Re Engined Radials

Well I don’t know that the splines on the propeller shaft would be the same for the Centaurus and the R-3350 engines (unless there was some allied wartime standardisation?) so at the very least a new spider would need to be designed and manufactured (and probably certified). None of this would be quick, easy or cheap.

Besides why would you want to change the Centaurus in a sea Fury? There may be anecdotal evidence that the Centaurus is unreliable but I think the R-3350 was originally fitted by those who wanted to air-race the Sea Fury in the US and the supplies of parts were more plentiful and there had been more work done on the R-3350 to increase the power output.

I know most people admire the ‘look’ of an aircraft but to my mind the engine is as important as any other aspect of a vintage aircraft, possibly even the most important aspect because the engine turns it from a sculpture into an aircraft. If you want to separate the authenticity of airframe and engine fine, but ask yourself this:

If there were a problem with the airframe of a Spitfire, would you be happy to replace that airframe with that from a Balliol to keep the Merlin engine flying?

The Centaurus is also a very important aero-engine historically. Britain was the only country to produce large numbers of sleeve-valve engines and to use them successfully. The manufacture of these Bristol engines is a story of dogged determination and engineering excellence that shouldn’t be forgotten, and that should be a lesson for anybody today.

There are very few chances to see a sleeve-valve engine powered aircraft flying but those chances are getting better in the UK. I’m sure the RNHF will sort out the problems with their Sea Fury Centaurus engines and we will once again see these beautiful aircraft in our skies as a tribute to all those that designed, built, maintained and flew them.

You will have to excuse my ignorance if the answer to this question is simple…

There is often criticism of the look of a R3350 re-engined Sea Fury because of the “missing” prop blade, so the question is, why can’t a normal 5 bladed Centaurus prop be fitted to the R3350 engine to maintain the original “look” of the aircraft.

Thanks

Mark

Centaurus

I was always under the impression that although the Centaurus was a very complex powerplant,it was also a very reliable unit that offered great performance.
It was obviously easier to maintain in service because there would have been plenty of new spares available for what were then relatively new units.
Indeed if neccessary I’m sure the units would have just been changed out completely if there was a rogue.
Thesedays however with the Centaurus being fifty odd years old and serviceable spare parts as rare as rocking horse ****, operation and maintenance has become a problem.
This leaves me wondering if The Fighter Collection have a reliable fix for the Centaurus with several Furies under their care.Their restoration of the ex RAF Museum Fury looks great,a lot of time and money invested in it not to have a reliable powerplant.
I would have thought someone must be able to overhaul them to a reliable condition safe for flight.

Steve

Am I missing something here, are Centaurus powered aircraft grounded now?
What about SFs VR930, VX281 (both RNHF), WG599 G-BWOL, WG655, WH587, WH588 G-EEMV, WH589, VX653 G-BUCM, all of which I thought were Centaurus flyers?

WH588, G-EEMV has not flown since its tragic fatal accident at Sywell May 2001:(

The new owner also brought the spare Centaurus and i understad that he is now intending to refit a Cetaurus rather than his intitial plan to fit a Corn Cob engine.

Yes, I actually meant the Taurus instead of Aquila (which I’d forgotten about). 😮

…the only Bristol sleeve valve engines that I have seen are all seized…

Seized sleeves are certainly a problem for engines that have not been run for a long time; was that true of the ones you have seen?

Apparently the Bristol Taurus also used the same size bore as the Aquila, these (together with the early Napier “H” engines) are thought to have been directly influenced by the paper published by Harry Ricardo (in 1927) on sleeve valves; it has been suggested that the offices of Harry Ricardo were adjacent to Frank Halford’s at this time!

The Sabre was prone to the sleeves seizing, and certainly the only Bristol sleeve valve engines that I have seen are all seized, which is slightly at odds with the main failing of the sleeves, which is to seal correctly,(when worn) and the associated high consumption of oil, but apparently the two aren’t mutually exclusive.

One thing that almost never gets mentioned is that by flying preserved aircraft it is also possible to preserve maintenance skills and knowledge that would otherwise be lost. Aren’t these just as worthy of preservation?

Are there actually ‘reliability issues’ with the Centaurus?

That is exactly what I am trying to fathom out. It has been said above that both RNHF Sea Furys are down with engine issues. Well surely if they had two aircraft powered by 3350s the same scenerio could happen?
I do except that the second engine is more operator friendly, in numbers, spares and trained personnel.
But the Centaurus would have to be appreciably worse than the 3350 for it to be worth changing engines (and all the associated componants down to the brakes) and going through the inspection and certification process.

Ozplane asks how they managed with the apperently unreliable Centaurus in service, well don’t forget for one spares (inc whole engines), tools, handling equipment, and type rated air mechs were plentiful.
But also I have not heard of it being especially unreliable, the Beverley saw long and ardous service all over the world, the Ambassador saw fairly lengthy service with the second-line airlines apparently without prohibitive powerplant problems.

…fitting R3350’s to the RNHF Sea Fury’s could well overcome the reliability issues with the Centaurus…

Are there actually ‘reliability issues’ with the Centaurus?

I would have thought that the real problem would be one of spare-parts rather than any inherent reliability issues. Fifteen years ago I was told that the rebuild being done then of a Centaurus for the RNHF was the last one that could be done with ‘new’ pistons or sleeves and any more rebuilds would have to use ‘part worn’ spares.

Also would the R-3350 be any more reliable or is it just a case of more spares being available? In any case the rebuild would probably have to be done in the US (as is the case for the Centaurus) because there is enough critical-mass over there to support specialist engine builders.

Would it be possible, even if prohibitively expensive, to have new parts manufactured or are there ‘certification’ issues?

No problem David. I just hope de Havilland Support are still around to help with approval when the Hornet is ready to fly!!

yeah, that’ll look great with a couple of Pratt & Whitney radials up front! 😀

No problem David. I just hope de Havilland Support are still around to help with approval when the Hornet is ready to fly!!

David, read my note #7 in this thread and that gives you the process. It’s always easier and cheaper if somebody has done it before you and I guess the Buchons are covered by the work done for the B of B movie if not by the re-imports in later years.

Thanks Ozplane, I’ll put my reading glasses on next time! 😀

Hi Mark,

That’s no problem, I’m just interested, as yourself in the future of seeing a lot of non-Merlin powered types continuing to fly in the UK.

This raises the question which perhaps one of the Spitfire experts on here could advise on – how interchangeable are the Merlin and Griffon engines in a Spitfire and what “approval / certification” would be required if you were to “re-engine a Merlin powered spitfire with a Griffon” or would it be a different process as both engines are type approved.

David, read my note #7 in this thread and that gives you the process. It’s always easier and cheaper if somebody has done it before you and I guess the Buchons are covered by the work done for the B of B movie if not by the re-imports in later years.

Hi David, sorry for not giving credit where credit is due, after all it is your initial query which sparked off this whole thread.

Kind regards

Mark

Hi Mark,

That’s no problem, I’m just interested, as yourself in the future of seeing a lot of non-Merlin powered types continuing to fly in the UK.

Here’s a couple of examples:

– German Storch can be powered by a german engine.
– post war french built storch can be powered by an argus engine.

– Me109 with a DB engine
– post war Buchon with a Merlin.

Although these are individually very similar looking aircraft, I guess the alternative powerplants, systems, and aerodynamics make each different types. So to achieve the same approval today to put X engine into Y airframe, would this mean this sort of change would need a new type approval? I just wonder if a CAA process is available for this, and if so, is it just hindered by the lack of capital required to pay for a full test program by the potential owner?

“Without drifting this thread into “re-fitting” another radial into this airframe type thread, if an aircraft were to have an alternative type of powerplant fitted, in the UK would this effectively become a new type, and would it need type approval accordingly? Is there a process that exists that would cover this here?

For example in the world of light avaition, a particular airframe can support various types/makes of engines. If an an engine has similar torque + power output, revvs, adaptable systems, and is compatible with the sort of flight envelope originally intended for a type, can this also be substituted for another?”

Hello Mark,

Actually these two paragraphs you quote, were my question, not David Burke’s if you re-read the previous thread. However, as you say I believe it is a valid question to ask. We face the prospect of having plenty of ground-hogging Sea Fury’s, Tempest II’s, Walrus, etc. in the UK otherwise.

Hi David, sorry for not giving credit where credit is due, after all it is your initial query which sparked off this whole thread.

Kind regards

Mark

Just a little not-pick – in the pursuit of historical accuracy…It isn’t ‘Ash’ – but ‘ASh’.

Sorry, I’ll try to do better next time. 🙂

Actually I’ve just got a copy of ‘Russian Piston Aero Engines’ by Vladimir Kotelnikov; is it any good?

Am I missing something here, are Centaurus powered aircraft grounded now?
What about SFs VR930, VX281 (both RNHF), WG599 G-BWOL, WG655, WH587, WH588 G-EEMV, WH589, VX653 G-BUCM, all of which I thought were Centaurus flyers?

No, but recently the RNHF Centaurus-powered aircraft seem to have spent a lot of time with unserviceable engines (and I say that without it being any form of criticism).

How do the ‘new build’ FW190 get around this problem?

The engine options are a Chinese licensed Ash-82 or an Allison V-1710, obviously neither was originally fitted. Are they considered re-engined originals or have they been certified as a new type?

Just a little not-pick – in the pursuit of historical accuracy…

It isn’t ‘Ash’ – but ‘ASh’ – the first letters of the designers name – Arkady Shvetsov.

And before you ask ‘Sh’ is one letter in the Cyrillic alphabet.

Ken

The sea fury does sound wonderfull, as does the Blenheim, with regard to the former, you might just have to take my word for it!

Am I missing something here, are Centaurus powered aircraft grounded now?
What about SFs VR930, VX281 (both RNHF), WG599 G-BWOL, WG655, WH587, WH588 G-EEMV, WH589, VX653 G-BUCM, all of which I thought were Centaurus flyers?