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Projektname E9: die neue Klasse von BMW anno 1974 – aber ein paar Extra-Meter, Kubikzentimeter und auch PS dürfen es im Triebwerk schon sein!

Who doesn’t like to remember the BMW E9, which was produced between December 1968 and December 1975 and found its way into many children’s rooms at least as a model car and wishful thinking for the future? Today, the elegant coupé, produced by Karmann in the Rheine plant, is a favorite classic car for many. You can cherish it, take care of it, cherish it – or go on a trip with it. The latter applies to a magnificent specimen produced in 1974, which has been sustainably refreshed in our engine. It takes part in vintage road trips and rallies, tours through neighboring European countries. With a fuel consumption that does not correspond at all to the large-volume six-cylinder in-line engine. Possible motto: cleanly adjusted, the 3.0 CSi – our first project under the brand of the national colors blue and white, which in 1917 were incorporated into the trademark of the Bavarian Motor Works, BMW for short.


The BMW 3.0 CSi caused a sensation in the first half of the 1970s. In addition to 30,546 production cars from the E9 model series, it was above all the sports and racing versions that shaped the image of the Munich automobile brand. Burkhard Bovensiepen was one of those players who decisively influenced the era of the six-cylinder coupe. The busy wine lover from Buchloe in the Allgäu was a tuner and racing team owner in one person, the Alpina brand created by Bovensiepen is still a global concept of quality today. The previous US owner of a model delivered in 1974, which passed to the current owner’s inventory two years ago, knew this too. He had already made provisions and found a suitable pool of spare parts long before he bought his favorite vintage car. In two garages, a private collector had brought together pretty much everything that could be useful in an E9, for example a six-cylinder in-line engine from the first 6 series (E24). The 3.5-liter intake manifold injector from the 635 CSi was also used in the 3.0 CSi at an earlier development stage with 218 hp and was therefore legitimate to provide acceleration in the older E9 type as well.


However, anyone who now believes that the increase in cubic capacity and horsepower yield will lead to an escalation in oil and petrol consumption is wrong. The piece of automotive history restored in the United States uses less than eleven liters of fuel. In order to achieve this value, the ignition cables, the ignition coil and the distributor cap have been replaced in addition to a clean basic setting. In addition, the air conditioning had to be renewed in order to keep the energy balance in balance.

The economical nature of the E9 proves its worth in classic car rallies and private road trips, both of which were carried out at short intervals on the British Isles. Because some stages there are long – be it the way between two special stages or simply the distance to the next fuel station in lonely but all the more beautiful areas. After the test in a Scottish rally, it went back to North Rhine-Westphalia on its own for a short moment, before the British Isles called for the second time just a short time later – travel fever on wheels, which kept four specialists at DAS TRIEBWERK particularly busy. Swen Hensel, Tom, Jan, Daniel did a great job as a project team.


Despite the extremely short preparation time before the first test, the BMW 3.0 CSi got through without any problems, apart from a stubborn heater fan at times. Extensive revision measures may have contributed to this: the removal and revision of the rear axle and cardan shaft, the replacement of parts that are subject to wear such as the Hardy disc, also known as a flexible disc, the clutch, hoses and tires were just as much part of the scope of the measures as the powder coating of the Alpina rims with their characteristic straight spokes. Welding work on the spare wheel well after rusting through was discovered and the renewal of the exterior paintwork below the decorative strips also belonged to the scope of work. The result: a piece of contemporary automotive history that was delivered almost five decades ago, which, with optimizations and fine adjustments in the decisive areas, has become something more than would be expected from a typical classic car. For us at DAS TRIEBWERK, this is the motivation par excellence: A few extra meters are fine, but not a few extra drops of petrol or oil: modern and (energy) efficient also works in the old, classic guise.


Responsible for the content: netzwerkeins GmbH, Carsten Krome

At a glance: BMW 3.0 CSi (E9, model year 1974) – the most important project details


Vehicle base: purchased in 2020 ready to drive, already pre-restored in the United States according to the criteria applicable there; M30 engine from the 635 CSi (E24 type) installed and verified based on the documented development history; 218 hp from 3,500 cc displacement


Measures DTW Germany | Das Triebwerk (body, exterior): welding work on the spare wheel well after rusting through; Renewal of the exterior paintwork below the decorative strips


Measures DTW Germany | Das Triebwerk (technology): Removal and revision of the rear axle and cardan shaft; wear-relevant parts such as Hardy disc (joint disc), also Giubo clutch, clutch, hoses and tires renewed; new powder coating of the Alpina rims


Measures DTW Germany | Das Triebwerk (electrical system): ignition cable, ignition coil and distributor cap renewed


Measures DTW Germany | Das Triebwerk (interior): renewal of the air conditioning system


Project team (DTW Germany | Das Triebwerk): Swen Hensel, Tom, Jan, Daniel