424bhp 6.0-litre V12 M120-engined Mercedes-Benz 190E W201

They said it couldn’t be done, but that was just the incentive Johan Muter needed to create this M120 V12-powered 190 saloon.

WORDS & IMAGES ROBB PRITCHARD

Nothing prepares you for the wow-factor of what awaits when Johan pops the hood 190 V12!

Ultimate sleeper 

Can you squeeze Mercedes’ six-litre M120 V12 into a 190 saloon? Johan Muter proves you can!

From a distance, Johan Muter’s Mercedes looks like a well-appointed 190. Apart from the slightly oversized wheels, there’s nothing too much out of the ordinary. Look a little closer though and stainless steel air intakes cut straight through the front lights, hinting that something strange is going on under the bonnet. The engine note, too – a much deeper and more feral growl than that usually heard from a humble 190 W201.

However, nothing prepares you for the wowfactor of what awaits when Johan pops the hood. Somehow, he has managed to shoehorn a massive, six-litre M120 V12 from a 600SEL inside the engine bay. It’s like a supermodel in a onesie and it’s a feat of engineering that from first impressions defies explanation… which is why we went to JMSpeed Shop in the Netherlands to sit down with the designer and engineer himself, and talk through the complexities and solutions he came up with for this unique Mercedes-Benz.

‘How’ is obviously the first question, but we also want to know why. Johan has done a few engine conversions over the years and has experience with sleeper builds, such as fitting a 1972 VW Bug with a 350bhp Subaru STI engine. The inspiration for this 190 build came when he read a few online conversations stating that installing the M120 V12 in a W201 wasn’t possible. “I am the wrong person to hear that something is not possible, and I was interested in the satisfaction of building a car that hadn’t been done before – one that would stand out from the crowd. Not for the purpose of growing my ego, just because of the challenge.” First off, this beast is a fusion of two cars. The shell, and not too much else at all, is a 1984 W201 190 – not even an ‘E’ as this 2.0 had a carburettor. The engine and most of the running gear comes from a 1993 140-series 600SEL with 103,000 miles on the clock, which he bought in the UK.

With the front end of the 190 shell stripped and the old wiring loom removed, it was time to see if the huge V12 would fit. Johan’s careful measurements suggested that it would, but with no one else having attempted such a transplant before there was no guide on the internet to follow, so it was literally just a process of trying and seeing what metal in the engine bay needed cutting away. Surprisingly, and not with just a little relief, the M120 V12 went in, although it was obviously tight enough in some places to require some fabrication. Between the top of the intake manifold and the inside of the bonnet there was about a centimetre of space, but that was all he needed. With the gearbox added to work out how much modification the bulkhead and transmission tunnel needed, Johan fabricated a custom subframe and engine mounts.

The main issue here was how to relocate the steering box so the arm would reach around the much wider sump. He used one from a W210 E-Class which is much smaller than either the 190’s or the 600SEL’s, as well as the rack and pinion housing. Mounted a few centimetres lower with connecting rods from a Hyundai, which were shorter by the right length, and a frame to stop the linkage from connecting with the suspension arm, everything worked fine. The transmission tunnel had to be raised about 30mm and also widened a little to fit the 600SEL’s gearbox, which is bigger and is also positioned 150mm further back.

The 600SEL’s huge rear diff was fitted to the 190’s rear subframe with custom arms from McGill Motorsport in the UK. All the bushes were changed to urethane 80 Shore to give the car a much stiffer ride than standard. The brakes are an eclectic mix of Mercedes parts: 290mm Brembo two-pot calipers from a W210 E320 on the rear, and 300mm four-pot calipers from a 190 Evo on the front with 190 Evo discs. The suspension is BC E36 coil-overs with the top mounts repositioned higher to allow enough space with the bigger wheels to adjust the ride height. The wheels are Segins from a W220 S-Class – 8J front and 9J rear.

The radiator and oil cooler were fitted on custom supports, the space for which necessitated some modification to the backs of the lights and the later ‘update’ style front bumper needed minimal work to fit.

Johan reels off the modifications as though making this special car was like putting together some Lego Technic, but when he gets to the exhaust manifolds it seems that these were the most challenging aspect. After much deliberation, he decided that a 6-to-1 system wasn’t going to be possible in the severely restricted space, so he made a 4-to-1, but where the two flows into the one the steering rack is in the way. The end result is that it’s not too symmetrical and is possibly the only part on the car where Johan had to surrender to compromise, as one bank is routed to a different side of the steering pin than the other. The mufflers, meanwhile, are from MagnaFlow.

Johan reels off the modifications as though making this special car was like putting together some Lego Technic

Up until 1995, the V12 S-Class came with a four-speed automatic gearbox as standard, and as a 1993 model this is what Johan’s car had. In September 1995, the (newly badged) S600 received a 722.621 electronically controlled five-speed unit and Johan found one with just 40,000 miles on it, albeit with a few little gasket leaks to fix. For people who like performance cars, automatic gearboxes aren’t so interesting, so Johan installed a bolt-on controller made by a company called OfGear that allows manual changes. These are operated by paddleshifters from a W204 C-Class on the steering wheel. The interior wasn’t skimped on either and the leather seats and trim come from a 190E 2.3-16, no less. The exterior colour is Mercedes 199 blue/black while the lower panels and bumpers are 7700 Alto Grey.

With the engine out for the last time, bespoke wiring looms from a VEMS V3.8 ECU were attached to a few hard-to-reach sensors such as the one for the crank. A shorter propshaft, a fire jacket to protect the steering knuckle bearings from heat radiating from the engine, and fluids in the oil cooler were the final touches. With heart in mouth, Johan fired up the V12 for the first time. His blood pressure might have been a touch high, however the baby saloon’s gauges read normally.

Before he could take it on the road for a proper test drive, first he had to get the changes registered with the RDW, the Dutch equivalent of the UK’s DVLA. The main issue was that the maximum weight for the front axle of a 190 is supposed to be 735kg, but with the huge V12 it was now up significantly to 810kg. After a bit of head scratching and internet searching, Johan discovered that the 2.3-16 has an 835kg limit, so with a little legal wrangling it was still possible to get his 190 registered. Now he just needed to find a tester who understood how well the modifications had been done rather than someone simply interested in the strict interpretations of the paperwork.

There’s not much point in increasing the power if the handling is rubbish

A suitably impressed inspector passed the car and, as the shell was over 30 years old, it got old-timer status which meant less pricey road tax and insurance. With the new numberplate, Johan was able to take his fledgling creation into the wilds of the German autobahn network just over the border. The 300-mile run-in with nothing overheating, leaking, smoking or failing was a good systems check and so then it was time to see what the car could do with a liberal application of the loud pedal.

“A lot of people want to know how fast this car is. Personally, it is less important for me as this is a statement build. This engine swap was always seen as impossible and I wanted to show what I could do in my garage. I think I have proven the point as the car is really good.” With such a large block up front you might expect that the weight distribution is a bit out of kilter. Not so. “It’s nice to have a powerful engine in a car but there’s not much point in increasing the power if the handling is rubbish,” Johan shrugs. While the V12 is big, it’s also aluminium, whereas the W201 block is cast iron, so it’s not actually that much heavier. The 600 gearbox is longer and also repositioned further back to create more space for the radiator at the front of the engine, which also helps with that balance. The S-Class differential is also about two times the size of the 190’s. The battery, meanwhile, has also been relocated in the boot, contributing to weight distribution of 56/44 per cent (810kg front/630kg rear), which is just 1 per cent off the 2.5-16’s 55/45 split. “It can be driven hard like a race car,” Johan smiles. “And it handles so well in the corners that it’s a real joy to drive, which is what I always wanted.”

Performance wise the car also doesn’t disappoint. At 1,440kg, but with 424bhp and a very nice 585Nm (431lb ft) of torque, this 190 moves as sharply as you would expect. Johan has measured 0-62mph at 4.84 seconds. He’s also hit 155mph and believes 190mph is within reach, but he hasn’t tried to do that just yet…

Well placed inlets direct air to the intake filters. Johan is very happy with how his V12 handles.

Lots of mods needed to make the M120 V12 fit.  

Sleepers, or Q-cars, are Johan's speciality, it seems. Display from gearbox expert Of Gear in Denmark