Replace Me-109 with Me-155?

[Shortround6]

Fellas,
What does "a slice in time" mean?
Thanks

To my way of thinking ( and they may disagree) it is the situation at a particular point in time. As in what engines were available in Aug of 1941 while disregarding what was available in either July or Sept.
While you don't want to compare engines that debuted several years apart "a slice in time" comparisons can also give a false picture if you are comparing the future potential of an engine near the end of it's development cycle and one near the beginning.

It has been said by people wiser than me that an engine goes through three stages.
1. It''s early stage, where it is low on power and teething troubles are being worked out so reliability is not all it could be. Users/customers are a bit unhappy but generally OK.

2. It's mid life where power is up and reliability is way up making for very happy users/customers.

3. near the end of it's life when it is being pushed to it's limits to remain competitive with newer designs. Power is even higher but the engine is temperamental and needs careful handling, reliability and durability are both going down hill and users/customers are increasingly starting to look elsewhere.

 

[Shortround6]

I don't know where to start: Did Germany even get the opportunity to have a detailed look at R2800s before 1942? Reverse engineering and industrialization in less than 2 years without detailed drawings, specifications? You'd take all these risks in 1942 Germany over developing satisfactory homegrown engines?

The first P-47s don't show up in England until Dec of 1942 and don't fly over Europe until March 10th 1943, a bit late to reverse engineer anything in time to do any good.
B-26s don't really show up until the North African invasion in Nov of 1942 and they have the older 1850hp "A" series engines.

Unless the Germans had somebody in the factory there was no way for them to get a detailed look at an R-2800 before 1942.

All the Jumo 213 needed was a better supercharger (which it got eventually, but too late) for pretty much the same result.

The Jumo 213 may have worked as an interceptor engine or short range bomber engine but it is highly suspect that it could do what the R-2800 did.

 

[michaelmaltby]

Cross section of time - frozen - and thus revealing the interaction of components within a system: engine, battle, economy etc.

MM

 

[DonL]

The Jumo 213 may have worked as an interceptor engine or short range bomber engine but it is highly suspect that it could do what the R-2800 did.

Please can you give some arguments or hints?

The Jumo 213 engines, had a very low specific fuel consumption. This was for cruising speed between 258 (190) to 274 (202) g/kWh (g/PSh) ) depending on the series.
And with the three gear two stage supercharger it was the only real high altitude engine from germany.

I can't see what the Jumo 213 can't do compare to the PR 2800.
In addition the Jumo 213J (2240 PS) with 4 Valves was developed and ready to go in production.

The dryweight of the the Jumo 213 E1 for B 87 fuel was 940kg.

The Ta 152 H1 with something about 1050 l complete internal capacity for fuel, MW 50 and GM 1, so I think something about 800-900l internal fuel had a range of 1550 km.
So the Jumo 213 wasn't a short legged engine with too much fuel consumption.

 

[riacrato]

The first P-47s don't show up in England until Dec of 1942 and don't fly over Europe until March 10th 1943, a bit late to reverse engineer anything in time to do any good.
B-26s don't really show up until the North African invasion in Nov of 1942 and they have the older 1850hp "A" series engines.

Unless the Germans had somebody in the factory there was no way for them to get a detailed look at an R-2800 before 1942.

At first I thought davparl suggested captured examples from Soviet Union, but I guess he meant Russian reverse engineerng as a term. Now I know that P-47s were delivered to the VSS and I assume some spare engines as well. But I don't know when and I don't know if anyhting was ever captured to make the story possible.

The Jumo 213 may have worked as an interceptor engine or short range bomber engine but it is highly suspect that it could do what the R-2800 did.

What DonL said. The Jumo 213 was seen as the ultimate clean copy 211 and as such I'd be very surprised if there was anything the 211 could do that the 213 could not. It had a fuel efficiency good enough for it to be used as a bomber or nightfighter engine (Ju 188 and Ju 388). So what can the R2800 do what the Jumo 213 could not in your opinion? The obvious air-cooled vs liquid-cooled arguments aside.

 

[davebender]

should have pulled a Russian reverse engineering on a captured R-2800.

I'll buy that. The problem is obtaining a R-2800 early enough to matter. By April 1939 BMW had an 801 prototype running. I suspect BMW promised a lot more then 1,539 hp and a relatively short development period.

 

[DonL]

It had a fuel efficiency good enough for it to be used as a bomber or nightfighter engine

It had the best fuel efficiency from all german engines. This was stated in many books.

Also I don't see were the Ta 152H1 was an interceptor. The range was 1550km with internal fuel.
Please name any other high performance fighter year 1944/45 with this range with internal fuel, accept the Mustang. The Ta 152H1 played in the same league with a Jumo 213 E1 engine with B 87 fuel not C3 fuel.

 

[Shortround6]

Please can you give some arguments or hints?

The Jumo 213 engines, had a very low specific fuel consumption. This was for cruising speed between 258 (190) to 274 (202) g/kWh (g/PSh) ) depending on the series.
And with the three gear two stage supercharger it was the only real high altitude engine from germany.

R-2800s could get specific consumptions down around .45lbs/hp/hr or 204 g/hp/hr so the difference isn't in fuel consumption.
The difference is in the life of the engines. The R-2800 was good for hundreds of hours before overhaul and in post war service went to 2000 hours recommended between overhauls with a few engines making 3000 hrs. Granted this wasn't combat but what was the recommended overhaul life of a 213?
How many long range/ long duration missions were you going to get before pulling the engines? The US and British sometimes figured on needing 50% more engines (of all types) than a strict count of engines to airframes would cover and that does not include normal spare parts. The US got themselves in trouble when they only ordered 20% extra Merlin engines for the P-40F Ls. The British gave the US up to 600 Merlin engines to swap into P-40s in the field and/or to break down for parts while the US came up with a program to re-engine the planes with Allisons.
I have seen figures as low as 50 hrs thrown around for overhauls times for Jumo 213s but I don't know if that is true. I would venture to guess however that the over haul life of the 213 was lower than the R-2800 due to the higher rpm and piston speed. While you may get a fair number of flights out of an interceptor or short range bomber (1 1/2-4 hours of flight goes into overhaul life how many times?) trying to use the same engine for long range recon or bombing gets a little expensive in terms of spare engines needed and overhaul/maintenance facilities and manpower.

I can't see what the Jumo 213 can't do compare to the PR 2800.
In addition the Jumo 213J (2240 PS) with 4 Valves was developed and ready to go in production.

The dryweight of the the Jumo 213 E1 for B 87 fuel was 940kg.

The Ta 152 H1 with something about 1050 l complete internal capacity for fuel, MW 50 and GM 1, so I think something about 800-900l internal fuel had a range of 1550 km.
So the Jumo 213 wasn't a short legged engine with too much fuel consumption.

On a flight by flight basis maybe the Jumo 213 could match the R-2800 but as an engine to be used in many different aircraft flying many different roles it may have presented too many maintenance issues to be really good at all the roles.
Using a hot rodded 35 liter engine at 3700rpm probably wasn't the way to go. I would like to see the specific fuel consumption figures on that engine, especially at altitude.

 

[DonL]

Using a hot rodded 35 liter engine at 3700rpm probably wasn't the way to go

It was 3200rpm for continuous operation and not 3700rpm.
The Jumo 213 was in combat and mass produced since 1942 and I haven't read about serious problems.
The three gear two stage supercharger had some problems at the beginnings but not the engine itself.

In addition the USA had completly other opportunities to manufactor matalurgie and raw materials, you should not forget these when you compare.

And the Jumo 213 was the planed engine for whole lot of german aircrafts in very different roles.
Look at the Ju 88 G6 and other aircrafts.

The DB 603 and the Jumo 213 were constructed as quick change engines. So every Jumo 213 could be replaced with an DB 603 and the other way around

 

[davebender]

On the other hand most fighter aircraft built for this monster engine were large and heavy. Plus you have a huge frontal area of 15 sq ft (compared to 6.3 sq ft for the Ju213A engine). Consequently the P-47D15 was a fuel hog that achieved long range only by carrying an incredible 375 gallons of internal fuel. 4 Me-109s (or Me-155s) could be fueled with the contents from a single P-47. Perhaps WWII Germany could have built a more fuel efficient fighter aircraft powered by the R2800 engine. They certainly didn't have enough aviation gasoline to operate P-47s.

Internal Fuel Capacity. For comparison purposes.
Me-109G10. 90 gallons. (340 liters)
Fw-190A8. 141 gallons. (535 liters)

 

[Shortround6]

It was 3200rpm for continuous operation and not 3700rpm.

And the R-2800 ran at 2550-2600 for continuous operation and not the 2700-2800rpm used for take off and max power. Cruising rpm was 2250 or below.
The 213 B,C and E maxed at 3200rpm but then they also maxed at 1750hp for take off.
The F did do better but the J which every on likes to quote the power number from was the one at 3700rpm.
It's cruise rating was 1970hp, was that at 3200rpm?
Late model P-47s could run 1700hp at 2600rpm up to 25,000-26,600ft continuous.

The Jumo 213 was in combat and mass produced since 1942 and I haven't read about serious problems.

Care to give information about being combat in 1942?
or do you mean sometime in 1943?

In addition the USA had completly other opportunities to manufactor matalurgie and raw materials, you should not forget these when you compare.

Not forgetting, the Jumo 213 might have been even better with better materials but that is really getting into "what if" land. maybe a German built R-2800 in WW II would have had a shorter overhaul life due to poorer materials too but there were certain choices made in it's design that were going to affect it's durability. that choice being the high rpm and high piston speed. There are reasons no other aircraft engine maker used pistons speeds that high.

And the Jumo 213 was the planed engine for whole lot of german aircrafts in very different roles.
Look at the Ju 88 G6 and other aircrafts.

What choice did they have?
They had to use what they had, not what they wished they had. If it is a choice between using a short lived engine in a certain role and not having an aircraft that can fly that mission at all you use the short life engine. Just because they used it doesn't mean it was the best for the role or that it didn't place a strain on the maintenance services that that other countries didn't have to put up with.
Not that other countries didn't have problems of their own.
Parachuting the plans and a sample engine of either an early R-3350 or Napair Sabre into Germany in 1941 might have done more damage to the German aircraft industry than a 1000 bomber raid

The DB 603 and the Jumo 213 were constructed as quick change engines. So every Jumo 213 could be replaced with an DB 603 and the other way around

So what?

If you have to swap engines every 10-15 missions to send them back for overhaul it doesn't really matter if you can swap them 3 or 4 times quicker than the allied plane that gets it's engines pulled after 30-45 missions of the same length. You have the same number of man hours at the squadron level and a whole bunch more hours at the overhaul depot.
It is an advantage to keeping planes flying if your transport network is screwed up so you can't get the right engines to the right units but it no real substitute for longer lasting engines in the first place is it?

 

[Shortround6]

On the other hand most fighter aircraft built for this monster engine were large and heavy. Plus you have a huge frontal area of 15 sq ft (compared to 6.3 sq ft for the Ju213A engine).

When you get the frontal area of the pilot/cockpit down to to 6.3 sq ft or less let me know.

Consequently the P-47D15 was a fuel hog that achieved long range only by carrying an incredible 375 gallons of internal fuel. 4 Me-109s (or Me-155s) could be fueled with the contents from a single P-47. Perhaps WWII Germany could have built a more fuel efficient fighter aircraft powered by the R2800 engine. They certainly didn't have enough aviation gasoline to operate P-47s.

Internal Fuel Capacity. For comparison purposes.
Me-109G10. 90 gallons. (340 liters)
Fw-190A8. 141 gallons. (535 liters)

First, learn the difference between Imperial gallons and US gallons.
Then learn which planes used which measure.
Then do the math.

For comparison
Early P-47. 305 US gallons (1,154.6 liters)
Later P-47D. 375 US gallons (1,419.5 liters)

Didn't the 109 use a 400 liter internal tank?
And the FW was 599liters if the rear tank was used for fuel and not MW 50.

Maybe it doesn't change things a lot but lets be accurate.
As far as the range bit goes that early P-47 was supposed to be able to go 450 miles at 30,000ft at 370mph on the 265 US gallons of fuel.

A Bf 109G-6 was supposed to go 350 miles at 330 mph at 19,030 ft on internal fuel. If you have figures for the G-10 bring them on out.

I wonder what the range of the P-47 would be if slowed down to 330-340mph?
Maybe 550miles on that 265 US gallons?

Yes the 109 is getting better fuel mileage but much closer to twice the P-47 than 4 times and of course it is carrying a much smaller weight of guns and ammo.

 

[tomo pauk]

On the other hand most fighter aircraft built for this monster engine were large and heavy. Plus you have a huge frontal area of 15 sq ft (compared to 6.3 sq ft for the Ju213A engine). Consequently the P-47D15 was a fuel hog that achieved long range only by carrying an incredible 375 gallons of internal fuel. 4 Me-109s (or Me-155s) could be fueled with the contents from a single P-47. Perhaps WWII Germany could have built a more fuel efficient fighter aircraft powered by the R2800 engine. They certainly didn't have enough aviation gasoline to operate P-47s.

Internal Fuel Capacity. For comparison purposes.
Me-109G10. 90 gallons. (340 liters)
Fw-190A8. 141 gallons. (535 liters)

1st, R-2800 was not a monster engine - it was under 1000 kg dry, while providing 300 HP more than similarly sized BMW 801, or Jumo 213. And it was available 1/3rd of German WW2 earlier then 213.
2nd, when comparing frontal areas of radial vs. inline, it would be good to add the radiator area for the later.
3rd, when comparing ranges, stating miles flown vs. fuel carried would be nice.
4th, also, picking the heaviest fighter with R-2800 vs. the light opposition, for combat range comparison is, well, silly. Perhaps we could add F-4U1 in comparison, with twice the range vs. 109 190, on 234 gallons of internal fuel?

 

[riacrato]

How about we stop dabbeling about a German R-2800. Really it's just all opinion and what if's and had not's. It's not going to happen one way or another. The R-2800 was a great engine, possibly the best radial of the war. But it's an American engine and aircraft design is no cherry picking, you work with what you got. Let's keep it at that.

Your opinion is that the Jumo 213 was for some reason not usable in the same roles as the R-2800. For me this goes completely against the facts of its development and application as an allround engine for many different projects including btw the long range recon role you just mentioned. If you have any source indicating it was meant to be an interceptor engine please post so. I'm sure if there was such a drastic limitation for the planned purposes of this engine there would be a primary source for that. What alternatives did they have? DB 603. Was there ever a distinction made between the DB 603 with its normal rpm and Jumo 213 with its high rpm regarding feasible applications? No. If you have sources indicating catastrophic problems related to rpm, again, I'd be very interested to see them.

As for specific fuel consumption. When DonL says it had the lowest sfc of any German engine you counter this by saying the R-2800 could go even lower. So what? The point is unless you count all German engines or all engines with a sfc worse than 260 kg/kwh as "interceptor engines" your conclusion should be that this is no indication whatsoever that the Jumo 213 is one.

As for overhaul times: Which MTBO of a German 1944-45 engine was not poor? It plagued pretty much all of them and we all know the reasons. To take this is an indication of the intended purpose as an interceptor engine is misleading imo. Unless you have real figures and strong evidence that the MTBO was NOT for the same reasons poor as that of the DB 603, late DB 605s...

The Jumo 213 was a development of the Jumo 211 with no specific target in mind and certainly not the Ta 152 which was barely on paper when the engine made its first test runs. It was a late-war allround engine with an unsually high rpm, end of story. And I think it's useless to quote performance figures of inlines side by side with that of radials without taking the aerodynamic deficiencies of the latter into context. The Merlin, Jumo and Daimler powered fighters certainly did okay when compared to its radial-powered contemporaries, pure horsepowers aside.

 

[NZTyphoon]

Just for comparison:
Napier Sabre IIA or IIB (from the Tempest V Pilot's Notes 1944):
Take-off to 1,000 ft = 3,700 rpm
Climbing (1 hr limit) = 3,500 rpm (or 3,700 rpm for Sabres embodying Mod. 158 or 297 and Mod. 276 ie: Sabre IIB)
Rich Continuous = 3,150 rpm
Weak Continuous = 3,150 rpm
Combat 5 mins = 3,700 rpm

(Lumsden 2003)
Displacement = 2,240 in³ (36.65 L)
Dry weight = 2,260 lb (1,024 kg)
Power = 2,235 or 2,400 hp (IIA or IIB)

(Pilot's Notes)
Fuel Consumption: ( imp. gallons per hour)
Weak mixture M ratio at 5,000 ft
100 g/ph at 3,150 rpm +6 lb/sq.in boost
42 g/ph at 2,300 rpm -4 lb/sq.in boost

Weak mixture S ratio at 20,000 ft
94 g/ph at 3,150 rpm 0 lb/sq.in boost
49 g/ph at 2,300 rpm -4 lb/sq.in boost

Rich Mixture at all altitudes:
190 g/ph at 3,700 rpm +7 lb/sq.in boost
132 g/ph at 3,150 rpm +4.5lb/sq.in boost

Rolls-Royce Griffon III or IV (Spitfire XII Pilot's Notes 1943)
Take-off to 1,000 ft = 2,750 rpm
Climbing (1 hr limit) = 2,600 rpm
Rich Continuous = 2,400 rpm
Weak Continuous = 2,400 rpm
Combat 5 mins = 2,750 rpm
(Lumsden 2003)
Displacement = 2,240 in³ (36.65 L)
Dry weight = 1,820 lb (825 kg)
Power =1,850 hp

(Pilot's Notes)
Fuel Consumption: ( imp. gallons per hour)
Weak mixture M ratio at 5,000 ft
74 g/ph at 2,400 rpm +6 lb/sq.in boost
42 g/ph at 2,000 rpm -4 lb/sq.in boost

Weak mixture S ratio at 20,000 ft
75 g/ph at 2,400 rpm +6 lb/sq.in boost
43 g/ph at 2,000 rpm -4 lb/sq.in boost

Rich Mixture all altitudes
132 g/ph at 2,750rpm +12lb/sq.in boost
88 g/ph at 2,400 rpm +7lb/sq.in boost

 

[davebender]

I agree. Which is why I like the Me-155 option.

By 1943 Germany was producing DB605 engines like they were hot rolls. Most teething problems were fixed and significantly more powerful versions of the engine were not far off. The Me-109 airframe was also being produced in large numbers and at a very low cost compared to most contemporary fighter aircraft. Switching to the Me-155 shouldn't be terribly difficult as we are essentially just giving the Me-109G a new wing with wide track landing gear and room for internal MG151/20 cannon. The resulting aircraft won't be quite as capable as a Fw-190C or Fw-190D but it's good enough and can be produced in large numbers.

 

[DonL]

Parachuting the plans and a sample engine of either an early R-3350 or Napair Sabre into Germany in 1941 might have done more damage to the German aircraft industry than a 1000 bomber raid

Sorry but you have no expert knowledge about german engine technology of WW II!
This statement shows your ignorance!

Jumo 222
BMW 802
BMW 803

Jumo 222 A/B-1 2000 PS at 3200rpm with 43.380 cm³, was in the air
Jumo 222 A/B-2 2500 PS at 2900rpm with 49.880 cm³ was in the air
Jumo 222 C/D 3.000 PS at 3200rpm with 55.480 cm³ testengines were running!

You should rethink your post and statement. And the Jumo 222 was production ready and in development since 1937. So I don't know what is your intention but german aircraft technology of WWII didn't lag on aircraft designs or engine designs, it laged on enough metallurgy, raw materials and enough C3 fuel thats all!
There was no technology advantage of the USA or England!

And besides the Lancaster Bomber was powered by an inline rolls royce merlin and no radial engine. And the Jumo 213 could match with a rolls royce merlin.

 

[DonL]

Not forgetting, the Jumo 213 might have been even better with better materials but that is really getting into "what if" land. maybe a German built R-2800 in WW II would have had a shorter overhaul life due to poorer materials too but there were certain choices made in it's design that were going to affect it's durability. that choice being the high rpm and high piston speed. There are reasons no other aircraft engine maker used pistons speeds that high

Lol, look at ricartos reply! You suggestive something that you can't proof! The lag of raw materials and metallurgy by german aircarft industry of WWII is proofed! The Jumo 213, 211, 601 and 603 had no serious engine problems!
The only one was the DB 605 and all were solved at the begining of 1944 for DB 605 A, AS and D

What choice did they have?
They had to use what they had, not what they wished they had. If it is a choice between using a short lived engine in a certain role and not having an aircraft that can fly that mission at all you use the short life engine. Just because they used it doesn't mean it was the best for the role or that it didn't place a strain on the maintenance services that that other countries didn't have to put up with.

Have you any sources or evidences for a short life Jumo 213?
The normal life of a Jumo 211F was 200 hours! Thats what is my knowledge to the Jumo 213!
And this 200 hours were dued to the metallurgy and not the design!
So you can report or tell a book of storys about the running hours of allied engines that isn't any real hint at all of a what if superior design!

 

[Shortround6]

How about we stop dabbeling about a German R-2800. Really it's just all opinion and what if's and had not's. It's not going to happen one way or another. The R-2800 was a great engine, possibly the best radial of the war. But it's an American engine and aircraft design is no cherry picking, you work with what you got. Let's keep it at that.

leaving out a German R-2800 is fine with me.

"you work with what you got"
is rather the whole point here isn't it?

the Germans had the Jumo 213 and they had the DB 603 and the had the BMW 801 at a bit less power and that is ALL they had. The 605 was bit small by the end of the war unless it was really pressed.

Your opinion is that the Jumo 213 was for some reason not usable in the same roles as the R-2800. For me this goes completely against the facts of its development and application as an allround engine for many different projects including btw the long range recon role you just mentioned.

"you work with what you got"

If you have any source indicating it was meant to be an interceptor engine please post so. I'm sure if there was such a drastic limitation for the planned purposes of this engine there would be a primary source for that. What alternative's did they have? DB 603. Was there ever a distinction in class made between the DB 603 with its normal rpm and Jumo 213? No. If you have sources indicating catastrophic problems related to rpm, again, I'd be very interested to see them.

There is no primary source for it. It is just logic. In German's situation from 1942 onward a high powered engine with a short overhaul life is not a big handicap IF it is used for interceptors or short ranged aircraft. I have no information on catastrophic problems and never said I did. I have been referring all along to service life or overhaul life which is somewhat different isn't it?

The Problem isn't so much RPM as it is piston speed and here the DB 603 was no great shakes either. With it's long stroke and "normal" rpm it had a piston speed of 3190.5 fpm at 2700rpm. The Jumo 213 was either 3520fpm or 4008fpm depending on 3250 rpm or 3700rpm.

For comparison piston speeds for a few other engines are:

R-2800 at 2800rpm.----2800fpm
Merlin at 3000rpm-------3000fpm
Sabre at 3,850rpm------3048fpm
Griffon at 2750rpm------3025fpm
DB 605 at 2800rpm-----2940fpm
Hercules at 2800rpm----3030fpm
Centaurus at 2700rpm--3150fpm
M-105 at 2700rpm-------3100fpm
AM-38 at 2350rpm-------3035fpm

And for a little perspective
1939 auto union Grand Prix V-12 at 7000rpm------3445fpm
1939 Mercedes Grand Prix V-12 at 7500rpm-------3445fpm
1951 BRM Grand Prix V-16 at 11000rpm------------3486fpm
1955 Mercedes Grand Prix I-8 at 8500rpm---------3837fpm

these are straight piston speeds and uncorrected for the Bore:stroke ratio. Some racing engines in the early 50s did go over 4000fpm.
Pardon me if I think that airplane engines that use Grand Prix piston speeds may not have been the best idea. But "you work with what you got".

As for specific fuel consumption. When DonL says it had the lowest sfc of any German engine you counter this by saying the R-2800 could go even lower. So what?

You are right, so what, I am not the one who brought specific fuel consumption into the discussion.

As for overhaul times: Which MTBO of a German 1944-45 engine was not poor? We all know the reasons and we all know the reasons for it. To say this is an indication of its intended purpose is misleading imo.

"you work with what you got"
Then don't say a Jumo 213 with a better supercharger could do what an R-2800 could do.
I didn't say that it was it's intended purpose, I have been saying that for certain jobs, like interceptor the difference in overhaul times wouldn't make that much difference. For long range or long duration flights it would and more from an operational point of view than form a specific, one mission point of view.

And I think it's useless to quote performance figures of inlines side by side with that of radials without taking the aerodynamic deficiencies of the latter into context. The Merlin, Jumo and Daimler powered fighters certainly did okay when compared to its radial-powered contemporaries, pure horsepowers aside.

An interesting comparison can be made between the Merlin and the R-2800 because both were installed in the same airframe. Granted it was a 4 engined airliner and it was post war but more than one was built of each type and they were flown for a number of years. the Merlin looses this contest but at the time R-2800s had to bought with cash from out side the commonwealth while Merlins were from within the commonwealth.

"you work with what you got"

 

[Shortround6]

Me "Parachuting the plans and a sample engine of either an early R-3350 or Napair Sabre into Germany in 1941 might have done more damage to the German aircraft industry than a 1000 bomber raid"

Sorry but you have no expert knowledge about german engine technology of WW II!
This statement shows your ignorance!

Please, get a grip, it was joke. Read it again. Both the early R-3350 and the Napair Sabre looked good to begin with but with hindsight were both problematic engines that took a great deal of time, money and effort to bring to anything approaching a satisfactory service engine. And that is with the better materials of the allies. An argument could be made that the Allies would have been better off junking both of them and concentrating on other engines.

How you took this to be a slam against the German aircraft industry I don't know. It was a way of saying that the Allies produced some real mistakes of their own.

Now can we all say "Rolls-Royce Vulture" or Continental IV-1430 or Lycoming O-1230/H-2470 for some even bigger ones.

So I don't know what is your intention but german aircraft technology of WWII didn't lag on aircraft designs or engine designs, it laged on enough metallurgy, raw materials and enough C3 fuel thats all!
There was no technology advantage of the USA or England!

Actually there was an advantage in Allied technology but it wasn't so much in the design of the engines but in how they were made.
I have read one account of how the Germans were amazed at the forged cylinder heads on some of the American radials, not so much that they were forged but at the idea that the Americans could produce thousands of such forgings a week. Some of these things meant that the engine designers could pursue paths the German designers could not. It is no good coming up with a trick design if it can't be massed produced.
The Americans came up with several ways to increase the cooling on radial engines. One was the aluminium "muff" that fit over the steel barrel. The aluminium fins were larger and cooled better than steel fins, this idea goes back to WW I but the ability to make the steel liner and the aluminium stay together with temperature changes took a bit longer to work out as did machining the fin fins. Wright did come up with rolling and caulking sheet metal fins into groves cut in the outer cylinder walls instead of machining the fins out of the steel of the cylinder walls. maybe somebody else had the Idea originally but the US had the ability to make such cylinders in quantity and that opened up a path for the designers. It was this sheet metal finning that helped allow the R-1820 to go over 1200hp and the R-2600 to go from 1700hp to 1900 hp.
Going back to Wright and the R-3350, it took them way too long to get over the "not invented here" and adopt the type of bearings (silver) that P&W had been using for several years even when it was offered to them at no cost. To turn an early R-3350 into a late R-3350 you needed the better bearing material, you needed the sheet metal cylinder finning, you needed to change from cast heads to forged heads and a bunch more.
Please note that none of this has to do with cylinder layout, or valve timing or valve angle or intake manifold design or carburetors or fuel injection or a host of other things that may be considered engine design.