Radial Engines
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411,
When Douglas designed the DC7 and were looking for an engine over 3,500 HP Pratt developed the 4360.
As I said Douglas went for the CW because of weight.
I find it strange that Douglas never even considered it because there was not exactly a plethora of 3,500 HP engines out there!
The 4360 was also used used in the C119-C
When Douglas designed the DC7 and were looking for an engine over 3,500 HP Pratt developed the 4360.
As I said Douglas went for the CW because of weight.
I find it strange that Douglas never even considered it because there was not exactly a plethora of 3,500 HP engines out there!
The 4360 was also used used in the C119-C
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Got the T shirt
The 4360 design was started long before the DC7 was ever thought of...as I mentioned before, specifically for the B36.
When the 4360 was installed on the Stratocruiser, the rear row of cylinders (four rows of seven) ran very hot, simply because the 'twist' (ie; cylinder row offset) was the wrong way 'round, as the engine had been developed for a pusher design.
Sorry...never considered for the DC7...as I grew up less than a mile from where ALL of the DC7's were built, and knew many of the folks involved (engineering project manager a close relative), the 4360 was never on the designers table.
Flew 'em as well...nice aircraft, but noiser than the DC6 (except for the -7C)
Nice try tho....
The 4360 design was started long before the DC7 was ever thought of...as I mentioned before, specifically for the B36.
When the 4360 was installed on the Stratocruiser, the rear row of cylinders (four rows of seven) ran very hot, simply because the 'twist' (ie; cylinder row offset) was the wrong way 'round, as the engine had been developed for a pusher design.
Sorry...never considered for the DC7...as I grew up less than a mile from where ALL of the DC7's were built, and knew many of the folks involved (engineering project manager a close relative), the 4360 was never on the designers table.
Flew 'em as well...nice aircraft, but noiser than the DC6 (except for the -7C)
Nice try tho....
Lots of info on the web about the Sabre.
Ran 3,500hp at 3,850 revs. Triple 2 stage supercharger used an enormous 400hp.
Finally tested to 4,000hp ( and this in 1942/4 no exact date.) Fascinating story about improved sleeves coming from the Bristol Taurus.)
Prototype Wyvern was lost when the Eagle quit and the prop would not feather for forced landing. Not Westland's greatest plane.
Ran 3,500hp at 3,850 revs. Triple 2 stage supercharger used an enormous 400hp.
Finally tested to 4,000hp ( and this in 1942/4 no exact date.) Fascinating story about improved sleeves coming from the Bristol Taurus.)
Prototype Wyvern was lost when the Eagle quit and the prop would not feather for forced landing. Not Westland's greatest plane.
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I visited the RNZAF museum at wigram last weekend on their open day and had a look at their sectioned Sabre.Quite complex but not as physically large as i would have thought for the output it achieved.
They also had a sleeve valve demonstrator there of the turn the handle type, A couple of turns while watching the sleeve do its stuff and its workings becomes crystal clear.Clever stuff.
They also had a sleeve valve demonstrator there of the turn the handle type, A couple of turns while watching the sleeve do its stuff and its workings becomes crystal clear.Clever stuff.
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411,
[Sorry...never considered for the DC7...as I grew up less than a mile from where ALL of the DC7's were built, and knew many of the folks involved (engineering project manager a close relative), the 4360 was never on the designers table.]
The following is quoted from World Encyclopedia of Aero Engines by Bill Gunston
“The Mighty R-4360 had already passed its first test by June 1942 and later in the year was qualified at the unprecedented rating of 3,000 HP.
By VJ day it had been qualified at 3,500 HP.
The last throw was the R-4360 compound, which went beyond 4,000 HP. The vital application was the DC-7 and Wright won because the Turbo Compound was lighter and simpler. “
Of course this is a British Book, and Bill Gunston is a respected (but British)writer , I do live several thousand miles for where both the engine and DC7 were built and most of my relatives work on the buses
Isnt it strange how Pratt and Whitney got the twist the wrong way round.
But then I suppose Douglas had already realised that
I guess this was before all the British designers emigrated there after the war.
[Sorry...never considered for the DC7...as I grew up less than a mile from where ALL of the DC7's were built, and knew many of the folks involved (engineering project manager a close relative), the 4360 was never on the designers table.]
The following is quoted from World Encyclopedia of Aero Engines by Bill Gunston
“The Mighty R-4360 had already passed its first test by June 1942 and later in the year was qualified at the unprecedented rating of 3,000 HP.
By VJ day it had been qualified at 3,500 HP.
The last throw was the R-4360 compound, which went beyond 4,000 HP. The vital application was the DC-7 and Wright won because the Turbo Compound was lighter and simpler. “
Of course this is a British Book, and Bill Gunston is a respected (but British)writer , I do live several thousand miles for where both the engine and DC7 were built and most of my relatives work on the buses
Isnt it strange how Pratt and Whitney got the twist the wrong way round.
But then I suppose Douglas had already realised thatI guess this was before all the British designers emigrated there after the war.
For those of us brought up fooling around with auto engines the sleeve valve can be a bit of an enigma and what is interesting is how this apparent complexity can turn out, when done right, to be so reliable. It must be something to do with the lack of shock in the action and the relatively low acceleration of the parts.
It also has other advantages besides just the sheer size of the ports it allows, for instance the ability to renovate by just pulling and replacing the sleeve. Granted the high friction area between the sleeve and the block must make the power requirement for starting a bit of a nightmare.
Seems a bit surprising there is not at least one eccentric auto manufacturer out there building a sleeve valve engine instead of the four or even five valves per pot jobs that are around now.
It also has other advantages besides just the sheer size of the ports it allows, for instance the ability to renovate by just pulling and replacing the sleeve. Granted the high friction area between the sleeve and the block must make the power requirement for starting a bit of a nightmare.
Seems a bit surprising there is not at least one eccentric auto manufacturer out there building a sleeve valve engine instead of the four or even five valves per pot jobs that are around now.
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T shirt,
That's just the point, Pratt&Whitney designed it that way...the right way 'round, for the B36.
Used on the C124, B50 and some models of the P2V...was a basic military design engine. If you are ever in KSFO, take a ride down the 101 freeway to the Hiller Helicopter museum at the San Carlos airport.
There you can see a rotating cutaway of the 4360...lots of bits and pieces all flailing around in close formation....
That's just the point, Pratt&Whitney designed it that way...the right way 'round, for the B36.
Used on the C124, B50 and some models of the P2V...was a basic military design engine. If you are ever in KSFO, take a ride down the 101 freeway to the Hiller Helicopter museum at the San Carlos airport.
There you can see a rotating cutaway of the 4360...lots of bits and pieces all flailing around in close formation....
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411A
Ok now I think I've got it !!
Pratt and Whitney, desperate to get into the radial engine business built an engine for the B36 which was a pusher engine.
Then to get more business they got it put into the C124, The C119 and the P2V but no one told them these engines were pullers rather than pushers.
Pratt thought that all they had to do was change the prop the other way round and bingo.
They then found out the hard way that the front cylinders were now in the back and it all went downhill from there.
Fortunately by then the all the jet engine people emigrating from Europe went to work for them and they got into the jet engine business and the rest as they say is history !
Ok now I think I've got it !!
Pratt and Whitney, desperate to get into the radial engine business built an engine for the B36 which was a pusher engine.
Then to get more business they got it put into the C124, The C119 and the P2V but no one told them these engines were pullers rather than pushers.
Pratt thought that all they had to do was change the prop the other way round and bingo.
They then found out the hard way that the front cylinders were now in the back and it all went downhill from there.
Fortunately by then the all the jet engine people emigrating from Europe went to work for them and they got into the jet engine business and the rest as they say is history !
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Ummm....
GGTs ,
P&W were in the radial business way before the R-4360!
The R-985/1340/1830/2000/2800 all spring immediately to mind [altho introduction of the R-2000 may be a bit out in this context?]
G'day
GGTs ,
P&W were in the radial business way before the R-4360!
The R-985/1340/1830/2000/2800 all spring immediately to mind [altho introduction of the R-2000 may be a bit out in this context?]
G'day
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Tshirt,
Pratt&Whitney...desperate?
Ah, well no actually. The 4360 was used because it was available off the shelf, so to speak.
But on the other hand, the folks at General Electric (the American company) used their developmental talents with turbochargers, to lead the USA into the jet age. A rather joint British-American effort.
The Brits did indeed lead for awhile with turbo-shaft design.
The Dart and Tyne are two good examples.
But then Allison came along with the 501 series....superb.
Now there's history
Pratt&Whitney...desperate?
Ah, well no actually. The 4360 was used because it was available off the shelf, so to speak.
But on the other hand, the folks at General Electric (the American company) used their developmental talents with turbochargers, to lead the USA into the jet age. A rather joint British-American effort.
The Brits did indeed lead for awhile with turbo-shaft design.
The Dart and Tyne are two good examples.
But then Allison came along with the 501 series....superb.
Now there's history
My dad always reckons that the Hercules sleeve valve design was most reliable and that the sleeve crank spindle, although small, rarely caused problems.
He only had 4 engine failures during his flying career and it was bits of German metal imposing themselves on good Bristol engineering that were to blame!
The poppet valve is not an elegant engineering solution is it. Functional yes, functional but requiring "constant" attention also yes. Unfortunately it's always the cheap and cheerful solutions that bean counters go for not the long term savings that good engineering can offer but cost a bit more in development.
He only had 4 engine failures during his flying career and it was bits of German metal imposing themselves on good Bristol engineering that were to blame!
The poppet valve is not an elegant engineering solution is it. Functional yes, functional but requiring "constant" attention also yes. Unfortunately it's always the cheap and cheerful solutions that bean counters go for not the long term savings that good engineering can offer but cost a bit more in development.
Iconoclast
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Yeah, but what about.......?
To: Feather #3
Here is the complete listing of air cooled P&W Radial engines:
R-985
R-1340
R-1535
R-1830
R-2000
R-2180
R-2800
R-4360
R-1690
R-1860
R-2180A
Here is the complete listing of liquid cooled P&W reciprocating engines:
R-2060
H-2600
H-3130
The R-985/1340/1830/2000/2800 all spring immediately to mind [altho introduction of the R-2000 may be a bit out in this context?]
R-985
R-1340
R-1535
R-1830
R-2000
R-2180
R-2800
R-4360
R-1690
R-1860
R-2180A
Here is the complete listing of liquid cooled P&W reciprocating engines:
R-2060
H-2600
H-3130
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Lu, I think I've also seen references to R-1300, R-1590, and R-1820
Also an X-1800, but I think this may never have gone further than prototype stage, like the R-2060.
Did the H-2600 and H-3130 make it into production ?
Also an X-1800, but I think this may never have gone further than prototype stage, like the R-2060.
Did the H-2600 and H-3130 make it into production ?
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Gee Lu, I did say immediately!
Thanks for the encylopediac listing.
Given that my list was of the more common types [plus, of course, the R-4360], would you mind giving some aircraft types to which the more esoteric [eg -1535: Hughes Racer?] models were applied, please?
G'day
Thanks for the encylopediac listing.
Given that my list was of the more common types [plus, of course, the R-4360], would you mind giving some aircraft types to which the more esoteric [eg -1535: Hughes Racer?] models were applied, please?
G'day
Iconoclast
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I read it in a book.
My source of information was the Aeronautical Vestpocket Handbook published by United Technologies Pratt & Whitney. Although there is reference to which turbojet engines were installed on which aircraft there is no reference to what airframes the more esoteric engines were installed on. I do not know if any of the lesser-known engines reached production. There were a lot of experimental aircraft that never reached production and I can only assume that those engines were designed for installation on those aircraft.
I would suggest you reference Janes as they once published a handbook on all the worlds reciprocating engines both production and experimental and they may have referenced the aircraft that the engines were installed on.
I would suggest you reference Janes as they once published a handbook on all the worlds reciprocating engines both production and experimental and they may have referenced the aircraft that the engines were installed on.
Here's a few of the scarcer types.
The P&W R1535 was a 14 cylinder Twin Wasp used on the Boeing 247 and the Bristol Bolingbroke.
The R1690 was a 9 cylinder single row that came as a direct drive or geared version. The direct drive version was used on the Bellanca C27 and the Sikorsky S4, and the geared version on the Martin B12, the FW 200 and the Lockheed 14.
The R2000 was of course used on the DC-4/C-54 and the DHC4 Caribou. I've also flown an executive DC-3 that had the R2000's installed. Great airplane. It gave you a gross weight increase from 26,200 to 26,900 lbs. for the passenger version, the same as the R1830-94 equipped version.
The P&W R1535 was a 14 cylinder Twin Wasp used on the Boeing 247 and the Bristol Bolingbroke.
The R1690 was a 9 cylinder single row that came as a direct drive or geared version. The direct drive version was used on the Bellanca C27 and the Sikorsky S4, and the geared version on the Martin B12, the FW 200 and the Lockheed 14.
The R2000 was of course used on the DC-4/C-54 and the DHC4 Caribou. I've also flown an executive DC-3 that had the R2000's installed. Great airplane. It gave you a gross weight increase from 26,200 to 26,900 lbs. for the passenger version, the same as the R1830-94 equipped version.
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Even numbers are possible!
Even numbers are possible - you just have to know where to look . . . at two stroke engines for example.
Koenig made a very nice little 4 cylinder radial two stroke for aircraft - admittedly only 28HP but it is still a radial and it is a lovely smooth engine to fly with.
The reason that four stroke radials have odd numbers isn't to do with the which way to turn but with the natural vibration modes built up and re-inforced by power pulses.
ALL horizontally opposed twin 4 strokes are really not nice and to get one to run smoothly you have to either run a balance shaft or live counter-wieghts on the crank.
When you tack two together as a flat four its a bit better but to really get it smooth go for a flat 6 as the power pulses are then 120 deg apart and cancel each other rather than re-inforce.
The two stroke can get away with flat twins and radial fours because the number of power pulses is doubled.
And you don't have many problems with valve gear and oil loss on a 2 stroke because there ususally isn't any and if it stops spitting oil that's when the trouble starts.
And finally, not all radials use master/slave con-rods with offset pins giving eccentric slave motion to the crank shaft. There are engines that use slider/slipping slave con-rods but they are in the minority and it is the offset pins that people remember.
TTFN
Koenig made a very nice little 4 cylinder radial two stroke for aircraft - admittedly only 28HP but it is still a radial and it is a lovely smooth engine to fly with.
The reason that four stroke radials have odd numbers isn't to do with the which way to turn but with the natural vibration modes built up and re-inforced by power pulses.
ALL horizontally opposed twin 4 strokes are really not nice and to get one to run smoothly you have to either run a balance shaft or live counter-wieghts on the crank.
When you tack two together as a flat four its a bit better but to really get it smooth go for a flat 6 as the power pulses are then 120 deg apart and cancel each other rather than re-inforce.
The two stroke can get away with flat twins and radial fours because the number of power pulses is doubled.
And you don't have many problems with valve gear and oil loss on a 2 stroke because there ususally isn't any and if it stops spitting oil that's when the trouble starts.
And finally, not all radials use master/slave con-rods with offset pins giving eccentric slave motion to the crank shaft. There are engines that use slider/slipping slave con-rods but they are in the minority and it is the offset pins that people remember.
TTFN
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If anyone is interested I would be happy to copy and mail the six pages I have found in Flight of 16 February, 1939 entitled 'Sleeve-Valve Development', the story of the successful work of the Bristol Company: Mr. A.H.R. Fedden's R.Ae.S and I.A.E. paper. Drop me an email to [email protected]
...and I might add the nine pages published a few weeks later 'Rise of the Radial'..!
...and I might add the nine pages published a few weeks later 'Rise of the Radial'..!
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Even better is the chapter in "Fedden - The life of Sir Roy Fedden" by Bill Gunston, published by the RR Heritage trust.
The book is a worthy addition to the bookcase of anyone interested in sleeve valves and radial engines in general.
The RRHT have a web site which lists the books they publish:
in addition to those about cars there are plenty to interest the aviation engine enthusiast.
PS: ATB, not trying to steal the thunder from your very generous offer, only pointing out other options.
The book is a worthy addition to the bookcase of anyone interested in sleeve valves and radial engines in general.
The RRHT have a web site which lists the books they publish:
in addition to those about cars there are plenty to interest the aviation engine enthusiast.
PS: ATB, not trying to steal the thunder from your very generous offer, only pointing out other options.
Last edited by henry crun; 15th Feb 2003 at 05:06.
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No probs at all with that, Henry. I do feel, however, that original, unadulterated, magazine articles offer a certain charm in comparison to a book over which the author has perhaps had time to evaluate all the information and arguments available to date. Interestingly enough, Felden presented his paper to Rolls-Royce a few weeks later and was apparently inundated with questions.
cheers
Bluebottle
cheers
Bluebottle