Which country designed the best engines for WWII?

tomo pauk said:

The shadow factories were to provide redundancy, eg. RR producing their engines in 4 locations in the UK plus in the USA?

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Shadow factories aren't coming on stream till 1939 or so. The fear of the bomber will always get through predates Shadows. Plus the Sabre is a next generation engine compared to for example a Merlin.

RR shadow organisation was different, but none of the systems were designed to build in redundancy. The RR system did, but others didn't in any case. They were designed to maximise production.

fastmongrel said:

Shadow factories aren't coming on stream till 1939 or so. The fear of the bomber will always get through predates Shadows.

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You're probably right. OTOH - there was no 'drop-in' replacement engine for the needs of the RAF in case RR factory producing Merlins is destroyed by an succesful bomb raid in 1936-1939 time frame.

Plus the Sabre is a next generation engine compared to for example a Merlin.

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Of course.
We probably will never know how much a workable Sabre was pushing RR to develop the Griffon and/or H-24 Eagle.

The whole shadow system was underway earlier than seems to be appreciated. The committee to run it was established by 1936 and in March 1936 a Mr Swinton from the Air Ministry was reporting that

"We had a 31/2 hours discussion with Bristols on Friday...They bought a complete team who could deal with everything, finance, works management and design. We were able to agree to the general lines of a vast programme involving the creation of a 'shadow industry' by them."

Obviously these things do not spring into existence over night, there were numerous firms involved and it took some time to thrash out who would do what and where, but the Bristol shadow organisation was up, running and producing by 1938.
The comparative costs I gave were for Mercury production in 1938 onward.

Rolls Royce was a different case. At the end of 1936 the Air Ministry informed the company that an annual output of 10,000 Rolls Royce engines might be required in war time. It asked the company how this might be achieved, whilst emphasising that it was not contemplating an expansion in Rolls Royce's capacity at that time. The company did not see a shadow industry as a solution. It was more sensitive about revealing technical data to potential competitors than Bristol had been (though Bristol sought guarantees that any firms participating in its shadow should not later be allowed to enter the aero engine sector) and anyway the Merlin engine was not yet ready for series production. Rolls Royce advised the Air Ministry to purchase additional machine tools, jigs, patterns and equipment which could be put into storage in case of emergency. The cost would be about £100,000 which the company suggested the government should pay.The government declined, the Air Ministry raising several objections, principally that in case of war the normal capacity of several 'motor car firms' would be available for Rolls Royce engine production.

Cheers

Steve

tomo pauk said:

Of course.
We probably will never know how much a workable Sabre was pushing RR to develop the Griffon and/or H-24 Eagle.

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When the Sabre was ordered the Air Ministry (not gifted with our hindsight) thought that there was more at stake than the technical promise of the engine itself. THE fundamental tenet of the Air Ministry's selection policy was that quality could only be maintained by competition between different firms. The contraction of the aero engine industry in the 1930s was, as shown above, a source of considerable official anxiety.
We do have an inkling on the effect of the Ministry's renewed interest in the Sabre on Rolls Royce. On 20th November 1939, following the decision to build the factory for Sabre production at Liverpool, Hives wrote the following memorandum.

"We allowed Napier's to come into the aero-engine business after the war and build up a most lucrative business which should have been ours. If Napier's had really been awake we might have been suffering from that error today. Having now established ourselves as one of the two top aero-engine producers in the country, we have got to hang on to that position, even if it costs us money."

He was clearly suspicious of the opportunity afforded to a competitor by this second war.
In 1939 the Vulture was still seen as the engine most likely to counter the perceived threat from Napier, Hives said as much to the AMDP in March of that year, but he definitely had reservations about it. It was at this time that a much simpler engine, based on the 'R' Type, what we would know as the Griffon, started serious development. It seems that Hives colluded with Supermarine (who were supposed to lose the Spitfire and start manufacturing the Beaufighter in 1941) to make it clear to the Air Ministry that the Griffon, not the Vulture, could extend the life of existing types. It was in both companies interest to extend the life of the Spitfire, in the case of Supermarine they argued that it would prevent a time consuming and costly changeover of production from one type to another, and in the case of Rolls Royce the challenge of an alternative Sabre engined fighter might be dispelled. By October 1939 the two companies had come up with a system for installing the Griffon in the Spitfire. The companies argued that this would produce a fighter equal in performance to the Typhoon , but lighter and with a lower powered engine. The smaller engine and lighter airframe would also be more economical in terms of man hours and material.
At the end of 1939, under persuasion by Rolls Royce and Supermarine, who had their own vested interests, Freeman would write to the Secretary of State that

"in wartime when it is difficult to introduce new types of aircraft without a great falling off of production, it is essential that we improve the performance of the types which are already being produced."

The order for the Sabre engine led directly to the development of the Griffon, perhaps even more importantly to radical development of the Merlin, and to the Spitfire remaining the RAF's premier fighter for several more years. None of this was intended, but seemingly innocuous causes can have drastic effects.
I would argue that it was neither the Vulture, nor the Griffon that proved Rolls Royce's answer to the Sabre, it was the Merlin, but largely because of Napier's woes with the Sabre.
It is also clear that whilst a certain degree of cooperation between companies was inevitable in the national interest, commercial considerations were never ignored.

Cheers

Steve

tomo pauk said:

Another 1st-tier engine maker is a stick against the two making a deal, that could've increased the prices while making their products less advanced. The Armstrong-Siddeley was to be the 4th, but the experiments with Deerhound went nowhere, while Tiger was a dog, not a tiger.

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I think Napiers was seen as competition for Rolls-Royce in liquid cooled engines, while Armstrong-Siddeley was to compete against Bristol in air cooled engines.

The original intention for the Deerhound was that it would be liquid cooled. The Ministry suggested that it be air-cooled.

tomo pauk said:

OTOH - looks like Fairey was not allowed to enter the race, posibly due the fears of the Air Ministry not be able to finnance five companies' designs?

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I think Fairey was no looked at favourably as they had no track record as engine designers or producers, nor did they have the required facilities to develop engines.

Also, Forsyth wasn't well liked at the Air Ministry, apparently.

stona said:

I would argue that it was neither the Vulture, nor the Griffon that proved Rolls Royce's answer to the Sabre, it was the Merlin, but largely because of Napier's woes with the Sabre.

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But only allowed to do that with the improvement in fuel, which in 1937 (or a few years to either side) was by no means a sure thing.

Yes they knew 100 octane was coming, but they weren't sure when and the 100 octane of 1935-37 was not the same as the 100 octane of 1940 which was not the same as the 100/130 of 1942.

This was an important part of engine planning. Better fuels were on the horizon but how soon they would get there and what the actual improvements would be could only be guessed at. The grade fuel put a limit on the usable pressure in the cylinder so ways had to be found to get around that. small cylinders allowed a slightly higher pressure, small cylinders could also run faster. This was the attraction of 24 cylinder engines.

Had fuel 'stalled' at 115-120PN (the rich mixture performance of BoB 100 octane) the need for the Griffon would have been much higher.
Perhaps more work would have been put into the Vulture, like taking it back off the shelf.

Not picking on the Merlin. The R-2800 would not have meet some of it's late war performance or post war success without the better fuels. Part of the R-2800s post war commercial success depended on 115/145 fuel or 100/130 with water injection. Without it airliners would have been smaller or shorter ranged or needed different engines.

Had the Merlin "stalled" at 1400-1500hp due to fuel issues then larger engines would have been needed.

Fairey don't seem to have featured in engine planning.
I will check a couple of refs in a few days when I'm home

stona said:

Fairey don't seem to have featured in engine planning.
I will check a couple of refs in a few days when I'm home

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I am not sure Fairey really had an engine "works". They may have only "built" 2-4 engines? And how much of those was supplied by outside vendors is certainly subject to question. To be fair many American companies subcontracted major parts out to vendors like engine blocks and crankcases. At least the rough forgings or castings. But it means that Fairey had no production capacity of it's own.

Shortround6 said:

I am not sure Fairey really had an engine "works". They may have only "built" 2-4 engines? And how much of those was supplied by outside vendors is certainly subject to question. To be fair many American companies subcontracted major parts out to vendors like engine blocks and crankcases. At least the rough forgings or castings. But it means that Fairey had no production capacity of it's own.

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That's certainly an interesting question.

I think a parallel question, about the entire British engine industry is why did it seem to have such a few, very dominant designers? In the few years before WW2, I don't think any single engineer at P&W or C-W was as important to their engine design process as Roy Fedden or Frank Halford.

swampyankee said:

That's certainly an interesting question.

I think a parallel question, about the entire British engine industry is why did it seem to have such a few, very dominant designers? In the few years before WW2, I don't think any single engineer at P&W or C-W was as important to their engine design process as Roy Fedden or Frank Halford.

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First and foremost the military market was relatively small. The civil market was completely dominated by just one firm, de Havilland.
There was also significant consolidation in the industry in the inter war years. All these mergers and take overs inevitably reduced the total number of design teams. Team is the important word here, not individuals. Say 'Spitfire' and everyone replies 'Mitchell'. If you are lucky they may have heard of Smith or Shenstone. It was Smith who gave a list of more than forty names, all, he considered, essential to the original design of the Spitfire.
Cheers
Steve

The engine sector was a bit different than the airframe sector. Most of the mergers and falling by the wayside had been done by about 1923 or so in the engine sector. Fedden's 'stardom' if you will rested on the Jupiter engine, which not only sold abroad but was licensed in more countries than any other aircraft engine in history. As such it also formed the basis for major lines of development in other countries.
From Gunston by way of Wiki:
" By 1929 the Bristol Jupiter had flown in 262 different aircraft types, it was noted in the French press at that year's Paris Air Show that the Jupiter and its license-built versions were powering 80% of the aircraft on display".
And at this point the Mercury and Pegasus were taking over from the Jupiter.
The E.W. Bliss company of Brooklyn New York was offering both the Jupiter and 5 cylinder Titan in the US (imported or local built I don't know) as of 1930.
Fedden and Bristol were dominating not only the British market but the world market in the 1920s and very early 30s. Fedden did not hide his own light under a bushel either. The Bristol aircraft company was owned (or rather had the same board of directors) as the Bristol Tramways & Carriage Company. A company that built and operated buses and trams over some rather large areas. Fedden's "fame" helped him deal with this board of directors to keep Bristol engines moving forward and not become an aging cash cow like Napier became.
Granted one man does not design complicated aircraft engines either but without Fedden leading the way the Bristol engine division would not have achieved anywhere near what it did.
Part of the problem in the 1920s with engine development was that many of the people involved were somewhat self taught and some had only the sketchiest formal engineering training. A success at designing a large displacement, slow turning engine of modest cylinder pressure (and there wee a number of failures) didn't always mean that a faster turning, higher pressure design was going to work.

Part of de Havilland's success was due to the Halford designed engine. Which was also licensed in a number of countries. Some light planes were flown with a almost bewildering variety of engines but the vast majority of a particular airframe are flown with one main type. The Halford Gypsy engine was of about the right power at the right time and with a considerable improvement in reliability over what had been used before. The ability to be stretched to a 6 cylinder model helped keep production costs down for the slightly bigger aircraft.

In the inter war years almost all the manufacturing of military aero engines was undertaken by the four firms I mentioned some way back.
Armstrong Siddeley and Napier were very much treading water in this period. Bristol had a share in both civil and military markets, the Jupiter was mentioned above. Nearly eight times as many Bristol designed engines were produced in Europe between 1921 and 1928 than any other design.
Rolls Royce was largely dependent on the military market.
De Havilland is the odd man out. It had captured the civil aeroplane market, but the aero engines then available in Britain were not suitable for its designs. The company decided to design its own engines for its aircraft and spent significant sums developing this business.

Actually there were engines suitable for the DH designs. But this gets back to the limited number of engine designers in England.

At the end of WWI, much like the end of of WW II there were mountains of "stuff" to be disposed off. Literally, 10,000 airframes and 35,000 engines. While some of the stuff moved fairly quickly it took until 1925 to get rid of 2,000 airframes and 3,000 engines. in part because a lot of the engines weren't very good or suitable for small private planes. In an effort to unload more of this stock Frank Halford designed an inline 4 cylinder using the cylinders from some of these surplus air cooled V-8 engines, yes a new crankshaft and crankcase was needed but the result was still cheaper than an all new engine. This line became the Cirrus line of light plane engines, used in part, to power the DH 60 Moth and other small DH designs. The Cirrus went through several models and went from up-right to inverted. At some point Halford left or returned to his private consulting firm. The Cirrus engine company eventually became part of Blackburn aircraft in 1934. By this time DH had contracted with Halford to design the......."surprise"...... Gypsy series of inverted 4 cylinder air cooled engines. By 1941 you had such different engines (sarcasm) as the Blackburn Cirrus Major which gave 150hp for take-off at 2450rpm from four 120mm X 140mm Cylinders and weighing 325lbs while the de Haviland Gypsy Major gave 140hp for take-off at 2400rpm from four 118mm X 140mm cylinders and weighed 315lbs.

So you had Halford designing the original ADC (aircraft Disposal Company) 4 Cylinder engines, Cirrus engines and the competing DH Gypsy engine. He also squeezed in the Napier Rapier at this time (used in the DH 77) and designed the Gypsy Six in 1933 although that needed some help.
One of Bristol's attempts at the light engine field (early 20s) wasn't very popular despite being installed in about 12 different airframes.

One might want to consider that despite the glowing ad copy that this was a 3 cylinder EIGHT LITER engine. 3 power impulses every two revolutions of the crankshaft. Those with extensive dental work might want to seek a different engine.

De Havilland spent £155,000 on new infrastructure, plant machinery and tools between 1924 and 1929 precisely because the company didn't want to use engines from Bristol or anybody else. Against total sales (not profits) rising from £138,495 to £676,529 in the same period this was a substantial, and successful, investment.
Cheers
Steve

Shortround6 said:

Actually there were engines suitable for the DH designs. But this gets back to the limited number of engine designers in England.

At the end of WWI, much like the end of of WW II there were mountains of "stuff" to be disposed off. Literally, 10,000 airframes and 35,000 engines. While some of the stuff moved fairly quickly it took until 1925 to get rid of 2,000 airframes and 3,000 engines. in part because a lot of the engines weren't very good or suitable for small private planes. In an effort to unload more of this stock Frank Halford designed an inline 4 cylinder using the cylinders from some of these surplus air cooled V-8 engines, yes a new crankshaft and crankcase was needed but the result was still cheaper than an all new engine. This line became the Cirrus line of light plane engines, used in part, to power the DH 60 Moth and other small DH designs. The Cirrus went through several models and went from up-right to inverted. At some point Halford left or returned to his private consulting firm. The Cirrus engine company eventually became part of Blackburn aircraft in 1934. By this time DH had contracted with Halford to design the......."surprise"...... Gypsy series of inverted 4 cylinder air cooled engines. By 1941 you had such different engines (sarcasm) as the Blackburn Cirrus Major which gave 150hp for take-off at 2450rpm from four 120mm X 140mm Cylinders and weighing 325lbs while the de Haviland Gypsy Major gave 140hp for take-off at 2400rpm from four 118mm X 140mm cylinders and weighed 315lbs.

So you had Halford designing the original ADC (aircraft Disposal Company) 4 Cylinder engines, Cirrus engines and the competing DH Gypsy engine. He also squeezed in the Napier Rapier at this time (used in the DH 77) and designed the Gypsy Six in 1933 although that needed some help.
One of Bristol's attempts at the light engine field (early 20s) wasn't very popular despite being installed in about 12 different airframes.

One might want to consider that despite the glowing ad copy that this was a 3 cylinder EIGHT LITER engine. 3 power impulses every two revolutions of the crankshaft. Those with extensive dental work might want to seek a different engine.

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An 8 L engine with 100hp output, which means it's producing much less power than the Cirrus or Gypsy from much more displacement. Engine weight tends to w proportional to displacement, so the Lucifer (what marketing wiz thought of that name?) is probably heavier, too.

The Lucifer was from the early 20s and weighed a bit over 300lbs. The inline fours of the 20s were good for a bit less than 100hp.
It took a few years before engine makers caught on that engines not only had to get the plane into the air, they had to do it without blurring the pilots vision or taking the plane apart. Curtiss making a rather bad engine in this regard, A two row 6 cylinder radial.

Shortround6 said:

The Lucifer was from the early 20s and weighed a bit over 300lbs. The inline fours of the 20s were good for a bit less than 100hp.
It took a few years before engine makers caught on that engines not only had to get the plane into the air, they had to do it without blurring the pilots vision or taking the plane apart. Curtiss making a rather bad engine in this regard, A two row 6 cylinder radial.

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Thanks. As an aside, I think that 3-cylinder radials can get perfect primary balance (The Internal-combustion Engine in Theory and Practice: Combustion, fuels, materials, design), but not secondary; you need at least 5 cylinders for that (radials with 5 or more cylinders are, surprisingly, able to achieve both perfect primary and near-perfect secondary balance, better than, say V-8s and nearly as good as V-12s)

The Lucifer (and I still think naming an engine after the prince of darkness is not a brilliant marketing move ) may not have been well-designed in that regard and was slow-turning, and possibly rigidly mounted, so every shake rattled the entire airplane, at a jaw-jarring frequency.

They named an engine "Joseph Lucas" ?!?!

Kurfürst said:

Source please.



Source please.

In any case you appear to be comparing apples and oranges, ie. bench test times for the development-stage, hand-built Metrovick jet prototype vs. the TBO which you`ve made up for the Jumo 004B production engine, out of which ca 8000 were produced (actual TBO was anywhere between 25 and 50 hours).

Anyway, the Jumo 004B completed several 100-hour bench tests in 1943, the precedessor Jumo 004A (which used high grade materials) had a TBO of 250 hours.

Just to put things into context.



Source please.



You made a claim. Its you who will have to support that claim, and not me having to disprove it.



Lets see it.



If it is well documented it will be ease for you to document it for us, too.
In any case, the thing you wish to impress us seems to be a brief bench test, 15 mins or so IIRc, of an engine under development and far from entering service.

Well DB already pushed the DB 601 to 2700 HP in 1939 for racers, these achievements being as much if not more material to the subject as the brief bench runs you come up with.



Source please.



You made that up didn`t you.

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red admiral said:

Good argument. The Germans were ahead because they produced a handful of examples of an engine that never produced anywhere close to its designed power. The allied jets were far ahead of the German ones in production in every area apart from thrust/frontal area. For that there is the Metrovick F.2 series which comfortably beats the German engines in every regard.

Kurfürst, do you have any information on the fuel consumption of DB series engines compared to the Rolls-Royce ones? The only data I've seen puts the DB series about 10% worse than the Merlin and Griffon.

The Merlin itself had some great development, going from 10300hp to 2640hp in 5 years.

With UK radials there is only Bristol in the picture. Most resources had to be spent on manufacturing and upgrading the Hercules (it was in more dire supply than the Merlin) instead of the Centaurus, which probably would have come into service around 1941/42 otherwise. The Centaurus was a great engine with a very good installation.

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Metropolitan-Vickers F.2 never successfully passed a PFTR nor did it ever enter production... its an example of what we call a "failed attempt" to build a axial flow turbojet engine...Germany was clearly ahead in jet propulsion technology by the end of the war.
Below is a comprehensive study conducted by a British author. Pls feast your eyes on it .
http://www.artefactsconsortium.org/....Transport-Lyth,JetEnginesGrPics75ppiWEBF.pdf