This car is best known in enthusiast circles as “The Green Machine.” It’s the only one of its kind ever made, having been built for the former boss of Dresdner Bank with a mighty Mercedes-Benz M100 6.9 V8, a period AMG body kit, Penta alloy wheels, and a 5-speed manual transmission.
The Mercedes M100 6.9 V8 engine was unveiled in 1975 under the hood of the Mercedes-Benz 450SEL 6.9, a high-performance four-door luxury sedan weighing 1,985 kgs (4,376 lbs). The engine was capable of 286 bhp at 4,250 rpm and 403 lb ft of torque at 3,000 rpm, and could push the sedan to a top speed of 225 km/h (140 mph).
Fast Facts – The Mercedes-Benz 450SLC 6.9 “Green Machine”
- This unique 1976 Mercedes-Benz 450SLC was custom-built for a former boss of Dresdner Bank with a 6.9 liter M100 V8 engine from the Mercedes-Benz 450SEL 6.9 sedan. This massive 286 hp V8 gave the lightweight SLC coupe exceptional performance, propelling it to a top speed well over 140 mph.
- Extensive modifications were made beyond just the engine swap, including adding a period AMG body kit, Penta alloy wheels, side vents, a custom roll bar, Schroth harnesses, green corduroy Recaro interior, refrigerated rear compartment, and a 5-speed manual transmission.
- The M100 6.9 V8 was an oversquare iron block design with alloy heads, a single overhead cam per bank, two valves per cylinder, and produced a monstrous 403 lb ft of torque in addition to its 286 bhp output when new. It had a dry sump with a 12 liter oil tank mounted in the right front fender.
- Originally a one-off commissioned build, the “Green Machine” is now part of the Barry Taylor collection and will be auctioned by Bonhams on June 24th with an estimated price of $45,000 – $60,000 USD. It will require mechanical recommissioning before being driven again.
Building The Green Machine
The idea of fitting the Mercedes-Benz M100 6.9 V8 into the Mercedes-Benz SLC coupe was likely deemed too ludicrous for any serious consideration within Mercedes offices in the 1970s. While the new engine could theoretically fit into the engine bay, the power output was such that it would give the SLC monstrous levels of performance – which may be have been considered a little too dangerous in the hands of the general public.
The Mercedes-Benz 450SLC was marketed by the company as a modern day successor to the legendary Mercedes-Benz 300SL Gullwing. Image courtesy of Mercedes-Benz.
Ultimately the car would be built privately, exactly who did the work is seemingly lost to history, but the work they did remains impressive all the same. The Mercedes-Benz 450SLC would be the starting point for the build, a car already powered by a 4.5 liter Mercedes M117 V8 producing 222 bhp and 278 lb ft of torque, considered solid figures for a luxury coupe in the emissions-restriction-heavy era of the 1970s.
The 450SLC had a top speed of 218 km/h (135 mph) which was ample for its intended role as a luxurious GT car, it seems it was insufficient for at least one owner – a former boss of Dresdner Bank based in Frankfurt, Germany.
With what must have been a heavy and very open wallet, he commissioned a rebuild that would see a 1976 Silbergrun Metallic 450 SLC converted into what was almost certainly the fastest non-motorsport SLC of the time.
The original 4.5 liter V8 was removed and replaced with a Mercedes-Benz M100 6.9 V8 which was mated to a 5-speed manual transmission.
Manual transmissions were pretty rare in the Mercedes-Benz R107 and C107 model family, almost all were fitted with automatics, and surviving manual versions are now worth a significant price premium. manual transmission swaps are in demand, and companies like The SL Shop in the UK specialize in selling manual conversion kits.
The Mercedes-Benz M100 6.9 V8
The Mercedes-Benz M100 6.9 V8 had debuted in 1975 fitted to the Mercedes-Benz 450SEL 6.9. Despite the “6.9” in the name, the engine actually has a displacement of 6,834cc (6.8 liters or 417 cubic inches). It was based on the earlier 6.3 liter version of the M100, and both engines had an iron block, alloy heads, a single overhead cam per bank, two valves per cylinder, and either electronic or mechanical fuel injection depending on the specific version.
With a displacement of 6,834cc (6.8 liters or 417 cubic inches) the Mercedes-Benz M100 6.9 V8 is capable of 286 bhp at 4,250 rpm and 403 lb ft of torque at 3,000 rpm.
In standard tune the M100 6.9 V8 was capable of 286 bhp and a tectonic-plate-wrinkling 403 lb ft, a significant increase over the 222 bhp and 278 lb ft in the original 450SLC V8.
The 450SLC was far from a lightweight, in fact the R107 and C107 models have been jokingly referred to as “Panzer Wagons” due to their heft, but even with this accounted for the SLC still tipped the scales at 345 kgs (761 lbs) less than the car that the M100 6.9 had been intended for.
The Green Machine: Specifications
This engine swap wasn’t the only change made to the Green Machine. It was also given a handsome period-correct AMG body kit, color-matched Penta alloys, and side vents cut into the front wings – possibly to help cool the engine bay and the oil storage tank mounted inside the right front fender.
The M100 6.9 had a dry sump design and it required 12 liters of oil, an enormous amount, and so the oil tank in the fender could get quite hot under strenuous driving.
The car is finished in an above mentioned shade of green called Silbergrun Metallic, it has a very 1970s-style green corduroy interior including Recaro sport seats trimmed in correct Mercedes-Benz velour fabric. For the sake of safety it also has a custom fitted and upholstered roll bar and Schroth harnesses, as well as a refrigerated rear compartment, a Blaupunkt “Gooseneck” radio controller, and a wood-rimmed steering wheel.
This car has been modified internally as well, with Recaro sport seats trimmed in correct Mercedes-Benz velour fabric. For the sake of safety it also has a custom fitted and upholstered roll bar and Schroth harnesses, as well as a refrigerated rear compartment, a Blaupunkt “Gooseneck” radio controller, and a wood-rimmed steering wheel.
It rides on four-wheel independent suspension and it has four-wheel disc brakes, all inherited from the 450SLC of course, and it’s fitted with Bosch fuel injection. It’s not known how long the original owner kept the car, what we do know is that it found its way into the Barry Taylor collection where it has been carefully preserved for many years.
The car is now due to roll across the auction block with Bonhams on the 24th of June with a price guide of $45,000 – $60,000 USD and a note that the vehicle will require a mechanical recommissioning before any driving is attempted. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bonhams + Mercedes-Benz
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