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DonL:
Most of Junkers engine development department from 1937 to 1941 was working on the Jumo 211 and Jumo 222
The big Jumo 222 for the Bomber B has priority A wide away from the Jumo 213 which was a very very low priority engine for Junkers from 1937- first half 1941.
Not until the realy big problems of the Jumo 222 crankshaft and the stopping of the whole project through the RLM at the end of 1941, Junkers shift major development powers to the Jumo 213.
Here you can see that the Jumo 222 costs 3-4 years development time of the Jumo 213.
When the Jumo 211 entered production in the late 1930s it used an unpressurized liquid cooling system based on an "open cycle". Water was pumped through the engine to keep it cool, but the system operated at atmospheric pressure, or only slightly higher. Since the boiling point of water decreases with altitude (pressure) this meant that the temperature of the cooling water had to be kept quite low to avoid boiling at high altitudes, which in turn meant that the water removed less heat from the engine before flowing into the radiator to cool it.
By contrast, the 1940 Daimler-Benz DB 601E used a pressurized coolant system that ran at the same pressure regardless of altitude, raising the boiling point to about 110°C. This allowed it to use considerably less water for the same cooling effect, which remained the same at all altitudes. Although otherwise similar to the Jumo 210 in most respects, the 601 was smaller and lighter than the 211, and could be run at higher power settings at higher altitudes, making it popular in fighter designs. The 211 was relegated to "secondary" roles in bombers and transports.
Junkers was not happy with this state of affairs, and started their own efforts to produce a pressurized cooling system as early as 1938. Experiments on the 211 proved so successful that it became clear that not only could the engine be built smaller, but could be run at higher power settings without overheating. Additional changes to strengthen the crankshaft and add a fully shrouded supercharger for increased boost resulted in the Jumo 211F model, which delivered 1,340 PS (1,322 hp, 986 kW) at 2,600 RPM, up from 1000 PS at 2,200 RPM in the first version 211A.
But this was only the beginning. After redesigning the engine block to a smaller external size to suit the increased cooling power - while keeping the same 150 mm x 165 mm bore/stroke figures, maintaining the 35 liter displacement of the Jumo 211 series - and then further increasing boost settings on the supercharger, the resulting 213A model was able to deliver 1,750 PS (metric hp) at 3,250 RPM. This made it considerably more powerful than the corresponding DB 601E which provided 1,350 PS, and about the same power as the much larger DB 603.
The 213A first ran in 1940, but experienced lengthy delays before finally being declared "production quality" in 1943.
AFAIK the Jumo 213 was smaller, lighter, and more fuel efficient than the DB603, which hadn't reached 100 hours between overhaul in 1944 historically, unlike the Jumo 213, which was in fact pushing 2000hp with its 4 valve variant.Most German aircraft designers preferred Daimler-Benz V12 engines over Junkers V12 engines. So if RLM decides to fund a larger V12 I think the DB603 engine makes more sense. Especially since DB603 prototype was running during 1937 at time of funding cancellation.
My solution.
Daimler-Benz does not get to compete in V24 engine program (i.e. no DB604). Instead DB603 engine program will be fully supported.
Jumo 211 engine program is fully supported but there will be no Jumo 213. Instead Jumo 222 engine program will be fully supported.
During 1937 it's impossible to know how good DB603 and Jumo222 engines will be. Funding both programs means Germany will not be putting all their next generation aircraft engine eggs in one basket.
Nor did they have foreknowledge that the DB603 would work; for some reason historically in 1937 they didn't like the DB603's chances, so cut funding. IMHO it probably had something to do with the Jumo 222 offering a better HP output and better fuel consumption rate (theoretically), while the large displacement of the DB603 and high fuel consumption/power to weight ratio compared to other options made it too risky to work on. Historically it only got funding due to a glut of funding resulting from the start of the war and no downside to funding it as an outside potential backup.Jumo 213 did not have a running prototype during 1937. So unless RLM has a crystal ball for viewing the future there's no way to tell how good Jumo 213 would be.
If 1937 RLM does have a crystal ball they should make a beeline for DB605D engine and cancel everything else except jets.
Most German aircraft designers preferred Daimler-Benz V12 engines over Junkers V12 engines. So if RLM decides to fund a larger V12 I think the DB603 engine makes more sense. Especially since DB603 prototype was running during 1937 at time of funding cancellation.
My solution.
Daimler-Benz does not get to compete in V24 engine program (i.e. no DB604). Instead DB603 engine program will be fully supported.
Jumo 211 engine program is fully supported but there will be no Jumo 213. Instead Jumo 222 engine program will be fully supported.
During 1937 it's impossible to know how good DB603 and Jumo222 engines will be. Funding both programs means Germany will not be putting all their next generation aircraft engine eggs in one basket.
If that's the strategy then DB606 is the way to go for a bomber engine as it was tested during 1937 to 1938. Even the 1938 version produces over 2,000hp and that will only increase as DB601 engine becomes more powerful.
You could cancel V24 engine, Jumo 213 and DB603. Just spend some money to develop a reliable DB606 "power egg" configuration which would be standard for any aircraft powered by this engine.
If that's the strategy then DB606 is the way to go for a bomber engine as it was tested during 1937 to 1938. Even the 1938 version produces over 2,000hp and that will only increase as DB601 engine becomes more powerful.
You could cancel V24 engine, Jumo 213 and DB603. Just spend some money to develop a reliable DB606 "power egg" configuration which would be standard for any aircraft powered by this engine.
So if the Jumo 222 is not started and the Jumo 213 is the priority, it reaches 1944 levels of readiness by Spring 1942 in this scenario. That's at 1750 PS with 87 octane fuel and 3 valve cylinders. The DB603 is not given priority. Instead the progress on the Jumo 213 means that not only is Jumo 211 production shifted to the 213, but the Ostmark engine facility starts producing them in 1943 when it was historically supposed to start producing Jumo 222s (there is no diversion in that direction in this scenario). So in 1942 its widely available, but still requires phasing out the 211, which won't be done fully until some time in 1943. In the meantime in 1943 the 4 valve version is phased in, which IIRC produced nearly 2000hp on 87 octane fuel. With C3 fuel and 4 valves it reached IIRC 2100 PS, which was about the output of the Jumo 222.The Jumo 213 is a natural development out of the Jumo 211 with all learned issues about pressurized cooling system, higher RPM and more ata.
The engine (bore/stroke) is absolute the same as the Jumo 211, the engine block differs through the cooling lines and minor other issues.
Without a development of the Jumo 222, which is a complete other engine, also with other engineering problems, Junkers Jumo could start with the development of the Jumo 213 from the base of the Jumo 211 with high priority at 1938.
As you said from the timeline, to me it is more a matter of fact, that we have seen the Jumo 213 introduced in mass production beginning or mid 1942 with near the original power rating without any advertisement and development of the Jumo 222.
This would have significant impact on the FW 190 D and the Ju 88 in all variation, especially the Ju 88 G nightfighter series.
The development of the "long nose" FW 190 was on a good way or near ready at 1942, so to my opinion we would have seen the FW 190 D9 beginning 1943 as also the Ju 88 with Jumo 213 engines.
Such a scenario, what is to my opinion very real, would have the benefit, that the LW had at realtime the right answer to the Spitfire IX with the Merling 60 engine and a real performance nightfighter right at time.
So if the Jumo 222 is not started and the Jumo 213 is the priority, it reaches 1944 levels of readiness by Spring 1942 in this scenario. That's at 1750 PS with 87 octane fuel and 3 valve cylinders. The DB603 is not given priority. Instead the progress on the Jumo 213 means that not only is Jumo 211 production shifted to the 213, but the Ostmark engine facility starts producing them in 1943 when it was historically supposed to start producing Jumo 222s (there is no diversion in that direction in this scenario). So in 1942 its widely available, but still requires phasing out the 211, which won't be done fully until some time in 1943. In the meantime in 1943 the 4 valve version is phased in, which IIRC produced nearly 2000hp on 87 octane fuel. With C3 fuel and 4 valves it reached IIRC 2100 PS, which was about the output of the Jumo 222.