Which country designed the best engines for WWII?

[davparlr]

Originally Posted by DerAdlerIstGelandet

Hmm I cant really vote for anyone, its a tough call.

Best Radials in my opinion were built by the US with the PW series and followed by Germany with the BMW 800s.

Inlines is a toss up between German and England in my opinion.

I agree. American radials were very impressive in performance and growth and carried on for many years after the war when liquid cooled engines faded out.

I just could not determine best in inline. Both the Merlin and DB 601 were terrific engines, and, if interchanged, would not make a blip on the war.

Jet engines, Germany.

Originally Posted by renrich

What hurts US is no really successful inline engines. Had to use RR in fighters and PT boats.

PT boats were powered by Packard Marine engines derived from the Liberty engine

From 'http://www.ptboats.org/20-01-05-ptboat-008.html'

PACKARD V-12 MARINE ENGINE

The Packard 4M-2500 engine was utilized in all U.S. Navy World War II PT boats. This engine was based on the 1925 Liberty aircraft engine which was earlier converted for marine use in racing boats. During the war the Packard engine went through various performance updates and modifications. With early engines rated at 1100 h.p. and progressing to 1500 h.p. during the war. The Packard 4M-2500 engine was a supercharged, water cooled, gasoline powered V-12 engine, weighing approximately 2900 pounds.

The Packard 4M-2500 marine engine was not the Rolls-Royce Merlin, nor did U.S. Navy PT boats use the R.R. Merlin engines, which is sometimes misstated. However, Packard did built a version of Merlin Engine under contract by Britain for British aircraft use

[eddie_brunette]

I voted for Germany. England made great inline, USA made great radial, Germany made both

....and BMW recently won a F1 race....but that just off topic

[red admiral]

We're at cross purposes in referring to max economical sfc and that at full power. Its no surprise that the Merlin's fuel consumption was poor when running at full power as the engine ran rich to suppress detonation. The Germans got around this in one way by adopting MW system which cooled the charge. The figure of 0.42 was for a Merlin X at 2280rpm, other conditions not given. Its strange that aircraft don't cruise on maximum power. Typical mission profile was for 10 minutes combat - 20% = fuel left for cruising

I think I'm going to trust a RR report rather than some obscure German one with regards to Merlin weights. Maybe I'll just pop over to Derby and weigh one of things, its not far.

The Metrovick F.2/4 Beryl is not the same as the F.2. It was a larger service engine for the SRA.1 with a zero stage added to pass more airflow. The F.2 ran in 1941, passed its tests in 1942 and went up to 2500lbf in 1943. The flight test program ran for 210hours. Also developed were the F.3 and F.5 turbofan and UDF respectively, using the F.2 as a gas generator. The F.3 developed 3900lbf on initial tests in 1943, rising to 4600lbf. The F.5 ran a bit later and gave 4710lbf. Fuel consumption was 40% less than anything else running at 0.66lb/lbf-hr

[Kurfürst]

Originally Posted by red admiral

We're at cross purposes in referring to max economical sfc and that at full power. Its no surprise that the Merlin's fuel consumption was poor when running at full power as the engine ran rich to suppress detonation. The Germans got around this in one way by adopting MW system which cooled the charge. The figure of 0.42 was for a Merlin X at 2280rpm, other conditions not given.

Its a pity isn`t it. Is it for shaft horsepower or considered for full horsepower ratings? And, sfc varies considerably with altitude.

Right now it appears to me you were comparing apples and oranges; and early, single stage Merlin at economic cruise settings to a later high altitude DB engine at high power.

In other words, best conditions for the R-R engine and worst possible conditions for the DB engine.

One curious thing though; early Spitfires were blessed with a somewhat greater (economic) range than early 109; undoubtedly, the early, moderately boosted and supercharged, single stage Merlin had good fuel economy.

The later Spitfires however, despite having increased their fuel capacity by 50%, had only 2/3s the range compared to the early Spitfires; the fuel capacity of later 109s remained unchanged, but their range increased by 50%.

Its certainly not that the Merlin had poor fuel economy to start with; it become such an engine due to its way of development (insufficent displacement, high RPMs, high supercharging needs, low CR) over time.

Originally Posted by red admiral

I think I'm going to trust a RR report rather than some obscure German one with regards to Merlin weights.

Well we certainly have a German report with rather precise measurements; as a matter of fact, it is the most detailed report on the Merlin 61 and its aux. systems I have seen so far; the suggestion that Germans were inapt at measuring the weight of an engine has considerable merit in the field of bizarre humor IMHO.

On the other hand, we have your word that there`s a RR report in existance, and that it says what you tell to us. Normally that would suffice, but I`ve just asked you a direct question, wheter your earlier statements were the same as told in this RR report, and you didn`t answer that question so far.

I`d like to see the source wheter it makes the same claims as you do. Reminder, you claimed that

'Merlin 61 weight of 1640lb includes two stage supercharger, intercooler and carbs.'

So, taking it with a grain of salt appears to be the reasonable procedure.

Post the report to support your position, please.

Maybe I'll just pop over to Derby and weigh one of things, its not far.

That sounds a good solution too. Maybe you are more adept at this than German intelligence teams in the 1940.

The Metrovick F.2/4 Beryl is not the same as the F.2. It was a larger service engine for the SRA.1 with a zero stage added to pass more airflow.

Yup, we are on common ground now.

The F.2 ran in 1941, passed its tests in 1942 and went up to 2500lbf in 1943. The flight test program ran for 210hours.

Now, can you shed more information on the matter as to how far these projects went towards completion.

What does that mean, 'went up to 2500lbf in 1943' - run on a bench at such thrust under laboratory conditions for 5 minutes?

Surely you do not want to compare that to service ratings of other jet units, do you?

Also developed were the F.3 and F.5 turbofan and UDF respectively, using the F.2 as a gas generator. The F.3 developed 3900lbf on initial tests in 1943, rising to 4600lbf. The F.5 ran a bit later and gave 4710lbf. Fuel consumption was 40% less than anything else running at 0.66lb/lbf-hr

These sound very ambitious projects. Do you know how far these were from being production and service-ready?

[red admiral]

Ratings for the F.2 were service ratings, 1800lbf initially and then 2500lbf.

The F.3 aft fan unit was ready in 1943. With gearing up to production you're talking 1944 sometime. It could also be fitted to other jet engines to give a similar increase in thrust. It was not adopted because it would have caused too many problems if an example fell into German hands. Simple to copy and then bolt on to the rear of existing engines to give much improved performance. The remaining example is on display at RRHT Derby in the main hall.

I don't have a great deal of information on the F.5, but it was a bit later. It shouldn't be too difficult to adopt as per the F.3. The remaining unit is on display up at Manchester but I haven't been there for years. There may be more information there.

[Juha]

Kurfürst
I'm still rather convinced that the engine weight in P-51B/C weights table incl. the 2nd stage of supercharger and intercooler, because I'm sure that the empty and basic weights of P-51B/C incl. them and of course also the carbs. I checked the table adding all subweights and all added up to given empty and basic weights. But let's agree to disagree with that.

"The later Spitfires however, despite having increased their fuel capacity by 50%, had only 2/3s the range compared to the early Spitfires."

What's your source of that? Because for ex. Morgan's and Shacklady's Spitfire The History gives clearly greater range to Mk VII and VIII than to Mk I and Mk V. And Mks VII and VIII were the fighter types which had almost 50% more fuel than the early types.

Juha

[Kurfürst]

Originally Posted by Juha

I'm still rather convinced that the engine weight in P-51B/C weights table incl. the 2nd stage of supercharger and intercooler, because I'm sure that the empty and basic weights of P-51B/C incl. them and of course also the carbs. I checked the table adding all subweights and all added up to given empty and basic weights. But let's agree to disagree with that.

Well why not disagree. Still, the original point stands - the Merlin, with all its neccessary accessories (ie. as a powerplant, complete with cooling, and aux. devices like superchargers, intercoolers etc. rather than a bare engine) was a heavier one than the contemporary DBs.

If you recall the original point was the wheter the Merlin`s small displacement vs. power makes it impressive. I think its fairly well shown it isn`t, quite to the contrary, its small displacement was a liability that didn`t bring any advantages, but a lot of disadvantages (at least from the practical standpoint, ie. level of suitability as a fighter powerplant. As an engineering feat, its a wonderful engine).

Originally Posted by Juha

"The later Spitfires however, despite having increased their fuel capacity by 50%, had only 2/3s the range compared to the early Spitfires."

What's your source of that? Because for ex. Morgan's and Shacklady's Spitfire The History gives clearly greater range to Mk VII and VIII than to Mk I and Mk V. And Mks VII and VIII were the fighter types which had almost 50% more fuel than the early types.

Juha

Spitfire datasheets. Cross check for example the Spit I - V and IX, ll of these had 85 gallon internal. The ranges keep decreasing.

Ie. 85-gallon inter fuel Marks
Mk I. 595 miles @ 185 mph
Mk VB 480 miles @ 185 mph
Mk IXF 434 miles @ 220 mph

The VIII of course had more range, but that`s hardly surprising, given that it also increased fuel capacity by 50%. Still its range is only 25% greater than the Mk I...

Then compare the VIII and XIV. Same amount of fuel carried (120 gallons). Range goes down from 740 to 450 miles... on the same fuel the Griffon must have been a real fuel hog.

[Juha]

Kurfürst,
I would not say that the engine which powered P-51 B/C and D/K or Spitfire I, II and from Mk VII onwards had lot of disadvantages as a fighter powerplant. Or then German airframes had something wrong on them. Otherwise it is difficult to explain why LW had so much trouble with abovementioned a/c. And those single-stage Merlins were good for fighter bombers, for ex. XXV/25, 658 kg 1480/1640 hp, used for ex. in Mosquito FB VI.

Quote: “Spitfire datasheets. Cross check for example the Spit I - V and IX, ll of these had 85 gallon internal. The ranges keep decreasing.

Ie. 85-gallon inter fuel Marks
Mk I. 595 miles @ 185 mph
Mk VB 480 miles @ 185 mph
Mk IXF 434 miles @ 220 mph

The VIII of course had more range, but that`s hardly surprising, given that it also increased fuel capacity by 50%. Still its range is only 25% greater than the Mk I...

Then compare the VIII and XIV. Same amount of fuel carried (120 gallons). Range goes down from 740 to 450 miles... on the same fuel the Griffon must have been a real fuel hog.”

That’s the info I also have. Yes, Griffon was thirstier than Merlin but Griffon had not much common with Merlin but the manufacture. And yes, also in Merlins fuel efficiency suffered from Mk I to Mks VII/VIII, 43% more fuel produced only 24% more range. Already Mk Vb had worse fuel efficiency than 109Gs in FAF service. But still Mk VIII had clearly better range than the FAF 109G-2/-6 with internal fuel only (740mls vs 750km or 660 mls vs 750 km depending what range one takes for Mk VIII).

Juha

[Glider]

Kurfurst.
The weight of the MW50 on the 109 has always been a bit of a mystery to me and its one I have asked before.
I know the full weight of the MW50 on a Ju88S was a substantial 1,300lb. Clearly the 109 installation is going to weigh a lot less but to get it down to 87kg is a massive drop, is there a breakdown or source that I can compare it with. Any comments appreciated

The source for the 1,300lb is Janes Fighting Aircraft page 297.

[Juha]

Glider
the weight of MW50 system in Bf 109G was appr. 100 kg. At least it and GM-1 system increased the weight of a/c 100 kg according to a Handbook. IIRC that was the Handbook of 109G-6 but it could have been one of other G version but anyway the weight increase was 100 kg, incl the fluid.

Juha

[Kurfürst]

I don`t have complete weight of the MW-50 system, but its easy to put together. Its a simple system, made up by:

- a 115 liter light alloy tank behind the fuel tank, weighting 32 kg.
- 70 to 85 liter MW-50 liquid in it, weighting 63 to 77 kg.
- also some piping and valves, with negligable weight

However with the installation of the rear tank the light alloy, layered dural armor behind the fuel tank, coincidentally weighting also 32 kg was removed from the 109. So in practice basically the MW-50 system added a weight equivalent of the weight MW-50 booster liquid.
When engaged, 2-3 kg of that was consumed per minute.

The complete, filled GM-1 weighted 75 kg in the Bf 109G.

Take off weight was 3080 kg with the system on this G-3 (which could mean that this 109G was a lightened variant, as often in the case of high alt fighters of the G-series).

Kurfrst - Leistungsmessung Me 109 G mit GM-1 Zusatzeinspritzung

[Soren]

The Griffon is a much heavier engine, so there's no comparison Juha.

You can compare the Griffon to the Jumo 213 or DB-603, both of which feature more HP at the different settings, and a lot more pr. boost pressure.

Fact of the matter is that the DB605 was more efficient than the Merlin as it was lighter, smaller and more powerful, which is what counts when making a fighter. And there was nothing wrong with the German fighters, all were faster than the Spitfire and easily capable of dealing with it in combat, the P-51 was the only problem because of its superior speed and high alt performance, but by mid 1944 German fighters were becoming even faster than that.

[Juha]

Soren
“You can compare the Griffon to the Jumo 213 or DB-603, both of which feature more HP at the different settings.”

Typically vague statement from Your, Now Griffon 65 used to be more powerful than the widely produced 603s (A, AA and E) while weighting around same 900 kg class. Same to Jumo 213A.

“ the DB605 was more efficient than the Merlin as it was lighter, smaller and more powerful”

Again vague. Now I and Kurfürst could not agree was the 60 series Merlins heavier or about same weight than DB 605, but 60 series Merlins were more powerful than 605A, even Merlin 25, which definitely was lighter, was more powerful than 605A at lower altitudes .

“And there was nothing wrong with the German fighters, all were faster than the Spitfire and easily capable of dealing with it in combat”

Facts Soren facts, really Spit VII – IX were faster at least high up than 109G-2, -4 and -6 at least from late 42 to very late 43 when most of the time 1,3 ata was max permitted for DB 605A. And what when wrong during the BoB and even more so in Oct 42 over Malta? In Oct 42 LW flying 109F-4s and G-2s were unable to suppress Malta airdefence relaying on from all Spits the tropicalized Spit Vs. Even in 44 in France Spits were capable to look after themselves against LW fighters. But please answer the question, why LW was unable to neutralize Malta in Oct 42, if 109s were easily capable of dealing with it in combat, with fatal consequences to the 5th Panzer Army?

Juha

[KrazyKraut]

Juha, the top speed difference between G-2 and Mk.IX is marginal and I believe is a tad in favor of the Messerschmitt (~660 km/h vs 656 km/h ??), not that it matters. The difference between F-4 and Mk.V was even a bit more iirc. I think we would agree that the Merlin was optimized for higher altitudes than the DB and will surpass the latter at some point. And I hope you don't really think that the outcome of the battles over Britain or Malta was determined by a difference of x W/kg for either fighter. We could also take the Dieppe raid or other failed attacks in 1942-43 timeframe as counter-examples. I think you overestimate the actual impact of such rather marginal performance differences.

[Kurfürst]

Originally Posted by Juha

But please answer the question, why LW was unable to neutralize Malta in Oct 42, if 109s were easily capable of dealing with it in combat, with fatal consequences to the 5th Panzer Army?

Juha

Perhaps a matter was a bit more complex than who had the better aero engines...

I am not quite sure wheter your arguement or claims about what supposed to happen over Malta makes any sense.

Its a bit like asking, why Bomber Command could not neutralize Germany, if the Merlin in Lancaster was so good...?

As to the air combat over Malta, as far as I know, it was pretty one sided. The Luftwaffe bombed the island and the ships around it continously. Spitfires were poured to Malta, with herculean efforts. Continously. I wonder why.

PS: I believe there were no two-stage Merlins outside of Britain well into the 1943. Which adds another layer of our powerplant discussion - why would you want to produce a heavier, thirstier powerplant which appearantly you can`t even produce in sufficient numbers that it very existance would be felt on the frontline?

By the start of 1943 the 109 Gruppen were throughly equipped with the DB 605A powered Gustavs; by the the start of 1944, most RAF Spitfire Squadrons were still equipped with with the single staged Merlin 45 series Mark V. There was no shortage of Mk Vs, so I suppose the Merlin 60x series was just too complex for mass production.