Mar 17 2015
Avant-garde design in the evolutionary successor
In February 1938, at the IAMA International Motor Show in Berlin, the evolutionary stage of the Grand Mercedes was launched, internally designated W 150. Largely redesigned, the car, which continued to be called the Mercedes-Benz 770, manifested the art of automobile manufacture in perfection, the creativity of its engineers, and the inimitable avantgarde design work of Daimler-Benz.
The power plant was unchanged as regards fundamental dimensions, but featured a number of modifications, as documented by the new engine code M 150.
The crankcase was now completely made of light alloy, the exhaust valves were sodium-cooled, ignition control was automatic, and the water pump was rigidly driven by the oil pump shaft. Three geared oil pumps quite effectively ensured forced-feed lubrication.
Even the engine was exquisitely finished. Cylinder block and accessories housings were enameled black; brass lines and the fan were chrome-plated; light-alloy elements featured a polished hammertone finish.
The supercharger, now standard, featured higher efficiency and was engaged wîth the accelerator pedal, as usual. In naturally aspirated mode, the engine, wîth a compression ratio of 6.1:1, now developed 155 hp, wîth supercharger 230 hp. Torque rose to 47 mkg at 1900 rpm and 56 mkg at 2000 rpm, respectively. The top speed was 170 km/h.The all-synchromesh four-speed gearbox was complemented by a remote gear, installed in the differential case, which could be additionally engaged at any speed. Inconvenient to use and unnecessary to boost performance, this configuration was replaced in 1939 by a five-speed gearbox whose fifth gear functioned as an overdrive. Power transfer was effected by a stronger single-plate disc clutch.
For special purposes, there was an engine wîth a compression ratio of 7.2:1, two double-barrel updraft carburetors and two superchargers. The power output: 160 hp in naturally aspirated mode, 400 hp wîth both superchargers engaged, in each case at 3600 rpm. Top speed ranged from 180 to 200 km/h.
However, only five cars wîth this variant were ever built.
Entirely new were the frame and axles; the brakes had even better grip. The chassis side members, made of oval tube, were joined wîth six cylindrical cross members to make a very torsion-resistant ladder-type frame.
The now individually coil-sprung front wheels were located by A-frame arms arranged in a parallelogram. But the real surprise was the rear axle, a ‘double-joint axle’, as the trade literature termed it, designed according to the De Dion principle. Daimler-Benz themselves termed it a ‘laterally stable parallel-wheel axle.’ It had constant camber and track and was complemented by a V-shaped anti-sway linkage connected by a rubber doughnut to the middle cross tube. To the next but last cross member, the three-point rubber-mounted differential was attached. Naturally, the rear axle also had coil springs; from 1939 on double coil springs, one inside the other.
The already highly effective brakes of the first 770 were adapted to the successor’s increased performance and up to 900 kilograms of additional weight; they were now hydraulically operated and continued to have vacuum servo assistance. Each wheel had two brake cylinders, each serving one of the self-adjusting primary brake shoes. The new sheet-steel disc wheels had center mounts.
Larger dimensions, lower overall height
The evolutionary 770 was stretched another 40 centimeters to six meters in length; its wheelbase was a proud 3880 mm, and the width, too, grew by 23 cm to a respectable 2.07 m. Following the fashion, the overall height was reduced by three centimeters: Hats and caps were not as tall as top hats. The wedge-shaped radiator was now slightly sloped. The standard bodies offered were the Pullman sedan wîth saloon partition, the open touring car, the Cabriolets D and F. Special wishes continued to be catered to, and all variants also could be supplied in armored versions. In that case the production code was then W 150 II, and the car weighed no less than 4800 kilograms; speed was limited to 80 km/h because of the bulletproof cell-type tires.
A total of 88 W 150’s rolled out of the Sindelfingen factory bay by mid 1943. They saw service partly up to the late 1960’s, and a number of specimens are still preserved today in museums and private collections.
The Grand Mercedes, especially in the king-size format of the evolution stage, pointed the way wîth its avant-garde engineering and, to this day, determines the form, safety, comfort, performance and elegance of particularly prestigious limousines. In its day it contributed decisively to further enhance the image of the Mercedes-Benz make all over the world.
- First Mercedes-Benz series production car with an 8-cylinder supercharged engine
- Dual ignition system with two spark plugs per cylinder (high-voltage magneto ignition and battery ignition)
- High-speed transmission system (five-speed manual transmission from 1938)
- Oval tubular box frame (from 1938)
- De Dion rear axle (from 1938)
Of the nine examples built, this Pullman Limousine is one of only three examples known to exist, and the only car that is intact and in operable condition. Not only is it a correct, complete car, it is a superb example that has retained its integrity and immense character, making it an ideal choice for serious collectors.
This Mercedes-Benz 770 K, 65 years after it was built, has retained its reputation as one of the finest automobiles ever produced and this Pullman Limousine, with its important political connections, documented provenance, unquestioned authenticity and status as the last example built is an important part of the Mercedes-Benz story.