wiking85
Staff Sergeant
http://www.ww2aircraft.net/forum/engines/jumo-213-what-took-so-long-39029.html#post1077567
Is it true that had the Jumo 222 not been focused on the Jumo 213 could have been ready 3-4 years earlier? Assuming we mean the 1944 wide service introduction, that would mean about a 1941 introduction for the Jumo 213, though probably not at the same HP rating as the 1944 version. That seems a tad early IMHO, even considering the first version of the Jumo 213 was available in 1943 and the Jumo 222 did such up engineering resources that the needed to get ready.
Technologically it doesn't seem that early though, considering that one of the major the major difference was the pressurized cooling system that Daimler had from the late 1930s for the DB601.
https://en.wikipedia.org/wiki/Junkers_Jumo_213
1942 seems like the more likely wide introduction date if we assume as similar start as historical happened. I guess we assume the Jumo 222 is either cancelled earlier.
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.
Is it true that had the Jumo 222 not been focused on the Jumo 213 could have been ready 3-4 years earlier? Assuming we mean the 1944 wide service introduction, that would mean about a 1941 introduction for the Jumo 213, though probably not at the same HP rating as the 1944 version. That seems a tad early IMHO, even considering the first version of the Jumo 213 was available in 1943 and the Jumo 222 did such up engineering resources that the needed to get ready.
Technologically it doesn't seem that early though, considering that one of the major the major difference was the pressurized cooling system that Daimler had from the late 1930s for the DB601.
https://en.wikipedia.org/wiki/Junkers_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.
1942 seems like the more likely wide introduction date if we assume as similar start as historical happened. I guess we assume the Jumo 222 is either cancelled earlier.