Napier Sabre engines

One of my all-time favourite engine.

I remember that Harry Ricardo wrote in" the high speed internal combustion engine" , that the mechanics used to manipulate the boost pressure to increase the power output which killed many of the early Sabre engines. I’m not totally sure, but I do remember there might have been some issues with starting the engines by ether, can anyone confirm this (Colum?)
 
Nicknick said:
I’m not totally sure, but I do remember there might have been some issues with starting the engines by ether, can anyone confirm this (Colum?)
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In squadron service the Sabre had to be run every day even if not for flight, otherwise it became almost impossible to start. Not sure what the problem was.
 
The ether could knock out the pilots, something which wasn"t uncommen whern using ether as starting aid (it also happend in race cars).
 
Not an expert in any way, rather a petrol head but I reckon the high performance engines of the time could do with a book of their own. Perhaps not massive tomes but concerntration on each engine in turn and I also reckon that even as bookazines they would sell in reasonable numbers.
 
There was a war on, and Rolls were proving themselves the more capable at building high-performance aero engines that worked. S**t or get off the pot, Napier.
 
Videos like this and also Gregs, have spread more disinformation than the Abwehr. Unfortunatly "nearly right" is worse than totally wrong, because people get taken in by it and swallow a load of totally unresearched rubbish along with the facts.

"in 1941 the Sabre was a great platform but the induction system was not yet optimised"

What ?

Has this person ever read a SINGLE actual archive memo or file from the Air Ministry or Napier ?
Not a single one, yet proceeds to make videos about it.
It was about two years after that when it was running in any sort of mechanically reliable state.
Even Napiers internal files admit that

1653576976922.png

Air Ministry correspondance, by the end of 1942, the Sabre was averaging 67 hours life.

1653577257125.png
Mind you, I`ve only read all the original files of Napier and the Ministry, so what do I know
compared to YouTube. God spare me *facepalm and sobs with head on hands at desk*
You know, if anyone doing these videos just emailed me and said "hey if I mention your book in
the video comment box, can you just watch this through and tell me if I`ve missed anything"?

I would gladly do it.

But nooooo, thats too easy isnt it.
(in fact I`ve actually sent messages to one channel TELLING them what the errors were and actually offering archive files
to fix it. No interest)
 
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Calum Douglas said:
Videos like this and also Gregs, have spread more disinformation than the Abwehr. Unfortunatly "nearly right" is worse than totally wrong, because people get taken in by it and swallow a load of totally unresearched rubbish along with the facts.

"in 1941 the Sabre was a great platform but the induction system was not yet optimised"

What ?

Has this person ever read a SINGLE actual archive memo or file from the Air Ministry or Napier ?
Not a single one, yet proceeds to make videos about it.
It was about two years after that when it was running in any sort of mechanically reliable state.
Even Napiers internal files admit that

View attachment 678631

Air Ministry correspondance, by the end of 1942, the Sabre was averaging 67 hours life.

View attachment 678632
Mind you, I`ve only read all the original files of Napier and the Ministry, so what do I know
compared to YouTube. God spare me *facepalm and sobs with head on hands at desk*
You know, if anyone doing these videos just bloody emailed me and said "hey if I mention your book in
the video comment box,
can you just watch this through and tell me if I`ve missed anything"?

I would gladly do it.

But nooooo, thats too easy isnt it.
(in fact I`ve actually sent messages to one channel TELLING them what the errors were and actually offering archive files
to fix it. No interest)
Click to expand...
He even says in the second part video that 3500hp at 70.6'' was achieved WITHOUT ADI ''quoting'' this Graham White part.
1653578686847.png
View: https://youtu.be/Ej7TixxfmMs?t=945

This is not only disinformation but also quoting Graham in something he did not say :(
Which btw if you go to Graham source, it is a wet rating...
1653579349733.png
With a quick google search you can find this Flight document with somewhat official figures about the VII and the use of ADI for 3050hp.
This Flight document also states the heavier weight of the Sabre VII. Meanwhile in his video he says over and over again that the Sabre VII was lighter but he didnt know how much.
 
But I guess a quick Google search is too much to ask for a ww2 engine comparation...
 
I should probably stop complaining and just make some videos which are actually correct, then everyone can choose as they see fit.
I dont have a video on the Sabre specifically, its a marvellous invention and incredibly interesting, its just not the right engine
if you have a time machine and its 1941.
People get all upset when you point out the mistakes, ITS NOT 1941 NOW. Its possible to both appreciate the great artistry AND understand why it wasnt the sucess it was hoped for at the time.
 
Calum Douglas said:
I should probably stop complaining and just make some videos which are actually correct, then everyone can choose as they see fit.
I dont have a video on the Sabre specifically, its a marvellous invention and incredibly interesting, its just not the right engine
if you have a time machine and its 1941.
People get all upset when you point out the mistakes, ITS NOT 1941 NOW. Its possible to both appreciate the great artistry AND understand why it wasnt the sucess it was hoped for at the time.
Click to expand...
Was about to say that, it would be great if you could find the time to once in a while make some videos :)
You have a great potential as a YouTuber, if that is a good thing.
 
pathology_doc said:
There was a war on, and Rolls were proving themselves the more capable at building high-performance aero engines that worked. S**t or get off the pot, Napier.
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Not according to Calum's research - or received wisdom. It is well known that back around 1930 the Ministry had firmed up its policy of buying its main aircraft's engines from a single manufacturer, and had settled on Rolls-Royce. Calum's book documents how this policy was supported by targeted development funding of the Merlin throughout the war and was the prime reason why that engine came out smelling of roses.
The higher-powered Sabre came later, to meet a forecast need beyond the reach of the Merlin. Napier had been given their head on it only because Rolls were pouring so much effort into the Merlin. One of the reasons it took so long to develop was because it did not receive the same priority, but when it got there it certainly got there. The Series 7 eventually reached 2,760 hp rated takeoff power for the Hawker Fury. By comparison the Merlin never even made 2,100 hp.
By the way, I always think that using emphatic language without first checking your facts is unwise. A sleeve valve on a chamber pot indeed! ;)
 
The Napier Sabre is a design contemporary of the Bristol Centaurus and the RR Vulture, all of which were intended to be 'next generation' after the Merlin. The Vulture was axed, so it's less well known than its rivals. The Sabre is remarkably compact for its output, and what impresses me is that they got the coupled cranks to survive, something a lot of other engines have foundered on.
 
steelpillow said:
The Series 7 eventually reached 2,760 hp rated takeoff power for the Hawker Fury. By comparison the Merlin never even made 2,100 hp.
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Given where the Merlin started, to reach 2100hp represented a doubling of its performance over its development life, not to mention a huge expansion in the available altitude range. How does the Sabre compare to that?
 
pathology_doc said:
Given where the Merlin started, to reach 2100hp represented a doubling of its performance over its development life, not to mention a huge expansion in the available altitude range. How does the Sabre compare to that?
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That's like comparing apples with oranges. The Merlin's development life was several years longer and its funding during that period was at a higher level. It went from no supercharger to single-stage to two-stage, while the Sabre was supercharged from the word go. One can argue that in initially going for a monobloc, double-helical reduction gear and messing around with ramp cylinder heads, Rolls made a series of fundamental mistakes and the production Merlin II was effectively a new engine. On the other hand Halford just had to make the bloomin' sleeve valves work. And so on.
I am having trouble cross-referencing sabre power ratings, but according to Bill Gunston's World Encyclopaedia, the Sabre rose from 2,200 hp in 1940 to 3,055 hp in 1944. In his biography of Halford, Doug Taylor gives a vague 3-4,000 hp for the Sabre.

What is worth noting is the following statistic on engine cost per horsepower, up until Halford left Napier to focus full-time on de Havilland:

Rolls-Royce built Merlins: £1 per bhp.​
Bristol Hercules: £2 per bhp​
Napier Sabre: £5 per bhp.​

So hey, you can feel happy that the Merlin was not all bad. Cheap and cheerful. :D
 
By 1944, its probably the power in the 25 to 35,000 feet range which really mattered.
It incredibly difficult to beat a Merlin-66 in that scenario until you get to a Sabre V, which
isnt really a WW2 engine, in terms of actual usage.
Important to also remember the difference in the size of cooling systems and frontal area. The "effective" power of the installations below is probably slightly less favourable than even this suggests, you cant put a Sabre in a Spitfire, and the
Sabre carries almost a thousand pounds of extra dry weight over a two-stage Merlin.
The data below is a little iffy other than the "POINTS", i.e take off, and the peaks. I dont think
the slope-off after the second gear is quite correct between them, but its enough for
a basic overall comparison. (I think the Sabre curves drop off a fraction too steeply)

1653678203150.png
 
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Calum Douglas said:
By 1944, its probably the power in the 25 to 35,000 feet range which really mattered.
It incredibly difficult to beat a Merlin-66 in that scenario until you get to a Sabre V, which
isnt really a WW2 engine, in terms of actual usage.
Important to also remember the difference in the size of cooling systems and frontal area. The "effective" power of the installations below is probably slightly less favourable than even this suggests, you cant put a Sabre in a Spitfire, and the
Sabre carries almost a thousand pounds of extra dry weight over a two-stage Merlin.
The data below is a little iffy other than the "POINTS", i.e take off, and the peaks. I dont think
the slope-off after the second gear is quite correct between them, but its enough for
a basic overall comparison. (I think the Sabre curves drop off a fraction too steeply)

View attachment 678702
Click to expand...
Calum,
Incredibly astute analysis. Thank you for bringing lucidity to this discussion.
 
According to Gunston, this Eagle was a clean-sheet design started in 1942. Somewhere I read that Halford had been told to go and tell RR all he could about the Sabre. He had done so and Hives had thanked him and promptly asked him to leave because, "We can take it from here". The Exe was very deliberately a bigger Sabre.
RR had quite a catalogue of weird and wonderful high-power "Merlin replacement" projects during its lifetime. Periodically the Ministry would cull the less promising ones, but somehow new ones kept popping up. Only the Griffon finally made the grade. Like others of its time, the Exe fell victim to the advent of the jet. H'mm, I wonder if there's a Rolls-Royce secret projects thread here somewhere...
 
There is certainly a thread about the Eagle engine somewhere. It was one hell of a machine. Yet the jets bet the heck out of it, only with the little finger. At least in absolute speed and ceiling. Piston engines resisted elsewhere for a veeeeeery long time until turboprops cut into their last stronghold.
Sic transit gloria mundi...
 
I had heard the Griffon came from the Racing engine, the 'R' from the racing seaplanes. Is that another one of the 'rumour control' nonsense files?
 
There's always some carry over inside a design organisation. I think the bore and stroke were carried over, but the Griffon has quite different treatment on ancillaries.
 
Thanks mate, I found it in the end.
 
I have now got hold of a copy of the 25 July 1946 issue of Flight, with the tailless fighter drawing and mention of the E 122 engine. It covers various aspects of Napier and the Sabre. Highlights:

The caption to the tailless fighter three-view reads; "One of several advanced designs produced by the Napier project design office at Luton. This tailless fighter was to have the 3,350 h.p. Sabre E.122 engine." This confirms that the E.122 was a version of the Sabre. The main text refers to these several designs and the engine in the past tense; "...the E-122 ... was to give 3,500 h.p." Sadly, none of the planes are described and the tailless beastie is the only drawing provided.

There is much detailed coverage of the annular radiator work. Originally conceived to tropicalise the Sabre V and featuring a fan, it was then adapted to include temperate use and the fan abandoned. Prototypes were tried on the Sabre VI and flown in both Tempest and Warwick installations. It reduced drag and generally improved handling, but was heavier.

The Sabre VII is the latest variant to be described, no mention of the VIII as such, but read on:

From the Old Machine Press website (sources provided), sorry if it's already been posted here: https://oldmachinepress.com/2020/09/20/napier-h-24-sabre-aircraft-engine/
​
"The Sabre VIII carried the Napier designation E122 and was based on the Sabre VII. The engine incorporated contra-rotating propellers and a two-stage supercharger. Four aftercoolers were to be installed—one on each induction runner leading from the supercharger housing to the intake manifold attached to the cylinder bank. Although some sources say the Sabre VIII was built, it appears to have remained an unbuilt project. The engine was forecasted to have a military rating of 3,350 hp (2,498 kW) and be capable of 25 psi (1.72 bar) of boost."​

Also a drawing captioned "General arrangement drawing of the unbuilt Sabre VIII (E122). The engine featured a two-stage supercharger and contra-rotating propellers. It was forecasted to produce 3,350 hp (2,498 kW)."
napier-sabre-e122.jpg
 
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Nice find Steelpillow, that sort of confirms something I discovered about the De Havilland DH.101, the so called Sabre Mosquito.
 
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