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American V8 Engine Swap for W126

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BaldBollocks's picture
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Hi Gang

Does anyone know of a Modern Fuel Injected Chevy / Ford / Chrysler V8 engine swap into the W125 chassis ?

I have a 1982 380 SEL with a worn out engine. The original engine is a little wimpy.

If I do the swap I may market a kit.

Let me know what you think.

Die hards remember it would save a lot going to the wrecking yards

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familydieseldr's picture
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Re: American V8 Engine Swap for W126

I put a Chevy 350 w/ TH400 in my 1970 280SEL.

Quite a job.

http://i180.photobucket.com/albums/x257/fish1_07/1hhcar.jpg

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1983 300TD = old clacker 370,000-retired parts donor
1985 300SD = Son's Diesel cruiser 332,000
1985 300TD = Dad's Diesel wagon 183,000
1992 Kubota Diesel tractor = mutant lawn mower 390hrs
2000 Ford Powerstroke Diesel = Wife's Toyota crusher 253,000
2004 Chevy Blazer = Daughters gas SUV 80,000
2010 BMW 335d = new clacker toy 56,000
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Re: American V8 Engine Swap for W126

Thanks Buddie for the reply

I see thats quite a front oil sump you have there. What other troubles did you have to overcome with clearance ?

Did you get any previous info from anywhere ?

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Re: American V8 Engine Swap for W126

Hi,

The only place to put the oil pan sump was in front of the frame crossmember.
Started w/ a pan for a race boat, heavily modified http://www.aviaid.com/

The oil filter had to be remote mounted using Aeroquip and TRACO HW.

No room for a mechanical fuel pump, used a HOLLEY electric pump back at the tank.

No room for exhaust headers, I used the old "Rams horn" cast iron exhaust
manifolds, cut off and repositioned/rewelded the flanges to fit.

Fabricated the TH400 trans mount on the stock MB trans mount cross piece.

Converted to a one-piece driveshaft, custom made, chevy yoke on one end, MB on the other.

Installed a 2.82 locking differential gearset from a 300SEL 6.3 inside the stock 280SEL
differential housing (easier than converting the rear to air suspension)

Electrics and AC spliced together no problem.

Special order front springs for "rough duty roads" installed to support the additional
weight.

Radiator from a 300SEL 6.3, biggest CFM electric fan possible was needed.

TIMEVALVE made me a 300SEl 6.3 exhaust and some Chevy fire rings so I could weld it all
up to use the stock hangers.

The best part was that no one could tell from the road that the car was not stock.

The Chevy 350 was built up to about 300-325 HP, cammed for torque.

Accelerating up the freeway on-ramps was fun, I suspect the other cars shrinking in the rearview mirror were wondering what the heck????

Familydieseldr

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1983 300TD = old clacker 370,000-retired parts donor
1985 300SD = Son's Diesel cruiser 332,000
1985 300TD = Dad's Diesel wagon 183,000
1992 Kubota Diesel tractor = mutant lawn mower 390hrs
2000 Ford Powerstroke Diesel = Wife's Toyota crusher 253,000
2004 Chevy Blazer = Daughters gas SUV 80,000
2010 BMW 335d = new clacker toy 56,000
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Re: American V8 Engine Swap for W126

You guys are insane!! Not in a bad way, just insane.

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Gustav's picture
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Re: American V8 Engine Swap for W126

I am in the process of installing a 1990 Corvette TPI engine with a GM 700R4 transmission into my '68 250SE.

The challenges:

1. modified engine crossmember for clearance of oil pan.
2. heavily modified oil pan to clear crossmember and retail oil volume.
3. remove stock steering and replace it with a rack & pinion from '98-03 Chevy Malibu
4. Shorty headers from Sanderson. These fit and provide clearance. Quality is great, but their service SUCKED!!! (They told me they would ship them out within 10 days of my call. It took them a month to ship them)
5. Transmission tunnel had to be modified to make room for the transmission. If I had to do it all over again, the car would have gotten a ZF 6 speed from the Vette. That would have required almost not tunnel mods.
6. I had a custom high efficiency/high capacity aluminum radiator custom built for my allication. In addition, the engine will also have a seperate engine oil cooler. This set up does not require remote locating the oil filter.
7. Stock speedo will not work anymore. Installing custom gauge panel.
8. Will need a custom driveshaft. These are not cheap and don't cheap out. Modifying the stock one is a BAD idea.
9. custom exhaust system. This is not built yet, but should be really easy compared to the rest.

My goal is to have the car operating under its own power in March. The engine will fire up before Christmas.

By the way, what did Aviaid charge for the oil sump?

Engine1.jpg Engine w Accessories.JPG
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Re: American V8 Engine Swap for W126

Gustav,
WOW, that is going to be a wonderful combination!

I think the oil pan cost was about $100 (15 years ago ...), but the time to modify
the sump would have been many more $$$ if I would have had to pay a welder/fab guy
instead doing it myself.

I used Parker Stratoflex 213 hose to connect the oil pump (in the rear of the block on SB chevy of this vintage) to the sump pickup 18" in front of it.

This flexible hose tolerates imersion in high temp oil without deteriotation, and allowed the pan to be made in one piece, no leaky removable panel needed to connect the plumbing for assembly.

Familydieseldr

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1983 300TD = old clacker 370,000-retired parts donor
1985 300SD = Son's Diesel cruiser 332,000
1985 300TD = Dad's Diesel wagon 183,000
1992 Kubota Diesel tractor = mutant lawn mower 390hrs
2000 Ford Powerstroke Diesel = Wife's Toyota crusher 253,000
2004 Chevy Blazer = Daughters gas SUV 80,000
2010 BMW 335d = new clacker toy 56,000
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Re: American V8 Engine Swap for W126

dan holm;121631 wrote:
You guys are insane!! Not in a bad way, just insane.

Dan;

Thank you for the compliament.
My first choice was to stuff a V12 from a W140 between the fenders, but the outragous cost ($17-23000 for the engine/transmission combo) stopped that idea dead in its tracks.
Then a good friend of mine donated this engine to me. So far, the conversion cost has been very tolerable.

The true insanity will come when this thing is on the road. The rear end is a 3.92:1. It is going to be stupid quick with 300hp (double of the stock 2.5 liter 6) and a ton of torque.
The mandatory front brake upgrade will be next after the beast is running.

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Re: American V8 Engine Swap for W126

Mike Ramay from MBCOUPES.COM is doing a 126 coupe with a corvette heart transplant.

I think he is almost finished. He is definately an interesting engine nearing kind of guy.
Bruce

PS And he and Gale are gracious hosts!

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Bruce
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Re: American V8 Engine Swap for W126

now we are talking lets hope he has some pictures for us ?

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Re: American V8 Engine Swap for W126

hey I should have said a 126 chassis

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Re: American V8 Engine Swap for W126

BaldBollocks;

The power train conversion process will still be similar no matter which engine you will be fitting between the fenders of a car that it was not intended for.

The real key is to put a general game plan together and then not be surprized if you have to perform a lot of custom fabrication to make it work in its new home.
In the process, you will get frustrated, purists will complain that you are "*#*#*#*#*#*#*#izing" the original.
At the end of the day, its your project. Enjoy the trip. Its alot of fun and very educational.

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Re: American V8 Engine Swap for W126

Thanks fellers

I'm doing a lot of research into this swap.

Some people would have a real herd time with a FORD engine although the mod V8 overhead cam seems to be OK

Chrysler parts are just too unreliable.

Looks like everything points to the 350 GM engine and tranny.

The rear sump on almost all America V8’s is the biggie here and the GM aft oil filter fouling the steering box

Like I said I do have my own home engineering business and will most likely market a kit when completed.

Looking into modifying the cross member to except a power rack and pinion unit. This will clear all that pitman arm and stuff from the rear of the engine bay.

Of course all parts will have to be reliable and dirt cheap from a wrecking yard or Craig’s list.

Let me know if you have any good ideas ?

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Anonymous's picture
Re: American V8 Engine Swap for W126

ever thought about going import?.. like a nissan u can get a VG twin turbo.. or a ca18det, sr20 or RB(skyline motor) all can put out the same power as a v8 with out to much work... they weight less and itd be alot different.. parts are pretty cheap

and the;re already boosted... if u ever been in a boosted car u know everytime the boost hits u get a big smile:D (the're good on gas when ur out of the boost)

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Re: American V8 Engine Swap for W126

I gave it some though rollingstock but I want to be able to get parts that are in plentiful supply with a huge aftermarket support. i.e. tonnes in the scrap yard cheap.

The 5 & 6 litre GM engines do have gobs of power & torque ideal for the hefty 380 SEL

But I'm still reseaching and measuring ? thanks

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Re: American V8 Engine Swap for W126

It would probably be a lot cheaper and easier to find a 450 or 560 engine. But if you're the adventerous type check this link. Although geared to putting a new engine into a 107 it may give you some idea of the task of putting an american block into a german car. This link will take you to the chev engine section and there is a link to ford as well as using a 560 block.

http://www.carcentric.com/450SLswap.htm

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Re: American V8 Engine Swap for W126

BaldBollocks;122631 wrote:
I gave it some though rollingstock but I want to be able to get parts that are in plentiful supply with a huge aftermarket support. i.e. tonnes in the scrap yard cheap.

The 5 & 6 litre GM engines do have gobs of power & torque ideal for the hefty 380 SEL

But I'm still reseaching and measuring ? thanks

ya when the motor wentout in my 16v the first idea that came in my head was to swap over a gm 350.. but after talking with a friend and thinking real hard about it. it just doesnt seem right for my car.. Im pretty set on swaping a ca18det(jdm nissan motor). at only $900(foreverything) + shipping.. being alot lighter than the 350..comes with 170hp in stock trim.. but its got a cast block... probly can get close to 200-250hp with the stock turbo with little mods.

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Re: American V8 Engine Swap for W126

Gustav

why did you choose the a rack & pinion from '98-03 Chevy Malibu ?

Changing to rack & pinion is the only way to get clearance I can see . I was looking at the 02 Toyota tercel lots of them in the wrecking yards.

your not using the steering columb too are you ?

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Re: American V8 Engine Swap for W126

Sorry for the delayed response - very busy the last few weeks.

The GM Malibu rack was chosen for the following reasons:
it is a "rear-steer" rack. It will fit with only slight modifications to the tie rod ends and it will work with the GM powersteering pump and I was able to get it from a salvage yard for $75. The Malibu is only slightly lighter than the W108 Benz.
The biggest issue is packaging everything. There is very little room under the engine even with a custom built oil pan.
The current location of the rack is not final. It really has to go up about 2.5 inches, but there is only about 1 inch left to go up.
The real way to cure this is to discard the original engine crossmember and custom build one that meet all requirements - but that is just not in the budget at this point (*#*#*#*# accountants ruining all the fun again......:D)

Steering3.JPG Steering4.JPG
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Re: American V8 Engine Swap for W126

You'll be replacing an aluminum engine with an iron engine, thereby increasing front weight.

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Re: American V8 Engine Swap for W126

lkchris;125227 wrote:
You'll be replacing an aluminum engine with an iron engine, thereby increasing front weight.

lkchris;

The SBC I installed in my W108 is actually a few pounds lighter than the 2.5 liter 6 cylinder it replaced.
I can not speak for the engine family that is in the W126 though.

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Re: American V8 Engine Swap for W126

How about a 500 cid Cad? Low cost, light weight, lots of torque and a front sump if donor is a rwd car. I've one of these out to 512 in my 3/4 ton 4x4 Suburban. Lots of power. Aftermarket parts are available.

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Re: American V8 Engine Swap for W126

Anyone finish a swap? I want to discuss this in the forum. Did the center of the engine require cutting the firewall to put in the transmission. Did you consider a dry sump set up. I own a 126, 500 SEC.

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Re: American V8 Engine Swap for W126

I just wanted to bump this thread to hear any progress of any of the swaps. I am looking at a 302/C4 swap in my 73' MBZ 280.
Anybody???

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Re: American V8 Engine Swap for W126

Kinda like putting a Yugo engine in a Mustang...

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Re: American V8 Engine Swap for W126

Woops, I should have asked for "constructive" input... :confused:

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Re: American V8 Engine Swap for W126

I have done about 10 engine swaps for clients over the last 20 years and the easiest by far is a Ford engine into a benz as they usually have front sumps on them which works perfect for the Benz. That way you can leave the steering components as they are. The last one I did was a Ford 460 in a W111. Almost all of the Ford engines have the Oil pump in the front of the engine so it makes perfect sense to do that swap. The beautiful thing about these swaps is the amount of room in the engine bay for the swaps. Almost enough room for a Holly Pro supercharger to fit as well under the hood.

Anrdew

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Feed it kraut not rice.........
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Re: American V8 Engine Swap for W126

i'm doing a swap right now, because of the space problem i'm removeing the steering box and going to a gm rack and pinion. what i was looking for was higher hp, tighter handling and space to have headers all at the same time low cost but high engineering with a professional look. i'm working with chuch brother racing to build a custom crossmember to hold the gm rach in place without a bunch of welding and can be removed with just 4 bolts if you ever wanted to go back to stock, this will be a kit that you can buy and just add rack and pinion to your126 car even if you are not removeing your mercedes engine. today i'm test fitting the protype into my car.and for the record i'm not getting paid a dime out of this project i just saw a problem and saw a way to fix it professionally . in my past i worked as a auto mech. design engineer solving problems . some of you guys love your cars the way they were built and that's great, i love trying to make them better by using newer tech. i have two mb that i love them as they are but i find other ones i just got to find a way to make them work better.since the prototype is here i'll now post pics for you to follow along.:)

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Re: American V8 Engine Swap for W126

What I do is use the Mercedes motor mounts and fabricate a motor mount arm to go from the Ford engine to the Mercedes mount, that way I am not cutting or welding on the subframe. Also it makes for a smoother engine with the Mercedes mounts. As for the steering, remove all of the arms and hang the motor where it should be and then fit the steering back to check for clearances. I have never had to cut any part of the subframes or off the cars to do my retrofits. First hang the engine in the engine bay where you want it with a cherry picker and have the Mercedes mounts installed in the car, and then cut out some cardboard templates to start.

Andrew

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Feed it kraut not rice.........
1994 E36 coupe w/ headers and 5spd 305hp
2002 E55 w/ supercharger and headers 550hp
2003 SL500 w/ supercharger and headers 450hp
1963 300SEb under construction.....

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Re: American V8 Engine Swap for W126

very smart ! and you get avery clean look that has the same mb engineering. with my rack and pinion design i'm not cutting the crossmember. i'm just drilling 4 hole and adding a crossmember that is set up to hold a gm or mb rack. again i'm doing this to install a american made engine.

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Re: American V8 Engine Swap for W126

Hey guys,
Can we get some more pics!!!! I'm right in the middle of my 302/C4 swap in my 73' and would love to see some more photos of projects!!!

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Re: American V8 Engine Swap for W126

Hi Folks... I'm also in a middle of a ford 302 into a W123 280CE. Engine in place.. just need more time to go finish it. Now I'm scared of the electronics.. which wire to use on what on the Ford engine. Has anyone used a totally new off the shelf universal harness into one of these projects or the old wiring would work just as well??

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