Engine replacement for my W124

[anthonyw124]

Hey, I'm turning 16 in November, and my dad is giving me our old(ish) 1994 W124 420E, and the first thing I want to do is an engine swap, we've owned this car since 1995, so the engine isn't that powerful anymore, it has a decent amount of KMs on it, around 160000 km, and I obviously can't buy the original 500E hammer but I would die to get one, so I decided to make my own 500E hammer. I want to go with a 2006-2008 550 Mercedes engine as they're really available in my country (M273 or the M278 which is more expensive) and modify it, but here are my questions:

-Do you think these engines can be easily modified?
-Are there lots of parts for these engines?
-Will the W124's engine bay be able to hold lots of modifications?

Hopefully I can get some help with this, thanks!

EDIT: I think I might go with something older like a M119 from an 500S

Edited by anthonyw124 on Monday 9th October 15:24

[northwest monkey]

Have a look on the "Barge Bargains" thread - they love an old Mercedes on there & should be able to give you loads of advice.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Be prepared for the naysayers telling you to get something small etc. Ignore them. My best mate's 1st car was an XJ12 at the age of 17 - it was ace. Broke down a lot, but still ace.

[J4CKO]

That is a big job, I have the M273 in my CLS.

I wouldnt worry that much about ultimate power just yet, 388 bhp might be a little "frisky" for a new driver, perhaps get the car immaculate and learn all the skills ?

[normalbloke]

Anything is possible, sort of. But get a few hypothetical insurance quotes for a laugh..

[Rat_Fink_67]

These guys do this kind of thing all the time...

https://www.mechatronik.de/en/engineering/

I'm not sure how forthcoming they'd e with help and advice but it's got to be worth an email. They may even be able to offer the necessary parts for the conversion such as engine mounts, crossmember, modified sump etc.

[texaxile]

I sold an Escort to a 17 year old the other year. I asked him what his plans were and he told me he was going to put an ST Engine into it. Apart from the horrific logistical problems of putting a different engine from a modern car made into a car that was 18 years old, I did mention the insurance issue.

I'm not even sure you'll get cover tbh, plus all the engineers reports will have to be fairly comprehensive for any of even the most "liberal" of underwriters to consider it.

[northwest monkey]

Don't think the OP is in the UK so insurance is likely to be different.

[red_slr]

I suspect your main issue is going to be electronics. Anything of that age is going to be littered with sensors / ecus etc. Might be worth researching first. Something like an LS swap might be worth looking into or 2JZ?

[J4CKO]

The 420 had 275 bhp, so should be fairly rapid, unless the engine is really badly worn it should still perform pretty well in a W124.

I would suggest spending some time on the existing engine and ensure it is running properly, a compression test and if all is well a full service, plus plug leads, spark plugs, distributor cap, fuel filter etc, then maybe get it set up on a rolling road.

The M273 would be a huge job, you would need the matching gearbox, not sure how it all works with the rest of cars systems, probably more productive to run it on standalone management, and then it would give you another 100 and a bit bhp.

Have you actually driven the car, interested as to how you have decided it isnt fast enough ?

[sim16v]

The W124 420e has a small version of the M119, as found in the W124 500E

Forget about putting in a late 2008 or whatever engine, get a M119 from a SL and use a crank from a W126 560 M117.

It'll give a big M119 with 360 plus bhp and a load of torque.

Everything is a bolt in swap, and you won't need to worry about attempting to get a modern engine running.

[ambuletz]

sounds like a 16yr old with big dreams and no idea. I was similar back then, i told my dad I wanted a skyline..then a supra..then a 200sx...then a 106 gti...ended up getting a fiesta 1.3.

im guessing OP isn't from UK. ireland? somewhere else? as others hasve said the w124 wouldn't have lost much in hp. you're better off prob modifying that instead of doing a labourious engine swap. or just not bothering.

however if you really are willing then I wish you all the best and i think it's a great idea. it's something that really should be a lifetime consideration not something a n00b driver wants as a 1 year project.

[anthonyw124]

sim16v said:

The W124 420e has a small version of the M119, as found in the W124 500E

Forget about putting in a late 2008 or whatever engine, get a M119 from a SL and use a crank from a W126 560 M117.

It'll give a big M119 with 360 plus bhp and a load of torque.

Everything is a bolt in swap, and you won't need to worry about attempting to get a modern engine running.

Yeah, that's what I was thinking of at first, I've seen a ton of m119 500 engines from wrecked W140s, but most of the ones at my local mechanics and part dealers are rusty and have lost lots of horsepower, but if I can get my hands on a clean one I'm definitely buying it.

[CarsOrBikes]

I have an SL500 (w230) engine that was removed in 2007 (1yr old) with 6k on it, after it took a gulp of flood water. Comes with plenum and harness, loose built at the moment due to having it checked, needed two rods if I recall, so will only need mounts, starter, a/c comp, alt. Even has all the coils and drive belt.

Edited by CarsOrBikes on Monday 9th October 15:19

[anthonyw124]

red_slr said:

I suspect your main issue is going to be electronics. Anything of that age is going to be littered with sensors / ecus etc. Might be worth researching first. Something like an LS swap might be worth looking into or 2JZ?

Yeah, my friend told me the same thing, he had this issue. That's why I first thought I would buy a 1990s 500 M119 engine. Honestly Merc and BMW engines are the easiest to find in my country, they're extremely cheap to maintain and have cheap parts, LS engines are hard to find here and especially one with a clean record, and 2JZ are extremely rare because no one used to buy Toyotas in the 90s in Lebanon.

Edited by anthonyw124 on Monday 9th October 16:08

[anthonyw124]

northwest monkey said:

Have a look on the "Barge Bargains" thread - they love an old Mercedes on there & should be able to give you loads of advice.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Be prepared for the naysayers telling you to get something small etc. Ignore them. My best mate's 1st car was an XJ12 at the age of 17 - it was ace. Broke down a lot, but still ace.

I looked at the thread and these guys look very helpful thanks alot for the help!
And yeah I've had some friends telling me I was an idiot to start with that, but honestly I loved the 500E hammer since I was a little kid, so technically I've already got my dream car, my father loved this car that's why we kept it, we've owned 9 cars since we replaced it and it still has its specific place in our garage. So that's really why I'm so attached to it and don't want to get something else and on top of that I've been driving it since I was 13 and know it pretty well.

[anthonyw124]

J4CKO said:

The 420 had 275 bhp, so should be fairly rapid, unless the engine is really badly worn it should still perform pretty well in a W124.

I would suggest spending some time on the existing engine and ensure it is running properly, a compression test and if all is well a full service, plus plug leads, spark plugs, distributor cap, fuel filter etc, then maybe get it set up on a rolling road.

The M273 would be a huge job, you would need the matching gearbox, not sure how it all works with the rest of cars systems, probably more productive to run it on standalone management, and then it would give you another 100 and a bit bhp.

Have you actually driven the car, interested as to how you have decided it isnt fast enough ?

The car has been regularly maintained since 1995 sometimes at the dealer for bigger checks but mostly at my dad's trusted mechanic for regular small checks (I have no idea if the previous owner did it as well tho), the only problem is that I live in a mountainous area, the engine used to go from high altitudes (1500m) to lower altitudes (300m) and the opposite every day for around 2 years which could of most probably have an effect on the engine because of pressure variations and the fact that the car used to go uphill for around 30km daily, so yeah it's a pretty tired engine. I've driven the car on private property since I was 13 and this summer I've driven it a lot in my city as well as tried speeding up with it on long stretches, I have a good time of experience with the car, the car has a hard time responding on first and second gear (0-40kmh) but is totally fine on the remaining gears.

Edited by anthonyw124 on Monday 9th October 16:13

Edited by anthonyw124 on Monday 9th October 16:14

[J4CKO]

anthonyw124 said:

J4CKO said:

The 420 had 275 bhp, so should be fairly rapid, unless the engine is really badly worn it should still perform pretty well in a W124.

I would suggest spending some time on the existing engine and ensure it is running properly, a compression test and if all is well a full service, plus plug leads, spark plugs, distributor cap, fuel filter etc, then maybe get it set up on a rolling road.

The M273 would be a huge job, you would need the matching gearbox, not sure how it all works with the rest of cars systems, probably more productive to run it on standalone management, and then it would give you another 100 and a bit bhp.

Have you actually driven the car, interested as to how you have decided it isnt fast enough ?

The car has been regularly maintained since 1995 sometimes at the dealer for bigger checks but mostly at my dad's trusted mechanic for regular small checks (I have no idea if the previous owner did it as well tho), the only problem is that I live in a mountainous area, the engine used to go from high altitudes (1500m) to lower altitudes (300m) and the opposite every day for around 2 years which could of most probably have an effect on the engine because of pressure variations and the fact that the car used to go uphill for around 30km daily, so yeah it's a pretty tired engine. I've driven the car on private property since I was 13 and this summer I've driven it a lot in my city as well as tried speeding up with it on long stretches, I have a good time of experience with the car.

Its a Merc V8, it will cope with altitude, gradients and pressure changes, is it burning oil ?

I would check the compression and rebuilding the original motor would be a fantastic learning opportunity and not actually that hard if you look into it, take advice and take your time.

I would have to be utterly knackered to be down on power to the point it feels slow, a 420 isnt that far behind a E500 power wise.

Is it knocking, burning oil or down on oil pressure ?

[anthonyw124]

J4CKO said:

Its a Merc V8, it will cope with altitude, gradients and pressure changes, is it burning oil ?

I would check the compression and rebuilding the original motor would be a fantastic learning opportunity and not actually that hard if you look into it, take advice and take your time.

I would have to be utterly knackered to be down on power to the point it feels slow, a 420 isnt that far behind a E500 power wise.

Is it knocking, burning oil or down on oil pressure ?

The transmission has hard time responding on first and and at the beginning of second gear (0-40kmh), on the remaining gears the car has no problem at all, that's the only main issue it has. Yes as you said, I'll take my time once I have the car on a daily basis.

[andy43]

If you think you have the capabilities, do it!
I don't, but I'd love to have the money to pay somebody to stick a supercharged 5.5 engine into a 124 estate.
You're starting with a V8 car anyway, rack, pulleys, mounts etc will all be in the right place for a straight capacity increase to 500e power or even to 6.0 AMG spec as in the SL60 - would be miles easier than getting a more modern engine and electronics to work.
Possibly cheaper in the long run, unless you go to AMG for a new 6 litre crate engine...

[anthonyw124]

Hello! I was recently given our 1994 w124 420E, and I was just wondering if an 1994 M119 5.0 engine from a W140 500S would be compatible with my car, I've got an amazing deal for the engine and it's very clean with 215k kms on it removed from a rear damaged W140 500S from Germany. I thought this would be possible since I share the exact same engine with the W140 420S, but the only thing that I'm afraid about is the ECU (which I don't think is present on my car) and all the electrical stuff.