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ARCHIE_CALVERT
04-15-2006, 05:44 PM
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What other aircraft could have benefited from the Bristol Taurus€¦

Bristol Taurus

The Taurus was a 14-cylinder two-row radial aircraft engine, produced by the Bristol Engine Company starting in 1936. The Taurus was developed by adding cylinders to the existing Aquila design, creating a design that produced just over 1,000 horsepower (750 kW) with very low weight.
Bristol had originally intended to use the Aquila and Perseus as two of its major designs in the 1930s, but the rapid increase in size and speed of aircraft in the 1930s demanded much larger engines than either of these. The mechanicals from both of these designs were then put into two-row configuations to develop much larger engines, the Aquila becoming the Taurus, and the Perseus becoming the Hercules.
Unlike the earlier engines, where the sleeve valve was a new and untried design, the Taurus was fairly well understood and was delivered running at almost the same power it ended with, at 1,015 hp (760 kW). After several years of development, this improved only to 1,130 hp (840 kW), a testimonial to how good the first versions were.
The first Taurus engines were delivered just before World War II began and found some use primarily in Bristol's own Beaufort torpedo bomber. When the same plane was fitted with the famous Pratt & Whitney R-1830 Twin Wasp, its performance actually fell even though the Twin Wasp was both lighter and more powerful.
Nevertheless by the time the engine was in widespread production, designs had already demanded even higher power settings. The Hercules went on to see fairly widespread use, while the Taurus ended with the Beaufort after only a few years.

Specifications (Taurus II)
General characteristics
" Type: 14-cylinder supercharged two-row radial engine with dual ignition
" Bore: 5 in (127 mm)
" Stroke: 5.625 in (142.9 mm)
" Displacement: 1,550 in³ (25.4 l)
" Dry weight: 1,300 lb (590 kg)
Components
" Valvetrain: Sleeve valve
" Fuel type: 87-octane value to specification D.T.D. 230
" Cooling system: Air-cooled
Performance
" Power output:
" 1,010 hp (753 kW) at 3,225 rpm for takeoff
" 1,065 hp (794 kW) at 3,225 rpm at 5,000 ft (1,520 m) war emergency power for 5 minutes
" Specific power: 0.65 hp/in³ (29.6 kW/L)
" Power-to-weight ratio: 0.82 hp/lb (1.35 kW/kg)

Doug_Thompson
04-15-2006, 09:00 PM
Developing a sleeve-valve engine of less that 1,500hp was a mistake, IMHO.

If I'm remembering the story correctly, there was a very convincing engineering paper written in the late '20s or early '30s about radial engines. The paper's author concluded that radials would have to resort to the sleeve-valve design if they were going to grow beyond 1,500hp.

Developing sleeve valve technology was a very expesive, time-consuming proposition. It took at least a couple of years and several million Pounds, IIRC. Probably as an economy measure, either some existing parts or existing machine tools were used, restricting bore and other factors to the size of existing engines like the Perseus.

The result €" Good engines, but with a high development cost and no more power than conventional double-row 'popper' valve radials.

Worse, American firm Pratt and Whitney shortly proved that you could build conventional radials of 'popper' design that reached 2,000hp and more, although it required big investments in industrial machinery and more expense for better materials.

In 20/20 hindsight, the British would have been far better off to make a heavy investment in a sleeve-valve radial that developed at least 1,500hp. That way, they could start out where conventional radials of the day left off. Then the 1,500hp radial would have been in production by the start of the war and developed to greater HP from there. Imagine a British FW 100 in 1941, if you will.

MrBlueSky1960
04-16-2006, 07:58 AM
I would have thought the Whirly could have taken them, if you could have a prop made to take the power the 'Taurus' put out,that is. They would need to be comparable in size to the one's the 'Peregrines' used. Would they need to be made stonger?

Otherwise it would have been to much of a job to start repositioning engines,landing gears fuel tanks etc.

1000-1300hp would have been what she was crying out for. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif Would the bigger frontal area and drag they caused be off set by the extra power? Or would it make her even slower? http://forums.ubi.com/images/smilies/blink.gif

ARCHIE_CALVERT
04-16-2006, 12:51 PM
http://img.photobucket.com/albums/v187/Secudus/AircraftImages01/TaurusWhirlwind.jpg

She doesn't look to bad...

DIRTY-MAC
04-16-2006, 01:02 PM
lol nice

VF-17_Jolly
04-16-2006, 01:14 PM
An interesting side note about the napier Sabre engine of the Typoon/Tempest This engine also having sleeve valves:

The main cause of the trouble was distortion of the cylinder sleeves. Even when Typhoons began going to the squadrons, the time between major overhauls of 25 hours as laid down was often not attained. Sleeves produced by Napier often failed to reach 20 hours when tested on the bench.

By 1943, with the problem still unsolved by Napier, and with Production still lagging, the Ministry of Aircraft Production pushed through a marriage between that company and English Electric. At around the same time the Bristol engine company applied their expertise, it being discovered that their sleeves for the Taurus radial engine could be adapted by machining to Sabre size. While Napier sleeves were distorting after only 20 hours, Bristol sleeves lasted for 120 hours without any sign of real wear. A rapid decision was made to swing the production over, machine tools being obtained from the United States to give Napier the ability to bring their work up to standard.

luftluuver
04-16-2006, 01:25 PM
The 6 Sunderland centerless grinders came from those destined for the new P&W plant in Kansas City Missouri that was to make the R-2800C. P&W was not happy.

p1ngu666
04-16-2006, 02:32 PM
i imagine they ment a engine of a certain size/weight.

the 2800 is a great big heavy lump.

sleave vavles offer the best performance, all things being equal.

whirly with two sabre's imo http://forums.ubi.com/images/smilies/icon_twisted.gif

dehaviland pretty much only considered the merlin and the sabre for mossie type projects. the griffon wasnt worth the effort http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

djetz
04-16-2006, 04:17 PM
I would have said "Whirlwind" before I even opened the thread.

I agree, the whirly was a wasted opportunity.

And, as my mum would say, "if wishes were horses, beggars would ride."

Or, in this case, fly whirlies.

Low_Flyer_MkVb
04-16-2006, 04:49 PM
'A man's reach should far exceed his grasp, else what's a heaven for?'

That's Emmerson, that is. http://forums.ubi.com/images/smilies/winky.gif

ARCHIE_CALVERT
04-16-2006, 05:11 PM
Samuel Johnson 1709-1784

There is nothing which has yet been contrived by man, by which so much happiness is produced as by a good tavern or inn... http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

marc_hawkins
04-16-2006, 06:34 PM
If wishes were fishes we'd all cast nets http://forums.ubi.com/images/smilies/winky.gif

Doug_Thompson
04-17-2006, 09:00 AM
I'd bet all the early production of that engine was taken up by Short Stirlings.

As for putting them on the Whirlybird, that would have required a major redesign if it was possible at all.

One13
04-17-2006, 09:18 AM
Several aircraft designs before the war were designed to use the Rolls-Royce perigrine or the Bristol Taurus, like the Gloster f.9/37.
These two engines were similar in size & power.

The Short Sterling used the Bristol Hercules, a larger engine than the Taurus. This was interchangable with the Merlin on some designs.

luftluuver
04-17-2006, 09:37 AM
Originally posted by Doug_Thompson:
I'd bet all the early production of that engine was taken up by Short Stirlings.

As for putting them on the Whirlybird, that would have required a major redesign if it was possible at all. The Beaufighter was fitted with both Hurcs and Merlins.

The Halifax had Hurcs or Merlins.

Viper2005_
04-17-2006, 10:02 AM
The fact of the matter is that in wartime, production is king. Once a type (be it airframe or engine) is proven to work roughly as advertised, it makes a lot of sense to stick with it, irrespective of any "bright ideas" which may pop up from time to time.

There were an awful lot of "what if" engines out there; for my money the Crecy is at the top of the list.

Smaller than the Merlin, with potential to produce sufficient power that the RAE expected a Crecy powered Spitfire to attain 535 mph at 32000 feet...

MrBlueSky1960
04-17-2006, 10:29 AM
The Rolls-Royce Crecy

by Andrew Nahum, R.W Foster-Pegg and David Birch

Reviewed by Kimble D. McCutcheon

In a time when we regularly zip non-stop to nearly anywhere on the planet at speeds approaching that of sound, it is difficult to remember a world without jet engines. Some of today€s modern airline engines are approaching 100,000 pounds of thrust, and exhibit the best reliability and fuel economy of any aircraft engines ever produced. Yet, there was a time, when gas turbines were essentially unknown, and engine designers hoped to reliably achieve just 2,000 horsepower.

It was during this time, 1937 to be exact, that Rolls-Royce undertook the development of one of the most remarkable aircraft engines of all time €" the Crecy. This engine was a 12-cylinder, liquid-cooled, upright 90? -vee two-stroke. It utilized sleeve valves and was highly supercharged. It demonstrated the capacity to produce around 2,500 shaft horsepower, and was expected to have been capable of much more at the end of development. These astonishing powers were achieved from only 1,536 cubic inches of displacement and at a weight of 1,900 pounds, including contra-rotating propeller reduction gear.

The history of the Crecy€s development is chronicled in a book, The Rolls-Royce Crecy, by A. Nahum, R. W. Foster-Pegg, and D. Birch, published by the Rolls-Royce Heritage Trust in 1994. The book is really a collection of three chapters, each by a different author and two appendices rich in technical detail. Softbound, it consists of 138 pages.

The first chapter, by Science Museum Aeronautical Collection Curator Andrew Nahum, sets the stage with a short historical account of work done by Sir Harry Ricardo. It was Ricardo who championed the cause of the single-sleeve valve, stratified-charge, direct petrol injected two-stroke. While the Crecy was originally conceived as a compression-ignition engine, later work by Ricardo and the Rolls-Royce team demonstrated its potential for high power and good fuel economy when running gasoline.

The second chapter, by **** Foster-Pegg, provides a very detailed account of the Crecy€s development. The technical challenges, successes, and failures are described. Foster-Pegg was an engine tester during development of the Crecy.

Finally, David Birch, RRHT Archive editor, puts the whole program into perspective, and provides additional details of emerging technologies that made the Crecy possible in the first place. Also in the last chapter are tantalizing projections of what the Crecy could have become had it not been abandoned at the end of World War II.

Hmmm... Never heard of it, before today http://forums.ubi.com/images/smilies/blink.gif

luftluuver
04-17-2006, 10:39 AM
R-R was also working on another sleeve valve, the Eagle 22 (46l/2807ci), an H engine simular to the Sabre.

rated @ 3500hp @ 3500rpm
weight 3900lb http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif
2s/2s turbocharger with each bank having its own aftercooler (total 4)

Doug_Thompson
04-17-2006, 02:07 PM
As official naysayer of this "re-engine the Whirlwind" project, duty compels me to point out that different engines probably wouldn't have solved the high landing speed problem.

Moreover, was this particular swap of engines ever tried, or proposed?

Finally, one of the major disappointments in the Whirlwind was it's limited range for a two-engine type. Would the Taurus have improved on the fuel consumption of the Kestrel?(edited p.s. Oops. I meant Peregrines, not the older engine they were derived from.)

ARCHIE_CALVERT:

Very nice picture. Think you can do a radial-engined Hurricane?

Low_Flyer_MkVb
04-17-2006, 02:50 PM
Stick with Peregrines - with all their faults - I say.

Got the Whirly to Antwerp and back, you know...

ARCHIE_CALVERT
04-17-2006, 03:37 PM
"Originally posted by Doug_Thompson:
As official naysayer of this "re-engine the Whirlwind" project, duty compels me to point out that different engines probably wouldn't have solved the high landing speed problem."

It was never a problem, even the A&AEE report discount this. It was stated that the landing speed did not appear to be fast for the pilots. It's a myth.

"Moreover, was this particular swap of engines ever tried, or proposed?"

Sir Roy Feddon was always trying to promote his Bristol Engines, but Petter would not be moved away from his original design concept and the 'Neat' nacelles of the Whirlwind stayed. His stubbornness on this, negated a fine aeroplane to the history books as an 'also-ran' of aviation... Westlands did in fact solve the fitting of Merlin€s (Merlin XX's) to the Whirlwind, again one of the arguments against this installation was that the airframe could not take it! Westlands solution with undercarriage retraction would have given the aeroplane outstanding performance, estimated top speed of 400-410mph, a service ceiling of 37,000 ft and a range of 900miles. The Ministry took no action with this breakthrough, Nither did they when 'Napier Daggers' were put forward as a replacement, or again by Beaverbrook/Dowding letter, that implies westlands had earlier than Oct '40 , offered to fit American engines to the whirlwind. Presumably the V-1710's of the P-38
It seems the Whirlwind face did not fit with the men from the ministry...

"Finally, one of the major disappointments in the Whirlwind was it's limited range for a two-engine type. Would the Taurus have improved on the fuel consumption of the Kestrel?(edited p.s. Oops. I meant Peregrines)"

720 miles... http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Doug_Thompson
04-17-2006, 03:42 PM
... but Petter would not be moved away from his original design concept and the 'Neat' nacelles of the Whirlwind stayed. His stuborness on this, negated a fine aeroplane to the history books as an 'also-ran' of aviation.

Even I am moved to sympathy, in that case.

Here's a thought: Give it two Taurus engines, put two of those Vickers 40mm guns in the nose instead of 4x20mm, and send it tank-hunting over the desert.

ARCHIE_CALVERT
04-17-2006, 04:08 PM
So, to sum up€¦

1) When the descision to stop Peregrine production was made the Air Min was given the chance to fit American engines in place of them but the RAF didn't take them up.

2) Jan '41 Westlands offered the Merlin XX engined Whirlwind , but the offer wasn't taken up, the offer was real as the u/c retraction problem had been solved by Westlands.

3) R-R actually took the Peregine/Whirlwind serious and as soon as time permitted modified a Whirlwind in late '40 / early '41 , experimenting with different radiators, oil cooler installations and carb intakes, test showed a substantial increase in ceiling and top speed, The aircraft was sent to the RAE at Farnborough for test , but again the suggestions were not acted on, and the a/c returned to Westlands , who were told to return it to standard before re issuing it.

4) Whirlwind/Peregrines also used 100 octane fuel, some articles mention they could only use 87 octane.

These little known facts have been substantiated by Mr Jerry Brewer who has delved into the Whirlwinds past for over thirty years€¦

MrBlueSky1960
04-18-2006, 02:34 AM
"3) R-R actually took the Peregine/Whirlwind serious and as soon as time permitted modified a Whirlwind in late '40 / early '41 , experimenting with different radiators, oil cooler installations and carb intakes, test showed a substantial increase in ceiling and top speed, The aircraft was sent to the RAE at Farnborough for test , but again the suggestions were not acted on, and the a/c returned to Westlands , who were told to return it to standard before re issuing it."

What! http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif Bloody Hell, I sometimes despair and wonder how we ever won the War... http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif

Sergio_101
04-18-2006, 03:05 AM
Sleeve valve engines were the answer to the
major problems with the consumption of exhaust
valves on poppet valve engines.

Sleeve valve engines were a neat idea that
never really worked as advertized.

Reason was that the problems with poppet valves
were solved. The solutions were, sodium filled valves,
single piece forged/cast heads, and the dramitic
increase in octane/PN ratings in fuels of
the late 30's.

yes, there were a number of successful sleeve
valve engines, and the Sabre made an impressive
power output.

But look at the Prat&Whitney or Wright radials
of comparable displacement to the Bristol
radials.
All were developed to higher power levels.
Engine life was pushed into the thousands of hours.

As I have seen, sleeve valves have issues with
failures at very high boost pressures.
After poppet valves lost the failure problem
Sleeve valves became a side show.

Sergio