FLYBOYJ
"THE GREAT GAZOO"
Be advised that you're replying to a post from 2008 and to a member who was banned a long time ago.
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Be advised that you're replying to a post from 2008 and to a member who was banned a long time ago.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
Be advised that you're replying to a post from 2008 and to a member who was banned a long time ago.
I was replying to red admiral's post..I believe he is not banned..The thread is old but still alive
And that it is, just didn't want your efforts to go unanswered, but do appreciate you reviving this thread.I was replying to red admiral's post..I believe he is not banned..The thread is old but still alive
The key powers US, Germany, Japan and England all made great engines.
Speaking for liquid cooled Germany, Allison and Merlin in that order.
US or Germans Liquid cooled engines were just more rugged.
Merlin was called the Watchmakers Engine..it performed well because of a great Supercharger system that Allison never quite caught up.
Germany had the variable Supercharger which was a huge asset.
Radials ..everyone had a good radial.
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...
Mike Nixon of Vintage V-12s has told me the DB 601/605 has very good internals. The biggest problem was feeding them NO2 and over-boosting them to get powers that weren't conductive to long engine life. You can only push powers so high until something breaks and they needed more power without the time to strengthen the engine sufficiently.
I think your quote about Sabre engines is a little harsh. Yes early Napier's were very unpredictable and suffered a litany of problems especially with fire during engine start, and a few other minor gremlins that were concerning the RAF. But at that time Britain had to work with what it had, and later Sabre variants (Especially Tempest V's powered by the Sabre ll) Had almost all problems eradicated, and many Luftwaffe pilots stated the Tempest was one of, if not the best fighter the allies possessed towards the end of the war. Further development of the British H-24-cylinder, liquid-cooled, sleeve valve, piston aero engine, designed by Major Frank Halford and built by D. Napier & Son, would surely have given the Merlin or Griffon serious consideration and respect. As for Britain having just a few types of modern powerful aero engines i think is irrelevant. From inline to radials, Britain could hold its own with any other country during ww2. Plus a lot of people forgey the Napier Sabre H-24 Mkl was first tested way back in 1939.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
Look at the Luftwaffe technical notes about maximum permissible boost on the Db605 and the 1.3ata limit (instead of 1.42) until piston tops could be reinforced, for starters. As pistons were being burned through. They did eventually solve this but I would note that the solution was simply to add more mass to the top of the pistons...
I burned through many pistons on two strokes, I know it is different technology but when the process starts it takes seconds or minutes not hours.The thicker pistons just meant it took a few more hours for the detonation to eat through the piston crowns.