Yes but imagine adjusting the tappets of 24 cylinders outside in the middle of winter!
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Yes but imagine adjusting the tappets of 24 cylinders outside in the middle of winter!Cylinder block spacing was more defined by the crankshaft swing than the sparkplug spacing
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Sabre engine.
The Sabre spark plugs were not all that easy to change.
Yes but imagine adjusting the tappets of 24 cylinders outside in the middle of winter!
And later Griffons were lighter still (though heavier than the VI), and had a two stage supercharger, hence better at altitude.Very little attention seems to be given to the weight of the engines spoken about here. Given that the Rolls-Royce Griffon, in Mk VI form, gave well over 2,000 BHP, makes it a rival to the Napier Sabre. The Mk VII Sabre weighed 2540 pounds, the Griffon just 1790 pounds. I am an admirer of the Napier Sabre, (I read Setright's "The Power to Fly" at an early, impressionable age!), but it certainly would appear that the Griffon was the better choice....
I read Setright's column in Car magazine for many years. If there's is two things I gleaned it's that he loved sleeve valves and despised Rolls Royce. He also claimed that the only use for seatbelts was to hold grocery bags and the smoking was good for you. He died of cancer although I'm not sure of what kind.Very little attention seems to be given to the weight of the engines spoken about here. Given that the Rolls-Royce Griffon, in Mk VI form, gave well over 2,000 BHP, makes it a rival to the Napier Sabre. The Mk VII Sabre weighed 2540 pounds, the Griffon just 1790 pounds. I am an admirer of the Napier Sabre, (I read Setright's "The Power to Fly" at an early, impressionable age!), but it certainly would appear that the Griffon was the better choice....
Yes the problem was the Sabre`s put through the initial Ministry test were all hand crafted prototypes, it took several attempts and essentially the engines were rebuilt and hand fettled until one managed to get through the test. So it "passed" but it would be years before it was actually ready for reliable mass production.Yes, the Griffon was a most interesting engine. But it ran for the first time in June 1940, when the Sabre had made its first type-test mid-1938 !
Per Wikipedia, the Typhoon entered service in September 1941, vs the first Griffon Spits in October 1942, so by that time the gap had narrowed to one year. And of course, the Sabre gave no end of trouble for the entire war and was retired from service relatively soon after the war, whereas the Griffon soldiered on until the 1980'ies in the Shackleton.Yes the problem was the Sabre`s put through the type test were all hand crafted prototypes, it took several attempts and essentially the engines were rebuilt and hand fettled until one managed to get through the test. So it "passed" but it would be years before it was actually ready for reliable mass production.
Yes the problem was the Sabre`s put through the initial Ministry test were all hand crafted prototypes, it took several attempts and essentially the engines were rebuilt and hand fettled until one managed to get through the test. So it "passed" but it would be years before it was actually ready for reliable mass production.
This 1938 "pass" was also not a 100 hour full type test approval for service, it was an "initial acceptance test". The proper type test 100 hour was not done until June 1940.
See Napier case history file (in my book, see refs for Chapter 2: "1930`s prelude to war" archive file ref No.70, on page 463.)
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The Sabre cannot have "given no end of trouble", since only ~5,000 were built, and well over 4,000 planes flew with them, so there weren'tPer Wikipedia, the Typhoon entered service in September 1941, vs the first Griffon Spits in October 1942, so by that time the gap had narrowed to one year. And of course, the Sabre gave no end of trouble for the entire war and was retired from service relatively soon after the war, whereas the Griffon soldiered on until the 1980'ies in the Shackleton.
The Sabre cannot have "given no end of trouble", since only ~5,000 were built, and well over 4,000 planes flew with them, so there weren't
that many spare engines to keep on hand. The Tempest F.6 flew with Sabre power for years postwar operating in harsh primitive conditions,
from RAF airbases in hot dusty Africa/Middle East zones, & the RAF were flying its Tempest TT5s hard in realistic gunnery training exercises
for their 'jet-jockeys' right up 'til the mid 1950s - when Meteors were deemed available to take over the role.
Not sure I`d have to go and check and I cant remember which file that was in now.Is the Tornado mentioned in the first page the Centaurus Tornado?
Well see para 158, he was in overall control over the entire program at the Air Ministy. But you cant just "cancel" orders for an engine you dont like half way through a war when you have a major aircraft program underway which relies on it being delivered.Have you got similar documentation dated after Spring 1943, which is the point in time when Napier's had received the Bristol Taurus sleeves and had the centreless grinders in operation making the sleeves? All the pages above appear to be prior that that.
I don't think anyone can claim the Sabre was any good prior to that point. The Squadron ORBs show they managed to get sufficient reliability for standing patrols, but I would put that down to the herculean effort of mechanics to keep them running.
I was surprised they stayed in production until 1946. Whoever labelled it a "miserable failure" must not have had much clout when it came to purchase orders.
Its a retrospective Air Ministry file, which was a review file the Ministry made of all major departments and projects to ensure learning was there for the future, recorded right afterwards when the events were all fresh in their minds, those particular pages were written about two years after the war. He is saying that the Sabre project as a whole, given the initial hopes and promise had been a failure. It is difficult to argue with that looking at the rest of the conclusions from wartime papers, many of which I posted above.1946 is well after the war. A huge amount of orders were cancelled in 1945. If the Sabre was a "miserable failure" in 1945, surely it would have been cancelled as well.
1946 is well after the war. A huge amount of orders were cancelled in 1945. If the Sabre was a "miserable failure" in 1945, surely it would have been cancelled as well.