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| The BMW801 engine The BMW801 is the first double star engine conceived and manufactured in Germany. This engine was, at the beginning, a project of the firm Bramo, the Bramo329, this company was repurchased by BMW. The design then the manufacture of the first BMW801 began in 1938 pennies the cane of the ing. Duckstein. The first bench tests were carried out in April 1939 and the series production was launched in December although the engine is not yet completely at the point. The first engines were delivered middle 1940. There were 22 versions of this engine; 11 were really produced, 4 others did not exceed the test bench and 7 remained with the state of project. At the end of the war, approximately 21000 engines BMW801 all types confused were manufactured. From 1942, at the request of the RLM, the engines were delivered with all its accessories and the part before hooding, from semi-1944, they was in general delivered "ready to go up"; I.e. that they were equipped with all their accessories, the conduits and deflectors of cooling under pressure, the ventilator to front, all the engine cowlings and their supports, the radiators and tanks, the exhausts and even the engine mount.Versions A of Fw190 equipped with a BMW801 were most prolific, also I go here, to detail a little more this engine.  One of the innovations engine BMW801 is the system of forced cooling. Supplied with a ventilator with front, it put the driving compartment under pressure. The ventilator was pulled by the propeller shaft. This ventilator allowed a more effective cooling during the operations at low speed and especially in rise. What made it possible the FW190 to assemble almost full throttle much longer than the other apparatuses which were obliged to go up less quickly not to overheat or to make stages to cool the engine. The compressed air in the driving compartment allowed the cooling of the engine and the oil radiator. This last annular and was located in the leading edge of the engine cowlings. Part of the air under pressure was sent forwards guided by deflectors through radiator then left outside by an adjustable slit. This slit was actuated by means of a simple ring of order on the throttle lever. The temperature of the cylinders was adjustable using another ring located it also on the throttle lever on A-3 then replaced by a serrated roller located in bottom at the medium of the dashboard on the A-8 version.Another innovation related to the development of this engine is the "kommandogerät". This device had as a function to deal with the management of the engine. The pilot actuated the throttle lever and hop! The "kommandogeräte" dealt with the remainder.  This device managed; the compressor, the step of the propeller, advance with lighting, the idle, richness and its corrections according to altitude etc. This device had a disadvantage, it required fingers of fairy during maintenance because the adjustments were delicate. They were generally carried out by a specialist trained by BMW, and moreover, it was very sensitive to the shocks. The mechanics quickly learned how to protect it by a thick layer from rags or to work "carefully" in the vicinity. This device proved nevertheless extremely useful to release the pilot of a great part of the management of the engine. This device had a development and a development long and tiresome. An anecdote read in a work, quotes Kurt Tank who, in top of a loop, throttle retarded during a trial flight, east left in gimlet following an inopportune and brutal release the compressor to 2600 meters altitude. (the device was to engage the compressor between 2600 and 2900 meters of altitude according to the request posted with the throttle control lever). Although it lands then without problem, K.Tank put "warmly" remains about it the engineers of BMW to re-examine the device! The air supply of the engine was carried out through channel of admission equipped with a filter and, to guarantee its operation at low the temperature and in frosting condition, of the valves opened thanks to the depression generated in the conduit during the icing of the filter. All the versions of series of the BMW801 have 14 cylinders in 2 stars of 7, a race of 156mm and a boring of 156 mm, and were cools by air. Throughout the war, the production at summer improved and optimized to reduce the costs. In 1940 a naked BMW801 was worth 80700 Reichsmark, at the end of 1942 a BMW801 was worth 45000 ReichMarks including 3000 for the "kommandogerät" and 6400 for the remainder of the preparing. At that time it took approximately 16000 working hours to pass from rough metal to the engine ready to mounting. In addition, the operating mode of the supplies engines in Luftwaffe imposed the delivery of the engines ready to go up. This mode of delivery was called "Motoranlage" and allowed a faster change of the engines by the presence of a certain number of equipment already installed. From 1944, this logic was still improved by the delivery of the engines complete with pipes of exhaust, and caps. These sets were named "Triebwerksanlage" Par example: the engines of version A were delivered under designation BMW801MA (M for motoranlage). Up to now it is logical! The D-2 versions were they, delivered under designation BMW801MG, the few specimens of the version E, delivered under designation TG or TH (T for Triebwerksanlage), is added to it the versions with turbocompressor whose naked designations started with T These various names cause much confusion, I am not even me not certain of all designations. There is not to date any work sufficiently detailed on this word family, information presented here are the result of the compilation of the some works which speak about it. I wish in the near future to have the resources necessary to carry out research with an aim of clarifying the various names naked and equipped as well as the chronology with the alternatives. Below a table recapitulating principal information on some versions of this engine and their performances. After the table you will find the detail version by version of information which I could glaner during my research. Attention certain information comes only from one source and, if they appeared sufficiently interesting to me and credible to be diffused, they can be of doubtful validity.
The BMW801A engine | |||||||||||||||||||||||||||||||||||||||||||||||||
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With 41,8 liters of cubic capacity, a compression ratio of 6,5, functioning with an octane 87 gasoline (B4 type), this version developed approximately 1600 CV. The engine was equipped with a centrifugal compressor on 2 floors which had a compression ratio of 5,07 below 2600 meters and 7,47 above. To be exact, the mode of the compressor changed between 2600 and 2900 meters according to the request posted by the pilot with the throttle lever, and 2900 meters in all the cases. The "kommandogerät" managed it compressing. Cooling was ensured by a ventilator with 10 blades pulled by the tree propeller. Equipped with a propeller with variable step VDM with 3 blades involved through reduction of 0,54. The adjustment of the step of the propeller was managed electrically. The engine turned clockwise (seen cockpit). This version was produced from 1939 to 1943 under designation BMW801MA.
This version intended for the hunters, did not have that little difference with version A. the adjustment of the step of the propeller was hydraulic instead of electric, a play of electrically controlled lever made it possible to regulate the air flow around the engine and in the oil radiator to control the temperatures of them. This version had additional deflectors to ensure the cooling of the weapons of caps. The C-0 under-version had a ventilator with 10 blades and starting from the under-version C-1, the BMW801 received a blower with 12 blades. Bmw80ç-1 developed 1560 Cv, varying it C-2 1600 Cv, all two used standard gasoline B4. The BMW80Ç weighed, with its functional equipment, 934 kg, and, completely equipped, 1055 kg and was 2,006 meters long without the propeller. 
Improved version from C variant, the BMW801D-0/1 had a more powerful centrifugal compressor, which increase the pressure of admission to 1,39 hPa ABS (instead of 1,27 in absolute pressure on A and C!), the pressure of admission was still improved with the D-2 sub-version with 1,42 hPa ABS. The versions D of series used gasoline with an octane number of 95 (C3 type), and delivered 1700 CV to 2700 rpm on takeoff for the D-1. version This version comprised many improvements compared to the versions C the D-2 type developing 1730Cv with takeoff, is in fact the first really reliable version of the BMW801. An engine called D was used as prototype with a version not developed of compressor on 3 floors. Another engine, indicated Ds was a prototype for version M/TM in fact D-2 equipped with a turbocompressor which was to develop 2000 CV with takeoff. The series production D-2 started with semi-1941 and continued until the end of the conflict. 
the version G resulted from C, it was a prototype slightly modified (deflecting simplified etc.) intended for the bombers. the engine had weaker report/ratio of reduction to actuate larger propellers. The version G and its descendants were produced the semione and continued until the end of the conflict. 
Developed starting from the version C, the version L has engine controls entirely hydraulic and developed 1600 CV. Redésignés later ml, this version were intended for the planes of attack or tropicalized. Version ml seems to be produced de1939 at 1943 then TL developing 1730 CV on the basis of prototype G since 1944. 
Version similar to the J, delivering more than 2000 CV on takeoff and approximately 1700 to 12000 meters. Seem to be produced in small number under designation TQ (not of known figure of production). The versions J, M, N and Q are all of the developments intended for versions of high altitude of Fw190. The production as of the these versions had to be marginal because expensive and greedy out of raw materials strategic.