Photo: Bundesarchiv


Bf 109 F-4/Z during an oil refill. The aircraft has circular wheel wells, a larger compressor intake and

a VDM 9-12087A propeller with wider propeller blades.

DB 601E

The further improvement in the performance of

the DB 601E engine was not achieved by further

increasing the boost pressure or the octane

rating of the engine. The DB 601E engine actually

reverted to the easier to produce B4 gasoline

with an octane rating of 87. The compression

ratio was 7.0:1 on the left side cylinders and 7.2:1

on the right side, and was thus lower than the

DB 601N. The cylinder bore and stroke were the

same as in the DB 601A and DB 601N, bore being

150 mm and the stroke 160 mm. As a result, the

displacement was also the same at 33.9 l. That's

about all that remained the same. There were

a lot of new and modified parts: a new engine

block, metering pump, boost pressure regulator,

injection pump drive housing and mixture

regulator for the injection pump, new reinforced

connecting rods, rocker arms, connecting rods,

new intake manifold and rebuilt engine cylinders

with larger intake manifold and modified valves.

Using an emergency engine boost pressure of

1.42 atm, at 2700 RPM, the highest output was

1,420 hp (1,440 PS) at an altitude of 2,100 m and

1,331 hp (1,350 PS) at sea level.

Combat power at 1.30 atm boost pressure, 2,500

RPM was 1,262 hp (1,280 PS) at 2,100 m and 1,183

hp (1,200 PS) at sea level.

The development of the new version of the DB 601

engine was long and rather complex, starting

at the end of 1938, with series production of

the zero series of 180 units (later increased to

290 units) beginning at the Werk 90 factory in

Berlin-Marienfeld in the second half of 1940.

Then, in January, production at the Büssing

factory in Braunschweig and Henschel in Kassel

was initiated. When the engines were introduced

into service, they had cooling problems, which

led to a limitation of the maximum permissible

engine power during take-off and climb. There

were also problems with the life of the piston

rings and the bronze valve bushings. There were

also problems with the spark plug cables, which

quickly wore and burned out. For these reasons,

most engines had a service life of only 50 hours,

with few engines reaching 100 hours, which was

a far cry from the expected 100 service hours

to a midlife overhaul and 200 service hours to

a general overhaul. Back in May 1942, during

a joint inspection by the procurator of the

Daimler-Benz company, von Berg and Colonel

Galland (at that time in the capacity of the Fighter

Air Force Inspector-General der Jagdflieger),

a critical situation was discovered for the units

on the Eastern Front, armed with the Bf 109 F-4,

stemming from the unsatisfactory condition

of the engines. Heavy engine wear threatened

to ground a large part of the machines in

operation and significantly reduce the combat

capability of the fighter units. It can be seen

from this that although there was a remedy by

modifying the problematic components, such

as the introduction of steel valve bushings and

vented wiring harnesses, this remedy was time

consuming and engine problems accompanied

the Bf 109F-4 for practically the entire first year

of their service. That is, the entire time of their

front-line service, because in the summer of

1942 the first Bf 109 G-2s with DB 601A engines

were already making their way to Luftwaffe

fighter units.

Coolant Radiators

Due to the anticipated use of the more powerful

DB 601E engine, new radiators were developed

for the Bf 109F and the engine cooling system

Photo: Edward D. Beneš archives, Aviation archives of Northen Bohemia


Two synthetic aviation fuels

were used in the DB 601 series

of engines. Both were produced

from brown coal by FischerTropsch. The final mixtures,

depending on the required

type of fuel, were produced

in the so-called WiFo depots


according to the requirements

of the individual branches of

the armed forces.

B4 Flugmotorbenzin was

a synthetic gasoline with

an octane rating of 87. It

contained tetraethyl lead and

25% aromatic additives. It was

colored dark blue, and it was

graphically symbolized by a

yellow triangle outlined in


INFO Eduard

white with the number 87 or

B4 in it. It was the synthetic

equivalent of B2 gasoline,

produced from petroleum.

C3 Flugmotorbenzin was

a synthetic gasoline with

an octane rating of 100. It

contained tetraethyl lead and

45% aromatic additives. It

was colored dark green, and

it was graphically symbolized

by a yellow triangle outlined in

white with the number 100 or

C3 in it. This was the synthetic

equivalent of C2 gasoline,

produced from petroleum.





explanation of the meaning

behind the octane rating,

please see.

Sudetendeutschen Treibstoffwerke AG Brüx, located between Most and Litvínov in northern

Bohemia, was the third largest producer of synthetic gasoline in Germany and the occupied

territories. Construction of the plant began in May 1939, and the first train of synthetic gasoline

was dispatched from STW Brüx on December 15, 1942. Albert Speer, Reich Minister of Armaments,

attended the opening ceremony. The plant was producing up to 50,000 tonnes of synthetic fuel per

month at full operation. In the last year of the war, after the Allied bombing offensive against the

German fuel industry began, it became a frequent target of Allied air raids, mainly led by the

8th USAAF from Britain and the 15th Air Army from Italy. The first raid on this chemical plant on

8. USAAF carried out on May 12, 1944, and 12 more major American raids followed by the end of

1944. A heavy night raid was carried out by 231 Lancasters of RAF Bomber Command on January

16, 1945, virtually putting the factory out of action for the rest of the war.

June 2023