shaft diameter was surprisingly larger than the SEL. It'll be used. The front section is obviously longer on the SEL, but the same diameter. It goes to the machine shop soon to be shortened and balanced. It'll then be attached to the CD rear.

I'v been putting off the major wiring, but can't much longer. Soon...

[blkchambers]

The battery tray from the SEL was used, as the longer diesel tray from the 123 interfered with the valve cover. The forward support arm on the tray had to be drilled off at the spot welds and reattached to fit.
Of the three relays necessary from the SEL, two (relays G & I) will fit in the existing relay box. Being the consumate packrat, I had two sockets from an old 123 parts car, and they slipped nicely into place. I just have to ensure the right pins are used when the wires are soldered into place. The fuel pump relay will fit behind this location in a fabricated box to shelter it from moisture & heat.
The Idle speed control will fit in another fabricated box next to the battery. The wiring is slow going, as the routing and placement of components is figured out, mostly by trial and error. I don't want to end up with a bunch of crimped on connectors and splices. That's where future broken circuits are most likely to occur. It still needs to look as much as possible like MB did this, when it's all done.

[blkchambers]

I found a RH exhaust manifold on ebay from a 380SL, and the outlet curved down at a sharper angle than the w126 manifold providing the needed clearance. I'll use the 500's LH manifold, and have an exhaust shop go from there to a custom connector to the turbo diesel's exhaust system. It's much larger than the 500SEL's and will suffice until the car is up and running well. Then I'll splurge on a custom dual if it in needed.
Front driveshaft section is back from the shop, with a new bushing . The u-joint is bad in the rear section, so the entire unit will have to be sent off to get refitted and rebalanced! Still don't understand the logic in unreplacable u-joints.
About 1/3 of the wiring is done. The original shop manual has a superb diagram of the engine wiring, easing reinstallation.

[blkchambers]

When putting the driveshaft together, I found that the transmission tailshaft yoke and flex disc are larger for the 500 so had to be used. Changed both, and in doing so had to change the nut and o-ring on the tailshaft. A little more wiring in the area too, as the harness on the 500's trans differed from the 300d's (naturally) Also drilled through the tunnel to route the O-2 sensor's wire. Trans is ready to be raised back in for the final time, along with new filter and gasket.
As soon as the exhaust manifolds come back from the ceramic coater, they'll get installed with new gaskets, and the motor bolted in for the final time. Then, its all downhill. A bit more wiring, A/C work, put in all new hoses and belts, and cross fingers..........
Sounds like next week, but realistically with the time I'm able to devote, still a few months away

[blkchambers]

Just got the exhaust manifolds back from the ceramic coaters (Jet Coat in Pascagula Mississippi), and they look great! Almost like chrome, but of course it is covering a porous cast iron texture. They'll go in soon, with new nuts, and hopefully the motor is in for good! Then I can start hooking up hoses, etc.
There's still a "bundle" of wiring to finish, but I DO see the light at the end of the tunnel.

[blkchambers]

Have almost a full day in fitting the Shift linkage rod of all things! Stock (SEL) rod was cut about 5", and threaded. That was easy enough, BUT, since the larger flex disc was used for the bigger motor, it left about 1" clearance for the rod to pass. With every test fit, the trans had to be lowered again to access the clip. If it cleared the disc in park, it'd rub in low gear, or vice-versa. Finally with the right combination of bends in the rod, and cutting 2 small pieces of the rubber noise deadener away for clearance, voila! Spent the rest of the day connecting hoses, throttle linkage, starter etc.

[pch2021]

*applaudes*

I am quite impressed that you have finished this task!

I hope its faster than the turbodiesel.

[blkchambers]

Not done yet, but I can see the light! Still more wiring, driveshaft, exhaust, AC work.
You're reasonably close, Stop in and see it!
Bob

[MBZ300CD]

Get through the junk to get to "coupe's" V8...

http://www.w123-world.org/showthread.php?t=136&page=2&pp=15&highlight=v8

:cool:

[blkchambers]

Nice car, I've seen it before on the Benzworld site. Still looking for a similar ground effects kit for mine.

Wiring is painfully slow. Sometimes it takes a day or more just to trace one minor system. I'm trying to use the existing wiring in the car as much as possible, and when the schematic shows a direct route for a wire from one component to another, it ain't necessarily so in the car. They frequently disappear into the black hole of a huge bundle into the abyss of the underdash. I REALLY don't want to just clip wires off and have dead ends laying about, because someday I may have to actually troubleshoot it! I'm using the proper color whenever possible to extend wires for the same reason. I still only have about a day a week to devote, so it'll be a while.

Driveshaft came back from the shop (Driveshaft Specialists). They shipped the wrong one. Then the right one came back, and it was too long! It'll be right sooner or later. Despite the errors, they've been very apologetic and cooprative to work with.

[blkchambers]

Finally had to break down and remove the dash pad, so as to trace some mystery wires, and remove some unneeded ones. I pulled my hair out long enough, finding wires disappear into the abyss. The schematics typically show a wire straight from one component to another, and don't show the abyss!
Now it's moving along. There are more wires done than need to be done! Still need more time to devote, but that's what makes it a project, I guess. It gets done between work, and honey-do's.

[blkchambers]

Drive shaft FINALLY back from Driveshaft Specialists, and FINALLY fits properly! Wiring still coming along, and is nearing about 80%. Soon the custom exhaust. I think I've got a lineup on a fairly new 280CE dual exhaust from a wreck, at a good price, so the custom pipe will only have to go from the exh. manifolds to the pipe. Still need to wire the starter, alternator, lambda relay, and a few other minor circuits.
I think as a precaution, I'm gonna pull the fuel tank and clean it out. I'm kinda concerned about algae from the diesel, and any 22 year old "yuck" getting into the gasoline injection system. It'll be a pain to get it out, but probably alot less than cleaning out a fouled fuel system!
I need to find 4 bolts that join the exhaust manifold halves for the 5.0. Very odd size (M7x1.0x 30mm) MB sells a an entire clamp kit ($75 /side) Does $150 for 4 little bolts seem a bit extreme to anyone else? Anyone have a couple spares? If it comes down to it, I'll drill the captured nuts out and tap them for 8mm bolts, though I'd prefer the stock size.
blkchambers@verizon.net

[VLayton]

Some hard-core fastener specialist could possibly deliver that odd size, I often buy 8.8 and higher hardware in bulk from a local supplier. It does me good to know the pitch and such, but they still don't have everything, I'm sure I could find a bigger supplier with more options. Certain bolts I insist on getting from my dealer such as caliper bolts, but they aren't $37.50 either!

I enjoy observing your ambitious project, and respect you for not putting a Chevey 350 in it or the like.

I don't know which bothers me more, a Chevy motor in a W123 or when someone buys a 1980 300SD to put it's motor into their 1947 F150 restoration.

[blkchambers]

With as much care I've taken to keep this as "genuinely" MB as practical, you know what irks ME more. Besides, the next project IS a custom "Mercedes Pickup" with a 300D!
I knew an old gent in Louisville that put a 240D in a AMC Gremlin! It was a better car than AMC made!

[Panzerguy]

blkchambers..............I have read your Post's on the 123 Coupe conversion with much interest..........as I have a 123 4D , 114 Coupe, 115 4D , I also have a 3.8 MB V8 from a 380SL that just happens to be laying around not being used.......
Question......... as the 114/115 seem to have similar engine compartment dim's to the 123's.. Do you think an MB V8 would fit.. I realy dont want to use Ford or Chevy small block or V6 in any of these cars. I like the idea of a RETRO fit "AMG"
classic 114 Coupe or a" SLEEPER AMG SEDAN " ......... Any thoughts...........

Thank's for the Post's on Your work so far......Looking forward to seeing the finished product of Your project.

Panzerguy.........
1967 W109 300SEL 3.0L 6Cyl.
1970 W114 250C 2.8L 6Cyl.
1972 W115 220 2.2L 4Cyl.
1975 W115 300D 3.0L 5Cyl.
1977 W123 240D 2.4L 4Cyl
1987 W126 420SEL 4.2L V8

[blkchambers]

sorry about the delayed response, I'm out of town on vacation. Will be back in a few days. Not sure if the 115 chassis is similar or not, but when you get back home, I can provide you with any dimensions you want.
You're two steps ahead of the game with the 380 from the SL. First, the RH exhaust manifold should fit without any issues, as it angles down sharper than the SE/SEL manifold. I bought a RH manifold from an SL to fit.
Secondly, the 380 deck height supposed to be a bit lower than the 500/560, even though the 500 still fits in the 123.

[blkchambers]

Car was taken to the exhaust shop for the week that I was gone on vacation, and I hoped to get it back upon my return today, so as soon as I finished my wiring, I'd be able to fire it up. As it turned out, since I wanted it made from stainless, he had to order the tubing, and just today got into his shop. His materials normally come from Mississippi, and I presume that things are still recovering there, and delivery took longer than anticipated.
Best laid plans.........
Guess I now have time for those much procrastinated honeydos!

[my_w123]

Hi blkchambers,

how is the project going these days? Did you finish your honey dos?

Do you have any pictures?

Best regards.

[blkchambers]

Unbelievably, the car still resides at the exhaust shop. Nearly nine weeks! I didn't know it at the time, but it was a project that he (like me at home) gets to in his spare time, around the "real work" that keeps the shop open.
That being said, I saw the abortion of a part that one of the other "reputable" exhaust shops in the area came up with as a solution to this special need, and it was UG-LY, and unusable. Other shops wouldn't touch it. The problem is the VERY restricted space behind the motor where the LH manifold turns inboard behind the motor, instead of down, and the sharp down angle that the pipe needs to make to clear the throttle linkage, and other parts. Through much prompting this "artiste" machined a fitting to weld to the stainless exhaust tubing, and clamp to the manifold. It is a work of art, and flows with no sharp (hot spot) angles. I only wish it was a 1 week work instead of a 9 weeker! It still needs to be joined to the other side, but the rest is easy. Hopefully, I should have it back soon, and then try to remember where I left off!
So bottom line is, little else has been done to the car over the last 2 months, except to find and restore 2 euro bumpers. I've also located a set of front and side spoilers, and they should arrive soon. Still need a rear one.

[blkchambers]

OKAY!!!!!!! After about ten weeks, I finally got the coupe back from the exhaust shop. In the future, I'll get a time estimate, as well as a cost estimate.
Even though it took so incredibly long, the exhaust system came out.... artful!
Great job, but NOW, I'll have to try to remember where I left off. Man, you can forget alot in that kind of absence!

[engatwork]

Post a pic if you get a chance.

One of the strangest conversions I saw was a the Pull A Parts place in Atlanta. It was a 126 300SD with an in-line six cylinder in it. I could not tell the make six cylinder but I believe it was a Ford because of the color. I had to do a double take when I saw it.

[blkchambers]

No wonder it wound up in the junkyard!
I'll post pics when it's nearing completion. Hate to show it off when it's "half baked"

[Maxbumpo]

One of the strangest conversions I saw was a the Pull A Parts place in Atlanta.

Where can I find this place??

[VLayton]

I'll post pics when it's nearing completion. Hate to show it off when it's "half baked"

I kinda don't want to see it until fully completed with the body kits (I hope you got) on and all painted and shined-up. How about a nice burn-out pic for the W123 chassis forum photo gallery? I expect with the story behind it would make a great exhibit...

[capecustom]

Hi blkchambers,

I've read through your conversion with great interest, I am planning a similar conversion on a 1966 W110 200 (fintail). I am hoping the engone goes in with as little trouble as you have had, as I know the W111 coupe and convertible had a 3.5 V8 fitted as atandard, and this is basically the same body. I am a bit unsure if there are any V8 manual cars arround tho. My 200 is a manual and I want to keep it this way. I can get a 450 engine from an SL but it's an auto. Is there a 5 speed 'box I will be able to use?
If I can get a 5 speed i can keep the 3.92 axle ratio, as I am fitting larger wheels.
I am doing a bit of research, and as far as I can gather the larger brakes from the SL will fit my car.

I am also looking forward to some pics of your car!!!

[blkchambers]

If I made it sound that easy, It was a mistake. I don't regret doing it, but doubt I'd do it again. There is a huge amount of things to do and consider when installing an engine that the foremost car manufacturer in the world never intended to install. It is still not done, as there are still honey-dos, and work and life to delay it. My one year estimate is out the window with the 10 week hiatus at the exhaust shop, and I got it back just in time for my daughter to come home for CHRISTmas holiday from college. There goes another month. (maybe 2 years is a better est.)
Anyway, I know nothing of that body style, or if a 5 speed is available for the V8. With enough money, time and incentive, I'm sure it can be done. I'd be interested in hearing about the progress if you do decide to do it. (LOTS of wiring)

[pch2021]

the 350SL came with a 4 speed.

the torque of the 4.5 engine will shred the little gearbox.

you really should get a 3.5 litre engine. it will make life simple. the efi, however, will not.

one thing you might ewant to consider- a car'b m110 ngine from a 280s.

V8 power, less the weight. you would be much happier.


Bob, if i'm ever down in bradenton, I must see your creation.

[a2aa]

blkchambers
Did you just remove the stablizer bar and left it out or replaced it in a different location? Curious on how you cleared the power steering box-- it's a monster of a unit!! GREAT WORK SIR !! You must have a ton of patience to do this alone. I'm impressed. Can't wait for the pictures!!

[blkchambers]

Stabilizer bar was not removed. It did interfere with the crossover between the exhaust manifolds, so that was removed and custom exhaust work was necessary.
Clearing the steering box was not an issue, but it was necessary to fabricate a heat shield between the exhaust manifold and the rubber flex disc in the steering shaft, and slightly modify the rigid PS lines to the pump.

[blkchambers]

Baby steps!!
Fuel tank was removed, pressure washed to remove any algae growth, drier with compressed air and reinstalled. Just glad there was no evidence of rust inside. Fuel lines were blown out with compressed air to remove residual diesel fuel.
Starter and alternator is now wired up, and fuel supply line is connected, although not through the cooler (AC line fitting). If vapor lock becomes an issue, I'll probably have to redo that.
There's only a few more wires to figure out, and it (hopefully) will be fired up soon. AC system will wait until later, after the car is up and running, as it will need some custom hosed built.

[blkchambers]

The beast actually got started up yesterday! It would , however run only as long as I was willing to stand over the throttle body and pour gas into it! Since this would be most inconvenient on a road trip, I knew I needed to troubleshoot.
With lots of tremendous help from Rex at German Cars of Sarasota, I came to the conclusion that the fuel inlet and the return lines were switched. (NEVER trust the parts manual from the parts counter at the MB dealer. The drawing in it clearly showed them in the wrong position, and I put my trust in it.)
Well. I got back home and switched them out, and same thing! A bit more troubleshooting found a bad solder joint in the fuel pump relay. Re-solder, and Voila! She started and actually continued to run! (I guess I made my year projection afterall. There's still a good bit to sort out.
Custom A/C hoses, cruise control, front suspension springs, gages, reassemble interior, paint and install ground effects, .....
I'll drive it for a few weeks before I tape up all the wire bundles. I already taped and untaped them several times, so I'll wait until I'm sure all is well.
There were only a couple minor leaks. Transmission dipstick, at the o-ring. (already fixed), and overflow nipple on the radiator. I already tried to repair that once, and may need to replace the rad.
SO... There is light at the end of the tunnel! Much to do yet, before photos get posted!

[blkchambers]

I actually got it out on the road today! Whoopee!! I only drove it four miles, as I didn't want to press my luck. On the test drive, I experienced the throttle sticking a little, a few times. Not too serious, but it got my attention! I'll re-lube all the joints, and maybe try a slightly stronger return spring. The throttle linkage is custom built from the firewall to the engine, so there may even be an engineering flaw, but I don't really think so. I'll keep you posted. Once I got it home, I found a few loose oilpan bolts, causing a slight drip of oil from the back of the pan. Overall, I am VERY satisfied!
The interior is all back together now, which is a big emotional boost. The project takes on an ominous burden with so many systems in pieces, and stuffed in the trunk, the back seat, boxes, and any corner of the shop you can find. All that is dwindling!
By the time I drove the car and it had time to "settle in", it was really only sitting about 3/4 inch higher than with the diesel, not 2 inches as previously reported. I tried one of the 240D front springs, and to my surprise, it actually sat 1/2 inch higher than the 300CD springs! Maybe the 300 springs were worn and sagging, although I never noticed that with the diesel in there. I'll investigate possibilities on new ones.

[H-townbenzoboy]

Yay! :D

When will pictures be available?

[blkchambers]

Still have lots of polishing and detailing. Maybe another month or so for pix.

[Maxbumpo]

I'm sure that the terrific feeling of accomplishment has you on cloud nine! Can't wait to see some pics. Are you going to 'show' the car?

[VLayton]

Hopefully it'll be entered in a Club 123D show one day. What a contender for "Most Customized" :D

[Benzine]

I have followed with great interest in your heart transplant. I have recently purchased a 1982 123 250 factory stretch limo. It is a great car with perfect paint and interior. I would really love to replace the 6cyl 2.5 carby with an injected V8! I pulled a V8 out of a 420SEL over the last week and was dumbfounded by the amount of wiring! I will post some pics of my new ride as soon as I can.

[blkchambers]

There will be several wires that when you install, you have to "wing it", as it is nearly impossible to access the fusebox, even with the dashboard removed. There is lots of fabrication, and design work. After you read all the info on this site, I'll be glad to help with advise when I can, but be sure there are far better authorities than myself on the electrics and mechanics involved. The 420 will actually fit a bit easier, as the deck height is slightly lower.

I put about thirty miles on the car the other day with no significant problems. A small fuel leak creates a slight odor that I need to trace, and I think there's a vacuum leak as there is still a slight hesitation from 0-about 5 MPH.

[blkchambers]

About 200 miles on the clock now.
Oilpan leak turned out to be simply the washer behind the oil pressure sending unit. Oil was dripping down the side of the engine, and flowing to a low point, at the rear of the pan. A new copper washer seems to have stopped the dreaded driveway stainer!
Gas leak has self corrected. I could never find it, and it is now gone. Perhaps it was just residual gas spilt from all those times starting by pouring gas into the throttle body.
Hesitation is partially resolved. Distributor cap had some corrosion inside, so I cleaned it off, and while it's not completely gone, it seems to hesitate a bit less, and run a bit better. A new one, along with a new set of plug wires is on order.
Also on order is a new pair of front coil spring "cussions" Probably the wrong name, but the rubber pads that fit atop the springs come in four thicknesses, from 8MM to 23MM, designated by one to four tics. I had the thickest, and ordered the thinnest. That should lower the front by 15MM, or about .6 inch. While not as low as I want, it's a step in the right direction, and until I can locate a set of lowering springs, it will have to do. It seems that H&R used to make lowering springs for the 123, but no longer do.
I had changed to a 140MPH speedo from a 280E, but this registered about 15% low. Not sure that is the culprit, but I'll put the original 120MPH unit back in and see if that fixes the problem.
All for now!

[Boneheaddoctor]

That makes for a good read...man I would love to be able to see that in person....like they say, pictures are nice but its nothing like being there. :D

[Maxbumpo]

Bob,

What is the new weight of the car? MB made a plethora of springs for the front end of 123 series, depending on weight changes caused by varies options and engines. Perhaps I can't hunt down a part number for you that will get you in the ball park. Also, prices for new springs is reasonable, and much easier to get than used springs at the U-pull.

[blkchambers]

Thanks, but at the moment the car is on the back burner again. I'm renovating a kitchen, and need to finish it as quickly as possible.
I haven't had the chance to weigh the car, but would have thought that the 240D springs should have lowered it. Maybe I'll check into a pair from a 380SL. Not even sure if the dimensions are the same. If anyone has a spare set laying around, and willing to sell them.... The only problem, I'm reluctant to buy any, not knowing what the result will be, and get stuck with another set that doesn't do the job.

[Maxbumpo]

When you have time, check this link out:

http://mb.braingears.com/123_DISK1/program/Chassis/32-220.pdf

Lists all the combinations of springs and pads for every version of 123 ever made, along with the spring part numbers.

From the 1985 Technical Data Passenger Cars;

123.003 = 1690kg (model 250 special-ambulance or funeral coach)
123.007 = 1740kg (model 280E special-ambulance or funeral coach)
123.026 = 1410kg (model 250)
123.028 = 1570kg (model 250 sedan long)
123.033 = 1475kg (model 280E)
123.053 = 1460kg (model 280CE)
123.086 = 1510kg (model 250T)
123.093 = 1560kg (model 280TE)
123.102 = 1590kg (model 240D special-ambulance or funeral coach)
123.103 = 1705kg (model 240D special-ambulance or funeral coach)
123.105 = 1750kg (model 300D special-ambulance or funeral coach)
123.120 = 1390kg (model 200D)
123.123 = 1395kg (model 240D)
123.125 = 1585kg (model 240D sedan long)
123.130 = 1450kg (model 300D)
123.132 = 1630kg (model 300D sedan long)
123.183 = 1515kg (model 240TD)
123.190 = 1570kg (model 300TD)
123.193 = 1620kg (model 300TD)
123.200 = 1555kg (model 230E special-ambulance or funeral coach)
123.220 = 1350kg (model 200)
123.223 = 1360kg (model 230E)
123.243 = 1380kg (model 230CE)
123.280 = 1470kg (model 200T)
123.283 = 1480kg (model 230TE)

From the list above, find a model that is close to your car's weight, then go to the link and find the part number. A couple years ago, the price of a new spring was about $70, probably up to $100 by now, but worth the cost unless you have the right tools and plenty of time to pull them from a junkyard donor.

[Sysco Kid]

:confused:

[blkchambers]

It'll be a while.

[Boneheaddoctor]

Pics ? Heck I'd love to drive it. :D

I bet its a blast to drive.

[blkchambers]

Sorry for the long delay, the condo renovation took a bit longer than I wanted.
I tried to put a couple pix on here and get the old "picture is too large" routine! Not sure how to deal with that. I did spend yesterday working on it, and after about 3 months on the back burner, it fealt pretty good. Worked out a couple glitches, and the big one remaining is the A/C! That is more than a luxury here in Florida, it is a necessity. It'll need some custom hoses, so I gotta locate a shop that can build some, with the MB fittings on the ends. Still need to lower the front, and got thinner spring pads, but that'll only lower it a half inch, so anyone out there with a lineup on some NOS H&R's or similar, I'd appreciate the tip. They are apparently out of production for the W123.

[H-townbenzoboy]

Sorry for the long delay, the condo renovation took a bit longer than I wanted.
I tried to put a couple pix on here and get the old "picture is too large" routine! Not sure how to deal with that. I did spend yesterday working on it, and after about 3 months on the back burner, it fealt pretty good. Worked out a couple glitches, and the big one remaining is the A/C! That is more than a luxury here in Florida, it is a necessity. It'll need some custom hoses, so I gotta locate a shop that can build some, with the MB fittings on the ends. Still need to lower the front, and got thinner spring pads, but that'll only lower it a half inch, so anyone out there with a lineup on some NOS H&R's or similar, I'd appreciate the tip. They are apparently out of production for the W123.

A good way to get large photos up on this forum is to host them somewhere like photobucket, and use the tags to post them.

[Benzine]

How is the beast? I would be particularly interested in the engine mount modifications (how you made them ect . . .) and what you ended up doing with the tailshaft? Would also love to see some pics?

[blkchambers]

I know it's alot of reading, but most items in the conversion were described.

motor mounts were addressed 4/12-21/05

tailshaft addressed 5/8/05

[shnoz]

Hey guys,

has anybody here put a merc v8 into a W123? :eek: I have a 1980 280E and am considering a V8 conversion and am interested to know.

- what merc v8's will fit my car easily? (and transmission)
- did they require much work for engineering?

any info would be helpful

thanks,
nathan

[blkchambers]

No V8 will go in without a fight.
Lots of engineering, but the previous (many) posts will save you lots of experimenting.
Good luck.
Bob

[blkchambers]

I still haven't done anything on the car in months, but at least here's some pix.
Thanks to "Karugs" on Benzworld for helping out with the posting!

http://www.benzworld.org/forums/w123-e-ce-d-cd-td/1284545-blkchambers-280ce-5-0-a.html

Bob

[VLayton]

Bob, if you'd like to send me the pics via e-mail ( club123d@hotmail.com ) I'd be glad to resize them all and send them back to fit here and in the W123 gallery. :)

[blkchambers]

Thanks Vince.
Bob

[VLayton]

Yeah buddy! :cool:

[VLayton]

What a great thread almost two years in the making...

A concept - an adventure - a result... :)

[cervan]

oh my lord! that thing was really shoehorned in there! how many ponys does that have?

[blkchambers]

Not as much as one would hope.
Stock spec is 184HP, 247 lb.ft torque

[Sysco Kid]

this is one of the theads I always like catching up on :)

Michael

[blkchambers]

Car is finally in the A/C shop for some custom hoses. Hardly drove it at all last summer due to the miserable Florida summer heat. Should be back soon, but it's at the same shop that took 10 weeks with the exhaust. Hope this job goes faster.
Still need to address the front spring issue.

[POS]

How can stock only be 184hp? My 280E Euro comes with 185hp from the factory and I've often thought of putting a 5.0 in there, but not if that's the result!

Shouldn't a 5.0 have more hp than that?

[mtupower]

USA m117 5 liter V8's are rated at 184HP IIRC. Euro's are rated at 240 HP. While I like the idea and approve of the project, it does defeat one of the primary goals to put a heavier V8 with less HP than the euro straight 6 into the car.

[Darth V8r]

Keep in mind that the V8 has potential for much more power if one wanted to get serious about tuning it. Additionally, the torque curve for the V8 likely makes a huge difference compared to the six cylinder, even the Euro version.

[blkchambers]

Still looking for a rear airdam. I have the other three, but hesitate to put on only three. Recently there was someone talking about reproducing sets of AMG ground effects. Mine are Zender, but close enough.

[POS]

Still looking for a rear airdam. I have the other three, but hesitate to put on only three. Recently there was someone talking about reproducing sets of AMG ground effects. Mine are Zender, but close enough.

RichmondMercedes.com (Barry Taylor) has a full AMG w123 body kit. It's gonna cost you though.

[blkchambers]

I got tired of hunting for the perfect set of seemingly non-existant lowering springs. I finally, after locating a replacement set if needed, decided to cut off 2 coils from the stock springs. It seems I was overly concerned with the bottom of the spring not seating correctly in its perch, but there is enough compression where it is simply not a factor (so far). I have a hundred or so miles on the car with its new height, and there seem to be no ill effects. Now I need to lower the rear about an inch to even up the car's stance.
So bottom line is all the major systems are now complete, and the project is done, Although it has been a long one, it has been a great learning experience, and a rewarding one.

[JoshuaJeeper]

How far did the car drop with 2 coils gone?

[blkchambers]

About 2.5 " for two coils.I now have several hundred (mostly highway) miles on the car with the cut springs, with a couple rapid evasive maneuvers, with no problems.

[blkchambers]

Upon closer inspection, the 2 coils lowered the car more like 2.75-3"
I got another set of springs from a wrecking yard, and cut 1.25 coils , and brought it back up about 3/4" (remember the bottom coil is nearly flat) Looks better.

[blkchambers]

Running and driving for over 19 months now and NO problems!!

;) eeeha!!

[Maxbumpo]

Have you shown the car off at a MBCA event yet? I'll bet it would be among the most unusual MBs at any event.

[blkchambers]

No, not yet. My work schedule has always conflicted with those events, but I'm gonna try to make it to the Octoberfest in Tampa later in the month.
All German car clubs were invited, so should be fun.
Bob

[blkchambers]

Brought it to the "Gulf Coast Coupes" group meet last weekend in Sarasota.
It is mainly an SEC group, but it did turn a few heads, and gather a good bit of interest.

[BENZITCH]

Barry Taylor?
Where have I heard that name before?
Bruce

[blkchambers]

I took the valve covers, air cleaner, and PS pump cover to be powder coated today. I'll try to get a pic when they're back in.

[blkchambers]

Here's a couple pix of the M117 engine stuffed in the W123.
Running great for over two years. One minor fright. Started running a bit rough a while ago, and I suspected a jumped timing chain. Turned out to be simply a clogged fuel filter. I guess after 20+ years of diesel yuk, and about 3,000 miles later, the filter had enough.

[blkchambers]

Can never seem to get my pix in there? Too big I guess.