Time Machine ENGINE consultant!!!

[Burmese Bandit]

So: was there any HISTORICALLY PLAUSIBLE way for the Germans to have won, or at least fought to a draw, the aerial war in WW II ?

After reading about the entire design/production/gunpower/agility/speed/range/handling/numbers/ and a 1.0001 other tradeoffs and considerations regarding German airpower in WWII, an idea struck me.

An idea which may be perhaps too simple, yet fascinates me at how POSSIBLE it was.

The premise is this. The main problem of German aircraft of WWII was ENGINES. There was always a shortage of engines which were easy to produce, maintain, which had good reliability and were there in real time, not two years or more after they were needed. And because good, cheap, sufficiently powerful and reliable engines were in short supply, fighter designs were delayed, and the bomber and fighter groups got into arguments about who should get what engines.

So if one could PLAUSIBLY produce an engine that was available early in the war, had reliability and sufficient power, and was cheap enough to produce and rugged in battle and easy to maintain, all these problems could have been solved.

And I say...

What about a TEN CYLINDER TWO ROW BMW SCALE UP OF THE 132???

First, let's look at history.

We know that the nine cylinder, air cooled, single row 132 was one of the most reliable engines of WWII, with over 20,000 produced. We know that it was designed in 1928 and first came into production in 1933.

Now I ask: what if in 1928 the engineers at BMW were just a little bit bolder, and designed not a single row nine cylinder radial, but a ten cylinder double row radial?

IMHO the design work would have been just a little more complicated.

The engine would have suffered little or none of the cooling problems associated with double row radials, since the five cylinders in front would have had almost no obstructive effect on the five cylinders behind.

(For those on this forum who are not yet familiar with the design problems of air cooled radial engines, a brief explanation: All radial designs have to have an odd number of cylinders in each row. Thus the alternative to a ten cylinder two row engine would be a fourteen cylinder two row, or an even bigger eighteen cylinder two row engine. Once you get to fourteen cylinders the problem of engine overheating due to cooling air not reaching the rear cylinders starts to rear its ugly head, as indeed happened historically with the BMW 801. And of course if you go down the 18 cylinder route these problems increase.)

So let's say that design-wise, a ten cylinder two row engine was perfectly plausible and possible in 1928-1933. So we get one more cylinder, and a 30 liter engine instead of the 27.7 historical BMW 132 engine in 1933. So we have 11% more displacement and 11% more power. So what?

Well, we find that it fits a very interesting niche in the timeline.

In 1936 when the Luftwaffe was just beginning to expand, the historical BMW 132 was producing about 830 hp, or about 92 hp per cylinder. If we had 10 cylinders, that would make our Bandit 142 engine produce 920 hp in 1936.

1,000 is the magic number of hp for the engines powering the Heinkel 111 and Ju 87 and 88 prototypes during that time - the DB 600 series and the Jumo 211 early versions.



With only 8% less power, this ten cylinder air cooled radial could have competed well with the prototypes of the two engines powering the three bomber prototypes mentioned above. The slightly less power and the increased frontal area would not be too much of a problem for bombers, where most of the drag was from the fuselage anyway, and especially for the JU 87, which was specifically designed to be draggy so that not too much speed would build up during a dive.

Against the slightly reduced power and the slightly increased drag would come the benefits of battle ruggedness, for unlike liquid cooled engines, air cooled radials could take hits knocking out one or two or sometimes even three cylinders and still survive. They would also be more reliable - which was, BTW, why the US Navy carrier aviation inisisted that all their planes be powered by air cooled radials.

So now, our BMW company builds the twin row 142 and its little brother, the single row 141 engine. How does this engine family hold up in the timeline of power requirements of the war?

Let's look at our historical comparision, the BMW 132. At its height the nine cylinder engine produced up to 1,200 hp. Extrapolating to an extra cylinder, this means our notional ten cylinder could have produced 1340 hp, and its little brother up to 670 hp. This means the engine is competitive to historical luftwaffe bomber engines up to 1944. The Ju 88 A-4 which was in widespread use used 1340 hp Jumo 211 engines. The Ju 87Stuka in its most developed version used 1400 hp Jumo engines. Our developed 142 could well have replaced the Jumo 211 in both these roles.

BUT UNLIKE THE BMW 801 IT WOULD HAVE BEEN READY BY 1933 AND HAVE HAD THE LUXURY OF A LONG AND STEADY DEVELOPMENT PERIOD, SO THAT IT WOULD HAVE BEEN PRODUCING 920 HP BY 1937, 1000 HP BY 1939, 1100 HP BY 1940, 1200 HP BY 1941 AND 1350 HP BY 1942. THE BMW 801 WAS PRODUCING 1600 HP IN 1940, BUT TRUE MASS PRODUCTION DID NOT BEGIN UNTIL 1941.

IF THE NOTIONAL BANDIT 142 HAD BEEN PRODUCED INSTEAD, BY 1941 IT WOULD HAVE BEEN IN MASS PRODUCTION FOR FIVE YEARS ALREADY, AND PRODUCING 1200 HP WHICH WAS PERFECTLY ADEQUATE FOR TWIN ENGINE BOMBER DESIGNS AND STUKAS.

Which meant that fighter designs were now free to use the large number of DB and Jumo inline engines now freed for the duty of powering bombers.

So: the FW 190 Dora arrives in 1942 instead of 1944...with a lower power 1300 or 1400 hp inline engine, true, but it would have been easily competitive with its contemporaries, the Spit V and the P 40... and as 1943 and 1944 rolled around it would have gained the engine power being developed for the DB and Jumo engines, so that Mustangs arriving in early 1944 would have been greeted by not just the 109s but many hundreds of FW 190 Doras in their third year of development, with Jumo 211 mass produced engines of about 1500 hp. This would have given them a top speed of about 400 mph in early 1944. equal to the 109 G models but with much better handling and ease of flying. And the Jumo 213 engined versions just beginning to come off the lines in February 1944 instead of at the end of 1944.

Oh yes. And takeoff and landing and pilot saving from lesser crashes. Let's not forget that.

[Njaco]

Great stuff Burma but I believe there was one factor that was a MAJOR reason why it was lost for Germany - numbers.

The sheer numbers of aircraft available and being produced for the Allies was far beyond anything Germany could have overcome.

[tomo pauk]

Germany needed a 1500-2000 HP engines in pre-1943 era, not yet another 1000-1500 HP design.
So they need to bribe someone at Pratt & Whitney to bring them R-2800 blueprints.

Or start producing jet engines while they were not fighting Russkies & Americans, so the necessary raw materials could be obtained. And jet engines can use diesel, so farewell to expensive & flamable AvGas.

[Krabat42]

Nice idea, and technically sound as far as I can say. But absolutely out of the question in 1928 for several reasons:

1. BMW had just bought the license for the PW Hornet. There would be no money to develop a completely new engine, especially when a lot of the money earned with aircraft engines went into the newly aquired Automobile plant in Eisenach (ex Dixi).

2. Radial engines were not very common in Germany, especially not for the civil market (Lufthansa) which was the most important at this time (no real Air Force after the Treatry of Versailles). So making radial engines (and later giving up inline engines completely) was a great risk. That's why they bought the Hornet (and of course also because BMW could get a lot of experience which otherwise would have taken years to get).

I know this does not cover the technical aspects, but it's what I can say from my position (which is - even as it sounds like bragging - sitting behind a desk in the BMW Archives).

Krabat

[davebender]

Engines plus fuel for pilot training.

Back to engines....
BMW built the P&W Hornet single row radial engine under license and then proceeded to design the improved BMW132 engine. They should take it to the next level by building the P&W R-1830 twin radial under license.

Once BMW has experience with the P&W R-1830 clone they will build an improved twin radial that looks a lot like the P&W R-2000. This engine produces 1,300 hp while running on 87 octane fuel. Or maybe a bit more when equipped with a German supercharger and German fuel injection.

With generous funding and a bit of luck this BMW R-2000 engine will be in production by 1940. It's an ideal engine for small bombers like the Ju-87, Ju-88 and He-111.

The Fw-190 will be designed for this engine from the beginning (i.e. autumn 1937). Consequently it is 25% lighter then the historical Fw-190 and enters mass production before the end of 1940. The BMW R-2000 engine for this aircraft will get performance improvements similiar to the DB605 engine. MW-50, GM-1 and larger supercharger.

Meanwhile....
Germany makes a beeline for the DB603 and Jumo213 while continuing to improve the DB605 series. There is no development of larger piston engines like the Jumo 222 as they will be overtaken by jets and turbo props.

We still need more fuel!

[Shortround6]

[QUOTE=Burmese Bandit;585013]So: was there any HISTORICALLY PLAUSIBLE way for the Germans to have won, or at least fought to a draw, the aerial war in WW II ?

No. AS stated above it was a large part production. The US made over 100,000 fighters.
[QUOTE=Burmese Bandit;585013

And I say...

What about a TEN CYLINDER TWO ROW BMW SCALE UP OF THE 132???

First, let's look at history.

We know that the nine cylinder, air cooled, single row 132 was one of the most reliable engines of WWII, with over 20,000 produced. We know that it was designed in 1928 and first came into production in 1933.

Now I ask: what if in 1928 the engineers at BMW were just a little bit bolder, and designed not a single row nine cylinder radial, but a ten cylinder double row radial?.[/QUOTE]

They didn't "design" much of anything. They licenced the P&W Hornet engine.

IMHO the design work would have been just a little more complicated.

The engine would have suffered little or none of the cooling problems associated with double row radials, since the five cylinders in front would have had almost no obstructive effect on the five cylinders behind.

(For those on this forum who are not yet familiar with the design problems of air cooled radial engines, a brief explanation: All radial designs have to have an odd number of cylinders in each row. Thus the alternative to a ten cylinder two row engine would be a fourteen cylinder two row, or an even bigger eighteen cylinder two row engine. Once you get to fourteen cylinders the problem of engine overheating due to cooling air not reaching the rear cylinders starts to rear its ugly head, as indeed happened historically with the BMW 801. And of course if you go down the 18 cylinder route these problems increase.).

Two row engines have a few problems of their own. A longer, heavier crank case means the power to weight ratio isn't quite as good. THe extra length of the crankshaft also possed a few problems, high powered two row engines needed a middle bearing to avoid crankshaft delection. This ment a larger heavier crankcase. One extra cylinder was rarely thought to be worth it and there were several 10 cylinder 2 row engines made in the late 20s, early 30s.

So let's say that design-wise, a ten cylinder two row engine was perfectly plausible and possible in 1928-1933. So we get one more cylinder, and a 30 liter engine instead of the 27.7 historical BMW 132 engine in 1933. So we have 11% more displacement and 11% more power. So what?.

Well, see above. You could very well have more than 11% more weight.

While early Wright Cyclones did have some troubles as fighter engines they displaced 29.9 liters. Slightly large cylinders might have done as much as an extra cylinder and without the complications of the 2 throw crankshaft.

and especially for the JU 87, which was specifically designed to be draggy so that not too much speed would build up during a dive.

Against the slightly reduced power and the slightly increased drag would come the benefits of battle ruggedness, for unlike liquid cooled engines, air cooled radials could take hits knocking out one or two or sometimes even three cylinders and still survive. They would also be more reliable - which was, BTW, why the US Navy carrier aviation inisisted that all their planes be powered by air cooled radials .

Veiw over the nose might not be quite as good.

And the Ruggedness of the radial engine was not a given. Certain Radials other than the R-2800 showed a rather alarming tendency to stop running from rather minor damage.

So now, our BMW company builds the twin row 142 and its little brother, the single row 141 engine. How does this engine family hold up in the timeline of power requirements of the war?

Let's look at our historical comparision, the BMW 132. At its height the nine cylinder engine produced up to 1,200 hp. Extrapolating to an extra cylinder, this means our notional ten cylinder could have produced 1340 hp, and its little brother up to 670 hp. This means the engine is competitive to historical luftwaffe bomber engines up to 1944. The Ju 88 A-4 which was in widespread use used 1340 hp Jumo 211 engines. The Ju 87Stuka in its most developed version used 1400 hp Jumo engines. Our developed 142 could well have replaced the Jumo 211 in both these roles.

High powered 5 cylinder engines are not a really good idea. It was tried in the 20's and 30's with the Bristol Titan (5 Jupiter cylinders) and a French license/copy. Really big cylinders firing at widly spaced intervels give you an engine with sever vibration problems. THe 1200hp version of the BMW 132 was rather rare and used water injection to get that rating. Certainly do able but not an option that was well liked if there was an alternative.

BUT UNLIKE THE BMW 801 IT WOULD HAVE BEEN READY BY 1933 AND HAVE HAD THE LUXURY OF A LONG AND STEADY DEVELOPMENT PERIOD, SO THAT IT WOULD HAVE BEEN PRODUCING 920 HP BY 1937, 1000 HP BY 1939, 1100 HP BY 1940, 1200 HP BY 1941 AND 1350 HP BY 1942. THE BMW 801 WAS PRODUCING 1600 HP IN 1940, BUT TRUE MASS PRODUCTION DID NOT BEGIN UNTIL 1941.

IF THE NOTIONAL BANDIT 142 HAD BEEN PRODUCED INSTEAD, BY 1941 IT WOULD HAVE BEEN IN MASS PRODUCTION FOR FIVE YEARS ALREADY, AND PRODUCING 1200 HP WHICH WAS PERFECTLY ADEQUATE FOR TWIN ENGINE BOMBER DESIGNS AND STUKAS .

Not really. Torque is what turns propellers and there is no way a 30 liter engine produces as much torque as a 33 liter or larger engine. And if 1200 hp of highly stressed water injected engine was good enough why were Stukas fitted with 1400hp engines that didn't require water injection?


Could the Germans have benifited from a Radial engine other than the 801?

Yes but it wouldn't be from a 10 cylinder 30 liter one.

[tomo pauk]

Since Germans were producing Hornet under licence, the Twin Hornet/Twin 132 would be a feasible thing. The 2000HP mark would be well within sight.

Hmm ,perhaps they were trying this with 139 and failed..

[riacrato]

AFAIK the BMW 139 is essentially a two-row 132 (Hornet).

The result was an engine with serious overheating problems (worse than the initial BMW801). If anything another cylinder would make this even worse no?

[tomo pauk]

AFAIK the BMW 139 is essentially a two-row 132 (Hornet).

The result was an engine with serious overheating problems (worse than the initial BMW801).

So we agree on both accounts re. BMW139

If anything another cylinder would make this even worse no?

Methinks BBandit is contemplating the 10 cyl engine, not 2x10 one.

[davebender]

result was an engine with serious overheating problems

You avoid this by licensing the existing P&W 1830 engine design (first run in 1932). License the Wright R-2600 also if you can (first run in 1935).

If Germany acquires both radial engine designs they can entirely forego the expensive and time consuming process of creating a radial engines from scratch. If Germany acquires only the P&W 1830 they have a decent starting point for designing a larger twin radial engine.

[Shortround6]

You avoid this by licensing the existing P&W 1830 engine design (first run in 1932). License the Wright R-2600 also if you can (first run in 1935).

If Germany acquires both radial engine designs they can entirely forego the expensive and time consuming process of creating a radial engines from scratch. If Germany acquires only the P&W 1830 they have a decent starting point for designing a larger twin radial engine.

While licensing engines to Germany in the 1920's and very early 30's might have been OK I think the politcal climate might have changed a bit by 1936. The R-1830 might have been allowed in 1933-34. I doubt the R-2600 would have been in 1936-7. Peaple usually don't license prototype engines. They will license proven performers. The Boeing 314 Clipper may have been the first plane to fly with the R-2600.

P&W might have been able to offer the R-2180 (the first one, not to be confused with the post war engine) but since it went nowhere I am not sure what good it would do.

I am also not sure just how much a 1933-4 R-1830 would have really helped. It's not like the Germans couldn't have examined these engines by the dozen in 1939-40 if not before in comercial planes. I don't know the differences between the early engines and the latter ones but I think there quite a number. You can't just pour 100 octane fuel into an Early R-1830 and expect to get 1940-41 performance, at least not for more than a few minutes

[gorizont]

You avoid this by licensing the existing P&W 1830 engine design (first run in 1932). License the Wright R-2600 also if you can (first run in 1935).

If Germany acquires both radial engine designs they can entirely forego the expensive and time consuming process of creating a radial engines from scratch. If Germany acquires only the P&W 1830 they have a decent starting point for designing a larger twin radial engine.

For what sake?
Please, compare, for instance data of R2800 and Rolls-Royce Griffon.
And you'll see, that even with liquid coolant Griffon is easier on approximatly 100 kg, it's displacment less on 8,3 L, it's frontal area signifacantly less, and the power is equvalent.
Large-displacement inline air-engines to the middle of the war shows more potential and higher degree of technical sophistication and perfection.
The lucky times for large, two-row radials were only in the end 30' - beginning 40'.
Don't misunderstand me - I mean not the spreading of radials but the gap-time for development large inline engines -it took more time because of entirely new constructions of large inline engines. But for large radials there were cylinders, cylinder heads, push-roads etc from one-row radials, and time for their development took less time and the way of their construction was more evident (at 30') and easier.

[Shortround6]

For what sake?
Please, compare, for instance data of R2800 and Rolls-Royce Griffon.
And you'll see, that even with liquid coolant Griffon is easier on approximatly 100 kg, it's displacment less on 8,3 L, it's frontal area signifacantly less, and the power is equvalent.
Large-displacement inline air-engines to the middle of the war shows more potential and higher degree of technical sophistication and perfection.
The lucky times for large, two-row radials were only in the end 30' - beginning 40'.
Don't misunderstand me - I mean not the spreading of radials but the gap-time for development large inline engines -it took more time because of entirely new constructions of large inline engines. But for large radials there were cylinders, cylinder heads, push-roads etc from one-row radials, and time for their development took less time and the way of their construction was more evident (at 30') and easier.

But strangely enough it was only Large 2 row radial engines that dominated the commercial market from 1946 until the mid 50s with the commercial coming of the jet engine. Something to do with reliability, low operating costs, and time between overhauls

By the way the construction of inline V-12s was pretty much figured out in the 1920s with the Curtiss engines and the R-R Kestrel. Of course both companies were just stretching the V-8 Hispanos of WW I for the most part. Hispano themselves did an OK job of creating V-12s in the late 20's and early 30's considering the russian engines based off them were still in production shortly after WW II.

[tomo pauk]

When you mess with R-2800, you mess with me

On a more serous note, R-2800 managed to deliver 2000 HP in 1941, while Griffon could do that in 1943. In early 1945, R-2800 could deliver reliable 2800 HP, Griffonn: 2250.
When we calculate in the cooling system, weight difference is negligible. We could talk about drag, yet P-47M & -N were every bit as fast as anything powered by piston engine.
Then we could talk about resilience to battle damage, and radials come 1st there.
As for development speed and money invested, it was liquid-cooled/inline engines that were suffering big-time setbacks (Jumo-222 and a plethora of US engines - Chrysler and big Allisons for example).

[davebender]

Because RLM was determined to have a modern air cooled twin radial engine no matter what it cost to develop. There is really no other reason to explain why the Fw-190 wasn't powered by a liquid cooled V12 right from the beginning.