Jumo 222 cost Jumo 213 3-4 years of development?

[Shortround6]

On a bomber the intercooler made some sense. Increased drag (and weight) on a bomber airframe is minimal. On a fighter it is much more debatable. How much more drag, weight and volume do you need for the intercooler vrs the HP gain? Most companies/engineers thought it was pretty much a "wash", whatever gain you got was canceled out by the drag. This is for engines using a low level of boost where the intercooler was good for less than a 10% increase in power or 3-4000ft of FTL.

 

[Shortround6]

What we don't know is how much either DB learned between 1937 and 1942 that they applied to the DB 603 when it did go into production ( I doubt very highly that the 1942 version was identical to the 1937 version) or what Junkers learned from the Ju 222 program that could be applied to the Ju 213. Anything on supercharger air flow? bearing technology or oil flow in bearings? Piston rings? any other metallurgy that might prove useful?

The 213 could certainly have been produced early but I am rather skeptical of claims that engines could have produced years earlier at the same power ratings that were introduced several years later.

 

[tomo pauk]

On a bomber the intercooler made some sense. Increased drag (and weight) on a bomber airframe is minimal. On a fighter it is much more debatable. How much more drag, weight and volume do you need for the intercooler vrs the HP gain? Most companies/engineers thought it was pretty much a "wash", whatever gain you got was canceled out by the drag. This is for engines using a low level of boost where the intercooler was good for less than a 10% increase in power or 3-4000ft of FTL.

The increased drag will, of course, cancel out a degreed of potential speed increase, depending how good or bad the intercooler's radiator is faired within the airframe. Where the increased power would be certainly worth it is the rate of climb, since there the small additional drag is of no concern, nor is the negligible increase of weight. We can see that in the numerous Spitfire IX vs. LW fighters comparisons - many times the Spit was not faster, but always come out as a better climber.

 

[wiking85]

Is one year earlier really that much of a change that would affect the power rating? As it was the Jumo 213 was pretty much ready by late spring 1943, but there was a long phase in due to bombing disruptions and lack of willingness to disrupt Jumo 211 production anymore than it already had been. Production schedules had been thrown off by the failure of the Jumo 222 project and the hodgepodge of other projects being phased in everywhere else.

According to Wikipedia:
https://en.wikipedia.org/wiki/Junkers_Jumo_213

The 213A first ran in 1940, but experienced lengthy delays before finally being declared "production quality" in 1943. Production was extremely slow to ramp up, in order to avoid delays in the existing Jumo 211 production. By the time the engines were available in any sort of number in 1944, Allied bombing repeatedly destroyed the production lines. Production of the A model was limited to about 400-500 a month for most of 1944/45.

An article at Aircraft Engine Historical Society states that it was running in 1942, but didn't complete the 100 hour requirement until March or April 1943 when it was given the go ahead for mass production; due to a variety of factors the phase in was long and it only had about 477 units for all of 1943; 1944 saw it getting into 4-500 units per month. The bombing of Dessau in 1943 surely didn't help. Having it ready in 1942 would mean there would be no issues associated with bombing yet, so it could phase in without issue or worry of the same sort of disruption in 1942. It wouldn't be hugely available, but it would be much more so than it was historically in 1943.

So moving things up 12 months I don't think would change the power output at all assuming all the engineering resources that went into the Jumo 222 are instead invested in the Jumo 213; if anything a 1941 version could be ready at lower horsepower and a 1750hp version would be ready by 1942. Arguably we could have the Jumo 213 entering production in 1941 as a 1600 hp engine without the major investments in the Jumo 222 and it would be steadily upgraded every year. If that was the case then things would be even more interesting in terms of engine availability in 1941-43 and could have very drastic changes for the air war.

@DonL: when we discussed Ostmark on some other threads about the Jumo 222 it seems that the building wasn't even complete until 1943 and the plans was to deliver the first Jumo 222s in 1943 originally. In fact the power station wasn't planned to be installed until some time in late 1942-early 1943. Disruption to the tooling when historically there was the switch from Jumo 222 to DB603 didn't help, considering the backlog of specialized machine tools.

I don't think its wrong to say that if the Jumo 213 was run early and not delayed by work on the 222, then Ostmark could have started tooling for the 213 in 1941 and been complete in 1942 some time. At that point it could make some deliveries and repairs, but wouldn't start major production until 1943; then it would be able to achieve the 800-1000 units per month that was planned. Other factories including Dessau could switch over earlier, so that the total capacity in 1943 would be in the several thousand units per month; IIRC the DB603 hadn't fixed most of its cooling issues until late 1943 (still not as good as the Jumo 213), so I don't see the benefit of putting it into production anywhere in 1942 if the Jumo 213 is working, smaller, lighter, more fuel efficient, easier to phase in, and has more immediate future potential. It would allow for greater standardization just having the one.

Without dive bombing reqs the Do 217 may have gotten a larger wing plus some weight savings in the fuselage (no stiffening for diving) so in the end it could have gotten a far better bomber and night fighter. Same with the Ju 88 series (proper internal bomb bay).
They could have gotten the Jumo 222 to work without these endless spec changes so 217 and 88 series could be powered by 1800-2000PS engines by 1943
I assume the Jumo 213 got some features developed for/with the 222, especially the improved supercharging sytem.

It would probably be ready sooner too without that dive requirement, which IIRC added at least 6 months to the aircraft's development; if we add in a 1941 1600hp version of the Jumo 213, then it would have been a viable aircraft in 1941 and could start phasing out the He111 and limiting the Ju88s role (i.e. canceling the Ju188). As to the Ju88 it was designed with that bomb bay before the dive requirement came, so it would still remain small due to being a speed bomber, not a medium bomber, as it was turned into. Here the Do217 could take on the role, letting a faster, cleaner Ju88 be the light bomber/speed bomber.

As to the Jumo 222 we agree, but without it we know we could have an early Jumo 213, which would have 1750hp by 1942 and with C3 fuel or the 4 valve cylinder by 1943 would have 2000hp too. So rather than waiting until 1943 to get what would likely be a difficult to maintain engine to start phasing into production, we could have a 2000hp Jumo 213 already phased in by 1943 and widely available, unlike the Jumo 222, which would only just be phasing in and working out the bugs. IMHO the Jumo 213 was the way to go.