Napier Sabre III engine !

Hi all.

I know this thread is some years old now but I am trying to collect information on the Napier Sabre engine. I am a member of AEHS which is a great source of information on Aero Engines.

I would be very interested in getting a copy of the Sabre engine manual that is shown on this thread.

I think if the museum scanned it in high resolution there would be a demand for PDF format copies. In this format there would be no need for post.

I would be grateful if someone could get back to me on this.

Best regards, Geoff

Hi Ben,
This actual manual belongs to the Aviation Heritage Museum in Perth, Western Australia. I have talked with the manager of the museum and he wonders are there any people out there that would want a copy and how much would they pay for these copies as they are a private museum and any revenue goes to keeping it going. I see windhover has replied with a page of information about the engine. So maybe there are other manuals or an outlet that you can get this Air Publication 1810A Volume 1 from free. So again if there is nothing else out there, how much would be reasonable to pay for a copy + postage

DADE , Thank you for sharing those fab looking drawings , Are prints or copies of that manual available anywhere ?

I think the definitive account about the solution of the Sabre sleeve production issues is available in the book, I KEPT NO DIARY by Rod Banks, an incredible book! He gives considerable insight on this, and many other topics. Very well worth reading!

V

Not a Napier but you can see the technology taking root..
https://oldschool.co.nz/index.php?/topic/53938-bugatti-t5759-engine-project/#entry1752201

Not that much of a goodwill gesture: as I understood it there was need for considerable compulsion by the Ministry/government before they gave any assistance whatsoever to a rival.

From what I can remember, the compulsion was regarding NOT getting certain upcoming/further contracts if they didn’t help Napier, so much for all pulling together for the war effort

Not that much of a goodwill gesture: as I understood it there was need for considerable compulsion by the Ministry/government before they gave any assistance whatsoever to a rival.

Napiers eventually overcame the shortcoming of their engine sleeves by using the Bristol Engines’ method of manufacture. This was to centrifugally cast and then satin hone them to precise tolerances afterwards – a method/process handed over by Bristol to Napier’s as a goodwill gesture. There was a war on after all.

Bristol’s had ploughed huge resources into perfecting the mass-production of the sleeve, this being crucial to the production, or not, of a reliable power plant (they built Hercules, Perseus, Taurus and Centaurus sleeve valve engines during the war). It is worth pointing out that the sleeve valve was, in many ways, far better than the poppet valve and seen as many as the way forward as piston engines output increased more and more.

The sleeve valve was far more tolerant of back-pressure (such as would have occurred with a turbocharger, though here in the UK we chose not to go down that path for larger engines) and it led, with the Hercules 264 in the Varsity, to the longest overhaul life of any piston engine produced before or since – typically 3000 hours.

Properly appraised and managed, there is no reason why the sabre cannot be a good and reliable power plant in a restoration. Its early troubles gave it an undeservedly poor reputation but, in the end, with all the bugs ironed out, it was one of the finest high-power piston engines in service.

With its continued use after the war and very limited application I’m always surprised that there aren’t far more Sabre engines around than there are. Perhaps it was its large and compact size that made it such a good candidate for the scrapman’s beady eye?

Anon.

If anyone has read the true history of the R-3350 -57 AM they will know that the issues suffered by the first of the mass-produced Sabres were nothing in comparison. The R-3350 almost bought the entire B29 project to a grinding halt, and indeed even as last as August 1945 Colonel Paul Tibbets refused to fly the Atomic mission unless his aircraft was equipped with specially modified engines. The Sabre once they understood how to manufacture the sleeves correctly only needed to be managed correctly, a task a few courts martial soon sorted out. A family friend flew some 60 missions from the Normandy beach heads and beyond without an abort, hardly the record of a poor engine.

Yes true…you’d be able to do it only if there was a need for upgraded Napier Sabre for instance for caterpillars etc.

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Quite so – I think his next machine was going to be an A-26. Lovely bloke much missed. TT

And if anybody had the facilities and knowledge to produce modern replacement parts, or even improved replacement parts, it was Paul Morgan; such a tragic irony, the nature of his passing.

Before his sad passing Paul Morgan was engineering solutions to make a Merlin run more efficiently and to begin production of new parts. He was also fascinated by the Centaurus and IIRC had already begun machining new sleeves in modern metal with a view to improving reliability.

TT

As long as money is no factor, it will not be a problem to restore, or even to produce a reliable Sabre engine. The owner of the BMW driven 190 had no problems to spend any amount to solve problems, which appeared during the restauration and the tests of the engine. I am not shure, if this is the same with the groups, which are going to restore the Sabres for their projects. Just for example. If there are some minor chips in the filter of a Merlin engine, there are easily 200000 Dollars needed to solve the problem. As we all know, nearly all parts of an Allison or a Merlin are available. Collecting airworthy or reproduced parts for the Sabre will be much more challenging and expensive.

If anyone has read the true history of the R-3350 -57 AM they will know that the issues suffered by the first of the mass-produced Sabres were nothing in comparison. The R-3350 almost bought the entire B29 project to a grinding halt, and indeed even as last as August 1945 Colonel Paul Tibbets refused to fly the Atomic mission unless his aircraft was equipped with specially modified engines. The Sabre once they understood how to manufacture the sleeves correctly only needed to be managed correctly, a task a few courts martial soon sorted out. A family friend flew some 60 missions from the Normandy beach heads and beyond without an abort, hardly the record of a poor engine.

Yes, there is no doubting that the Sabre is a complex beast…

…although, the advocates of sleeve-valves would say they had fewer moving parts than the equivalent poppet-valve designs!

While I think there is a case for ‘fewer parts’ in some sleeve-valve designs, the Bristol Hercules for example, I’m not convinced that a pure part-count has much bearing on reliability; many of the more numerous parts in the poppet-valve designs are very simple (and reliable) washers, collets or springs so a direct comparison of part-court versus reliability is unrealistic.

As for ‘engineering madness’, well, you may have a case, but there is a very fine line between madness and genius! I wonder what design-criteria drove Frank Halford to choose the H-24 layout over, say, a single ‘flat-12’ design; presumably overall dimensions / frontal area?

And it had worked-out before in an ‘unnecessarily complex’ engine…..the Napier Lion.

The B-29s essentially fly with B-50 engine configurations I believe? .

AFAIK the original Wright R-3350 -57 AM engines were replaced by new engines built using parts from later model engines that powered the Douglas A-1 Skyraider and C 119 Boxcar, a custom built combination of the Wright R-3350-95W and Wright R-3350-26WD engines.

True, but is the Sabre not being judged as ‘unreliable’ based on its early combat service?

My comment above is purely because of the total number of moving parts in the Sabre – engineering madness at its best (a Napier speciality).
Whilst i do agree that some of the Sabre technical problems had been addressed before 1945 – it was always a difficult/tricky engine to maintain,I would imagine that the post war Tempest TT5 fleet was kept running because of (presumably) an ample supply of spare engines left over from WW2.

The B-29s essentially fly with B-50 engine configurations I believe? And how many FW-190s are active with original engines – the new builds use Russian engines.

One original Fw-190 with the BMW engine, soon to be joined by a second in a year or two.

A Jumo 211 is about to begin testing for a Stuka, along with I believe two more 211s in progress for other unnamed projects. Soon to be followed by a Jumo 213 that is almost back together.

The B-29s do not fly with B-50 engines but a special configuration of parts from the most durable 3350 series engines.

Rebuilding a Sabre is a daunting task, but at least they have several mostly undamaged and unmolested cores to start with and can easily exercise them on test rigs while on the ground.