The situation for East German industry in the immediate post-war years was both chaotic and catastrophic. All manufacturer's were in ruins and almost all specialist component manufacturers were in the western zone. It would take a concerted, national effort to put together a functional industry. This technical report, written in late 1953, outlined developments and challenges within the industry.
The full publication is extremely technical and of limited interest to a general audience. I have only included the section on the IFA F9 in this post. I will extend the post with details about the BMW/EMW and other vehicles later.
Preface to the 1st edition
The nationally owned motor vehicle industry is facing great challenges: it must keep pace with the rapid upward development of our entire industry in order to cope with the significantly expanded transport and traffic tasks. These tasks, as well as the steady rise in the standard of living of our people, require that the motor vehicle industry broaden its program by developing new types and improving those already in production.
This task may be one of the reasons why the engineers and designers of the automotive industry asked this publishing house to present the most important new developments at home and abroad, technical improvements, and a critical appraisal of our own production in a book. The publisher believes that this book is fulfilling this wish. The main part of its content consists of essays that have appeared in our magazine "Motor Vehicle Technology." To venture into the special importance of fluid mechanics for the development of new types, Professor Jante has also started a work on this area.
May this book be a help to the technicians in the automotive industry, but especially to the designers, in solving the great task that the five-year plan poses to them.
December 1952
Preface to the 2nd edition
The present second edition of the work "German and Foreign Motor Vehicles" was necessary in order to meet the suggestions and wishes of experts.
The revision of the second edition mainly extended to the shortening of the section "Passenger Cars" in order to be able to include important treatises on the theory of motor vehicle technology. In addition, new test results from Soviet motor technology were included in order to make the experiences of the Soviet Union known to German colleagues. A technically better compilation of the various essays will be particularly useful for students, as they will then have the necessary documents for their studies in hand before the comprehensive three-volume work "Motor Vehicle and Motor Science" is published by VEB Verlag Technik.
November 1953
English Translation
When a few years ago a small group of men proclaimed that in the not too distant future the nationally owned vehicle industry would mass-produce passenger vehicles that would be on a par with the best international automotive technology, their optimism was widely ridiculed. The IFA F9 is proof of the great ability of the skilled workers, technicians and engineers in our state-owned organization. The fact of such an achievement only a few years after the end of the war, and despite the bottlenecks caused by the division of Germany, demonstrates good prospects for the fulfillment of the five-year plan here, as in many other areas of our development.
International technical development did not stand still, and the demands placed on a modern, small car in terms of road holding, driving comfort and average distance traveled had become higher. The nationally owned vehicle industry should therefore create a new car that met these requirements.
This task was not easy to solve for various reasons. Above all, the new type had to be superior to the old F8 in the most important properties. IFA has undoubtedly succeeded in doing this with the F9. Yes, a completely new vehicle class has been created, a small car in terms of cubic capacity, weight and fuel consumption - with the performance of a mid-range car! And this explains the fact that in addition to the F9 as a small car, the F8 can still be built, because with the F9 a group of customers have been gained that were previously dependent on mid-range cars.
The fundamentally new design direction of the F9 is particularly evident in the engine. The engine, which is no longer installed transversely but in the longitudinal direction of the vehicle, is of course a three-cylinder two-stroke engine with flat pistons and reverse flushing, proven hundreds of thousands of times in terms of its simplicity, performance and economy. Three cylinders are combined into one block and result in a total displacement of 900 cm3. Each cylinder has a 70 mm bore and 78 mm stroke, with a stroke volume of 300 cm3, which experience has shown is favorable for small, high-speed two-stroke engines. In contrast to its predecessors, the engine of the F9 does not have a separate crankcase, but only a closing pan screwed against the cylinder block/crankcase from below, forming three true crank chambers with the upper part, in which the three conrods are set off 120 degrees from each other (the crankshaft journals are hydraulically compressed from individual parts) and run in roller bearings. The chambers are sealed against each other on the bearings by labyrinth-rings and on the end chambers by rubber sleeve seals. The connecting rods also have roller bearings, while the piston pins lie in the usual way in the light metal piston with an adhesive seat and are secured laterally by snap rings.
The arrangement of the control slots in the cylinders is known from earlier reverse scavenging engines. Skillful, mutual displacement of the scavenging axes of the cylinders results in a short design of the entire engine and the lead out of the inlet ducts to one side of the block and all of the exhaust ducts to the other.
The light metal head carries hemispherical compression chambers, the contents of which are dimensioned in such a way that a compression ratio of 1: 6.25 results, with which the engine runs without ringing thanks to its favorable scavenging conditions with only limited knock-resistant fuel [79 octane fuel]. The fan shaft is placed through the head, which is driven in a triangular drive with the left-hand 190 watt alternator by a V-belt and on which the four-blade fan sits at the rear, which is attached to the radiator behind the engine in order to fit within streamlined engine bay. The fan supplies the cooling air for the thermosiphon cooling, which is sufficient under all operating conditions. Total content of the cooling system is 10 litres.
The ignition is placed on the side of the head at an angle of 18mm as a battery ignition, a worm drive on the front of the engine drives the distributor. The ignition coil is also attached to the front of the engine, while the 0.6 HP starter is arranged on the right side of the engine in the usual way so that its thrust pinion meshes with the flywheel teeth. The entire electrical equipment of the F9 is of course a product of the state-owned industry.
The preparation of the fuel-air mixture for the engine takes place in a horizontal float carburetor, which is fitted with an upstream wet air filter and intake silencer on a distributor mounted on the engine block that has been carefully designed for even mixture distribution and is equipped with an automatically shut-off starter device. It is also a product of the nationally owned industry (BVF) and significantly contributes to the vehicle's favorable fuel consumption values. The fuel is gravity fed from the petrol tank so that all sources of interference associated with fuel pump pressure delivery are avoided.
This engine also uses the tried-and-tested fuel-mixture lubrication, i.e., the engine oil is simply mixed with the fuel at a ratio of 1:25 when refueling - everything then takes place automatically in the engine. The technical and economic advantages of fuel-mixed lubrication are just being demonstrated in the high-performance engine.
A manifold on the engine side leads the exhaust gases to a common pipe, then to the large-dimensioned muffler, which is precisely tuned for dynamic pressure, and from there, in a curve over the rear axle, to the end of the car. In the frame, the engine or the entire engine block is suspended at three points in rubber blocks. At a speed of only 3800 rpm, it delivers a guaranteed average output of 30 hp - a value that alone says nothing because the course of the torque or power curve over the entire speed range is important. How favorable this is is shown by the behavior of the motor in practical operation, i.e., in its liveliness and elasticity even at lower and medium speeds.
Transmission
The flywheel at the end of the crankshaft has a dry single-plate clutch that transmits power to the gearbox. In order to achieve the highest possible load on the driven front wheels on the one hand, and to concentrate the entire engine close to the drive axles on the other, the arrangement in the light metal cast clutch/gearbox housing (Fig. 5.2-5) is such that the differential with two lateral outputs is placed in the middle the bevel gear. Behind the differential is the four-speed gearbox. Finally, the freewheel is located at the end of the housing.
The power flows from the clutch over the differential shaft into the gearbox main shaft, from there via the respective gear set to the secondary shaft, which carries the drive pinion for the differential ring gear. The four forward gears are designed in such a way that the first and second gears (and of course also the reverse gear) have tooth shifting by means of shiftable ratchet wheels, while the third and fourth gears use helical gears that are permanently engaged and shifted with a claw sleeve.
The clamping roller freewheel, which can be locked by a hand lever below the steering column, is very powerfully dimensioned. The locking required for reverse gear is carried out automatically by the shift rod guide located on the side of the gearbox housing. The shift lever is moved horizontally and vertically to the various shift levels by a hand lever located in the middle of the dashboard and within easy reach - similar to the one used in the F8. The lubrication for the differential gears as well as the freewheel is made by filling with gear oil, i.e., no longer by the grease/oil mixture used in the F8. The carden shafts are mounted through the side of the gearbox housing as an extension of the differential shafts, encapsulated within rubber joints, similar to those of the F 8. The driving force is transmitted through the grooved inner part of the cardan shafts through to the wheel hubs, as per the well-known and proven F8 model.
The F9 is also a front-wheel drive car with all its well-known advantages, which have been increased by the more favorable load distribution. This means that the entire interior of the car remains free of transmission parts. It is obvious that the concentration of the entire engine in the front part of the vehicle is also advantageous in terms of noise and, from this point of view, underlines the superiority of the F9 over rear-wheel drive vehicles.
The Chassis
At first glance, when looking at a picture of the chassis (Fig. 5.2-3), it seems as if the engine was simply hooked into a normal F8 frame: unmistakable is the front transverse spring, the bulging, stiff tubular profile frame and the rigid rear axle with the overhead transverse spring, which results in the so-called "floating axle" [an arrangement in which the structure "hangs on the spring", so to speak and therefore does not show any lateral inclination in curves].
While the arrangement of the rear axle including springs, shock absorbers and trailing arms is absolutely the same as that of the F8, the front suspension is significantly different. The rack-and-pinion steering with the tie rods has moved behind the spring. Especially important is that the lower wishbones no longer use the shock absorber axle as a mounting, but rather are separately attached on the frame, forming a much wider triangle, while the spring damping is carried out by hydraulic shock absorbers that are hinged to one of the wishbone arms.
Driving at high speed without risk of course also requires a brake that gives the best deceleration. The F9 was therefore equipped with a hydraulic brake, which is normal in terms of the design of the wheel brake cylinder, but has a completely new design master brake cylinder, which is again a product of the IFA. The handbrake acting on the rear wheels works with a cable. The handbrake lever is arranged in such a way that it does not hinder getting in and out and is nevertheless within reach.
The Body
When designing the body (Fig. 5.2-1), new paths were broken compared to the previous types, both in terms of material, shape and equipment. The synthetic leather-covered plywood body of the F8 was replaced by an all-steel construction, which is mainly required for export. What is also appealing is the surprisingly spaciousness of the car, the comfortable seating arrangement (front seats can be moved individually), the convenient steering wheel position and the proximity of all operating levers.
The latest development of the IFA F9 is reflected in the increase in output for this 3-cylinder two-stroke engine from 28 to 30 HP. In addition, the IFA F9 is also available as an elegant four-seater convertible and as a station wagon. This type, which has been followed with particular interest at home and abroad, has now moved even further into pioneering developments since its body is made with plastic components as standard.
The test car with a plastic body has passed the toughest test drives of 200,000 km (Fig. 5.2-4).
In 1952, the collective Kurt Lang, Ing. Fritz Hans, Erich Klaus, Ing. Wilhelm Ladewig, Ing. Wolfgang Barthel and Ing. Josef Schallenberg received the second-class national prize for the development of the molded body. Bestal was used as the material for this molded body. It is inexpensive, light, sound-absorbing, heat-insulating and replaces sheet steel. When using this new material, one wants to proceed in stages, namely first the rear fenders, then the lid of the trunk and finally the entire body are to be manufactured from Bestal. It should be mentioned in particular that this is not a "substitute material", but that new ways of using new materials in bodywork have been taken.
Senior Engineer, Siegfried Rauch
The Development of the IFA F9 - https://dkwautounionproject.blogspot.com/2020/07/the-development-of-ifa-f9.html
Basic Problems of the GDR Motor Vehicle Industry - https://dkwautounionproject.blogspot.com/2020/12/basic-problems-of-motor-vehicle-and.html
Kraftfahrzeuge Technik Volume 9 - https://dkwautounionproject.blogspot.com/2020/12/1952-kraftfahrzeug-technik-vol-9.html
IFA F9 Repair Manual - https://dkwautounionproject.blogspot.com/2019/07/1956-ifa-f9-drivers-manual-with.html
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