1954 CIA Information Report - DKW (IFA) Car Production

Central Intelligence Agency
Country: East Germany
Date: 23 March 1954
Subject: DKW (IFA) Production
Pages: 1
Place Acquired: [redacted]

[Introduction redacted]


Production of the IFA DKW car, type F-9, had to be stopped in late November 1953, at least for the time being, because of the legal steps taken [redacted] in connection with litigation on the trade mark and patent infringements.

Comment: Auto Union GmbH had raised the litigation against the East German nationalized enterprise, IFA, over production of the IFA F9. After Germany was divided after the Second World War, Auto Union AG found itself split apart. Its factories were in East Germany and nationalized in 1948. A new company was established in the Western Zone and built up from scratch. Although the East German successor of Auto Union AG, IFA, assisted and even partly funded the new western company, political tensions between the East and West resulted in the companies turning to outright rivalry. IFA was able to restart vehicle production in 1948 and soon re-established connections with DKW sales agents outside Germany. This horrified the new DKW company but they were not able to get a vehicle into the market until 1949. IFA began exporting the F9 in 1950. DKW did not have the F9's triple cylinder engine and substituted a new version of the prewar twin-cylinder engine for their rival F89P. The two vehicles were similar, but substantially different. It was only after DKW managed to obtain a prewar triple test engine and reverse engineered it, that they were able to put their own version of the F9 on the market as the F91. The IFA F9 and DKW F91 were thus direct descendants of the 1940 DKW F9.

After initially slow production of the IFA F9, production was transferred to the Eisenach BMW plant in 1953 and earlier production defects addressed and production at pace commenced. DKW saw this as a direct threat and began raising legal challenges to block IFA sales in the west. DKW claimed patent infringement as the successor of Auto Union AG. BMW had raised similar challenges against the BMW Eisenach plant in 1952, effectively blocking the company out of the western market. For the East German companies EMW and IFA, there was no way to get a fair hearing in western courts, so both withdrew from the west. Eisenach continued manufacturing the IFA F9 for two more years but exports were directed east and north to Scandinavia. In 1955 the car was completely remodeled into the much more modern Wartburg 311, sidestepping the patent issue and reopening the door to western exports. DKW would continue with the older styled F91 and its successors through to 1964, by which time it was quite old fashioned.

1938 DKW SB350 Restoration Update November 2024

After whinging to my club mates about some of the issues I was having with the bike, Wayne from Classic Gasoline (who worked on my Tatra and DKW at various times) said bring it around and we'll have a look at it. Wayne has Vape ignition on several of his bikes and he felt he would be able to quickly nut out the issue.

It's much easier to solve these problems quickly when you have adult supervision. Kim and Gavin get stuck into it.

After some fiddling around with the Vape, a good, strong spark was achieved. This highlighted there were problems with the carburetor.

The carburetor was removed and cleaned with an ultrasonic cleaner - note the underlying bronze content of the Amal carb is exposed. The needle jet was misplaced and needed to be refitted. This was undoubtedly caused when I was trying to refit the choke slide. The choke itself was revealed to be a problem as the cable works in the reverse direction you would expect. What looks like 'choke off' is actually 'choke on.' This would explain some of the hard starting and choking out issues. Additionally we noted that the choke always wants to go 'on', springing back into the 'on' position by itself. There is a spring issue there to resolve.

With the carb largely sorted out (the choke spring still to be fixed), the engine would fire up easily and run but after a few minutes the carb would silt up with rust and dirt from the tank. Kim took the tank back to his workshop to have it cleaned up.

Electrical engineer Gavin set to work on the bikes confusing electrics. The bike is currently set up with the electrics running off the Vape magneto (no battery), but we've decided to fit a battery and kill-switch and wire in the horn and brake light. We are using the new wiring harness from https://www.motorradmeistermilz.de/
Once those jobs are done, the bike should be able to run. Everything else is mainly cosmetic - is fitting the chain guard and the speedometer cables. This where it pays to be in a club where you have access to people with actual, practical skills. It would have taken me ages of hit-and-miss, trial-and-error, repairs, with no guarantee that I'd be on the right path. Wayne, Kim and Gavin each have their specific skills and experience and were able to quickly identify the issue and the best path forward. Thank you guys!

Step One of the restoration effort: https://dkwautounionproject.blogspot.com/2024/08/1938-dkw-sb350-restoration-progress.html
Acquisition: https://dkwautounionproject.blogspot.com/2024/07/1938-dkw-sb350.html

1947 NAMI DKW Sonderklasse Review

Like all the Allies, the Soviet Union acquired technology and machinery from Germany after the Second World War. All technology was evaluated and reports circulated with its assessment. The Scientific Research Institute for Automobile technology (NAMI) received numerous vehicles for analysis. This partial (and poor condition) 1947 report analyzes a 1938 DKW Sonderklasse. By this time, the Sonderklasse was long out of production so the report did not make any particular recommendations, although we can't know for certain as many pages are messing. For comparison of a full report, check out this 1948 evaluation of a post-war Czechoslovakian Tatra T87. https://tatrat600.blogspot.com/2024/10/1948-nami-tatra-t87-review.html

1938 DKW Sonderklasse study by Ministry of Automotive and Tractor Quality Soviet SSR
State Order of the Red Banner of Labour
Scientific Research Automotive Institute

Introduction – Pg 1
Brief Specification – Pg 3
Test results:
1. Dimensions, low points and maneuverability - Pg 5
2. Weight data and centre of gravity height - Pg 7
3. Economy - Pg 8
4. Dynamic - Pg 10
5. Evaluation of body comfort, visibility and ease of control - Pg 13
6. Reliability of operation of individual units and vehicle equipment - Pg 14
Findings - Pg 16

General views of the DKW car

NAMI 1938 DKW Sonderklasse

ANNOTATION..

to the report on the testing of the DKW Sonderclass automobile, manufactured in 1938

The work covers laboratory and road tests to determine the dynamic, economic and other operational qualities of the automobile, as well as operational attempts with a mileage of 21,000 km.

In addition, the scope of the work performed included: drawing up technical characteristics, determining overall dimensions, clearances, maneuverability parameters, weight data, assessing the comfort of the body, visibility, ease of driving and reliability of the units.

The report provides comparative material on some small-capacity cars from other companies.

Based on the test results, conclusions were made about the operational qualities of the car and its reliability.

The technical characteristics given below almost completely correspond to the data published in 1937 in for the model “[blank]". Based on this, it can be assumed that this car model belongs to the production of 1937-1938.

The purpose of the tests was to determine the main design parameters, establish indicators for economy, aerodynamics, comfort and other driving and operational qualities of the car, as well as determine the reliability of its individual units during the tests.

The test car had a mileage of about 15,000 km before the tests (according to the kilometer counter).

By the time the laboratory and road tests (economy and dynamics) concluded, the total kilometers was 30,000 km.

In this regard, the results obtained for economy and dynamics are characteristic of a certain "average operational" rather than "parade" condition of the car, usually revealed during testing of new vehicles.

The DKW compact car has a 4-cylinder two-stroke V-type engine with two piston-type scavenging pumps, each of which is combined into a block with two working cylinders.

The working process in the engine takes place according to the scheme shown in Fig.4

Fig.4 Scheme of operation of the purge pump

The cylinder block is V-shaped, with the arrangement of cylinders at an angle of 90c, has a connector rod along the plane of the crankshaft. The left and right halves of the block are connected by bolts (figure 5).

Fig.5. Double block of cylinders. Bottom view

The design of the connecting rod and piston group and the crankshaft is shown in Fig.6. The shaft is located on two bearings. Bearing shells are made in the form of bushings. The crank of the connecting rods of the pistons of the scavenging cylinders is located at an angle of 90° to the cranks of the connecting rods of the working cylinders.

Fig. 6. Connecting rod and piston group

Note, the captions in the picture from left to right: Supercharger piston, supercharger seals, oil scoop, working piston.

Brief technical characteristics of the “DKW” passenger car
1. Engine type - gasoline, 2-stroke, with a scavenge pump V-shaped with an angle of 90 degrees
2. Number of working cylinders, diameter and stroke – 4 x 70 x 68.5
3. Working volume - 1054 cm3
4. The compression ratio in the working cylinders is 6:1
5. Power and speed - 32 hp at 3800 rpm.
6. Ignition - battery, 6 volts.
7. Ignition order - 1-2-3-4.
8. Power system - Carburetor "Solex", double, horizontal (Fig.7). Fuel supply by diaphragm mechanical pump.
9. Clutch - single disc, dry plate.
10. Gearbox - 4-speed with constant mesh on 3rd gear
Gear ratios:
1st gear - 4.06:1
2nd gear - 2.38:1
3rd gear - 1.47:1
4th gear - 1:1
Reverse - 5.28:1
11. Engine mounted at three points on rubber cushions.
12. Cardan shaft - tubular, open, with two soft semi-cardans.
13. Rear axle - type "Banjo". Gear ratio 4.88:1.
14. The front suspension is independent, having one transverse semi-elliptical spring below, and parallelogram levers with hydraulic shock absorbers on top (Fig. 8).
15. Rear suspension - one transverse semi-elliptical spring with two hydraulic shock absorbers.
16. Steering - installed on the left side of the steering mechanism is a worm with a sector.
17. Tires - 5.00-17
18. Brakes: Foot operated brake on hydraulic shoes acting on all 4 wheels. Hand brake centrally mounted, mechanical brakes acting on the cardan shaft.

Fig. 7. Carburetor "Solex" in section
1. Fuel filter mesh
2. Shut-off valve
3. Idle jet
4. Idle adjusting screw
5. Diffuser mount
6. Throttle stop vent
7. Diffuser
8. Main jet well
9. Main hitch

Fig. 8. Front suspension

Replacing the DKW fuel pump membrane - Update

DKW's are quite light-on for maintenance; there's no engine tuning, no changing of oil, but there are several jobs that do need to be regularly attended to. One of those things is replacing the fuel pump membrane.

DKW introduced a fuel pump with their first postwar passenger car, the F89P, in 1950. Prewar cars and the Schnellaster van had their petrol tanks mounted over the engine so simply used gravity feed, like in a motorcycle. The petrol pump selected by DKW used vacuum pressure from the crankcase to pull petrol from the petrol tank in the boot. It was a very simple and economical solution, but also a weak point as the membrane in the pump wears out or stiffens over time, reducing the pump's effectiveness. A perforated or leaking membrane can actually lead to catastrophic engine failure by letting petrol leak into the crankcase, flushing the grease from the bearings.

My DKW F94 began to exhibit hard starting about three months ago. The car simply wouldn't start without a dose of starting fluid if it hadn't been driven in the past fortnight; then in the past week; then it wouldn't start without it at all. I had fiddled around with the carburetor as that is often a leading cause of hard starting, but it did not help. This weekend I decide it was time to look at the fuel pump.

It's a very simple process to remove the false radiator grill - undo the two clips holding the grill in place and it lifts straight out. This provides easy access to the ignition timing and the fuel pump.

Next the fuel filter is removed, then the pipe to the carburetor. Two 17mm bolts hold the pump to the engine. Undo the bolts carefully so as not to damage the gasket.

Eight 6mm bolts hold the two pieces of the fuel pump together. After removing the bolts you can carefully separate the two sides of the fuel pump. There is a spring underneath the membrane and you do not want that flying across the garage as you need to put the spring back in correctly. If you place it on the wrong side or upside down, it will not work.

The membrane on my pump seemed okay. It flexed well and the spring was tight, but I replaced it anyway. You must take care when reassembling the membrane with the spring. You do not want to the spring to penetrate the membrane and of course the spring wants to fly. Aligning the membrane with the bolt holes also takes care. Re-installation is simple enough, reversing the process.

Although the old membrane seemed okay, a quick test run showed that that was, in fact, the problem. After only a few seconds of cranking the engine spluttered and caught and then was away. I was very happy! How long do the membranes last? In my experience they only last (reliably) for about three or four years before they begin to deteriorate. Fortunately, it's an easy repair, even for an amateur like me!

This was the type of membrane I used. It has a larger metal backing plate. There are different sized membranes between the different engines - 900cc, 1000cc and 780cc - so you need to check you're ordering the right one.

Update 4 November 2024 - Oh dear!!

Well, it seems I was wrong, wrong, wrong about the fuel pump membrane. After running well for several weeks, I took the car to a show - she drove magnificently, no problems at all - and then died on the drive home. I could not get the car to run at all more than about a minute before fuel starvation kicked in. As I have to drive over a long bridge to get home, I chose to have the car towed. Thank you RAC Roadside Assist!! https://www.productreview.com.au/reviews/99d09025-ed41-59bf-840f-7ea571f1b02d

At home I pulled the fuel pump apart again. I swapped out the membranes three times and each time the fuel flow was nil or a trickle. A trickle was the best I could do so I settled for that. At least I could get the started and moved in the garage where it wasn't blocking the Karmann Ghia. What was wrong?

When I consulted this diagram on DKW Hesse website I suddenly noticed that the fuel pump shows TWO springs, one on each side of the membrane. Two? My fuel pump has only ever had one. Clearly at some point in the past one of the springs was lost and never replaced. For whatever reason, the fuel pump continued to work but only just enough. Possibly the issue with hard starting was always the sole surviving spring stiffening up. I've been pointlessly changing the membranes which possibly freed up the spring a little, giving the impression of fixing the problem.

My friend Brendan O'Dell in New Zealand is sending me some new springs - THANKS BRENDAN. Brendan supplies Brazilian made parts to owners in New Zealand and further afield. I'll pop his website up shortly.

Arrived 21 November 2024. Third time is a charm!

And the problem is quite obvious when the pump was removed. The spring as it was in my pump was wrong to start with - the outer (small) spring was the mounted on the inside. It's quite obvious where they should go.

Like this - the spiral spring belongs on the engine side of the pump. The small spring fits on the outer side. The upper ends of both springs fit neatly into metal centre of the membrane. Another 30-40 minute job and it's done. The pump still only generates a weak flow, but its more consistent and is enough to get the engine running. I'll have to check in week or two whether I still have hard starting issues. In the meantime, a big thank you to Brendan O'Dell for his help. You're a champ!