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Post by bernardo on Jan 27, 2009 6:51:14 GMT -5
I post this only to settle a discussion I have with a friend.
We're arguing that the L-049A's and the L-1649A'S some models ahd flat tipped props when usind Pratt & whitney engines wheather turbo charges or turbojet. I know the YC121 had them being turbojet engines,
Can anyone clarify if other models had them?
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Post by Tom/CalClassic on Jan 27, 2009 10:16:40 GMT -5
Hi,
No 049's or 1649A's had P&W engines. There was only one P&W powered Connie of any type, and it was converted back to 3350's as I remember. The 2800's made it underpowered.
There were two major propeller manufacturers back then - Hamilton Standard and Curtiss. Ham Stans used hydraulics to change the prop pitch, Curtiss used an electric drive. Often both were available, and airlines would pick which one they wanted. They often had different prop blade and hub shapes.
When Pan American bought American Overseas, they replaced AOA's Curtiss props on their Stratocruisers with Hamilton Standards.
That said, there were cases where the engine or prop manufacturer didn't change, but the prop blades did. When airlines refitted older DC-6's with the later R-2800 CB-16 engines, they replaced the rounded tip prop blades with square tip versions to absorb the extra power. Same engine and prop manufacturers, just different versions.
Hope this helps,
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Post by ashaman on Jan 27, 2009 12:17:00 GMT -5
No 049's or 1649A's had P&W engines. There was only one P&W powered Connie of any type, and it was converted back to 3350's as I remember. The 2800's made it underpowered. We're talking about the L-049 that remained at Howard Hughes ( I guess as his personal plane) and which fuselage was later stretched to make the first L-1049? |
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Post by Tom/CalClassic on Jan 27, 2009 12:55:12 GMT -5
Hi,
Yes, I think that is the one.
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Post by bernardo on Jan 27, 2009 14:39:55 GMT -5
Thanks guys, this has been most helpful. I've tried searching the net for pictures, haven't found any, Can any one guide me to a link?
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Post by Tom/CalClassic on Jan 27, 2009 14:41:40 GMT -5
A picture of what? I don't know of any web pics of the P&W powered Connie...
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Post by bernardo on Jan 27, 2009 16:44:05 GMT -5
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Post by chris_c on Jan 28, 2009 13:15:48 GMT -5
Thanks for the link, one can never read too much on any Constellation.
As a Canadian I always felt deeply embarrassed by some of the knee-jerk copy produced by those who attempted to block the acquisition of ex CF-TGE by the Museum of Flight.
Chris
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Post by bernardo on Jan 30, 2009 18:45:59 GMT -5
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Post by ashaman on Jan 30, 2009 19:47:50 GMT -5
No 049's or 1649A's had P&W engines. There was only one P&W powered Connie of any type, and it was converted back to 3350's as I remember. The 2800's made it underpowered. We're talking about the L-049 that remained at Howard Hughes ( I guess as his personal plane) and which fuselage was later stretched to make the first L-1049? Hi, Yes, I think that is the one. Sorry for making a nuisance of myself, but the two following questions ( like all the unsolved questions I apply my mind on) really drill my brain from ear to ear, lately.  How could the only L-049 engined R-2800 be really underpowered if, going by all sources I can find, the first generation of R-3350 to be used on the production L-049 only gave 100 hp more apiece? Did 400 hp total more really make a so great a difference to tip the scale towards a back then still unstable powerplant?  That and; I've read on the same sources as above that the back then still new and temperamental R-3350 was preferred on the R-2800 to power the production L-049 because of both the fact that the R-3350 had been chosen to power the B-29 ( and as such, with the army's pressing, would have been brought to a rapid maturation), and the fact that the R-2800, although a more stable engine at the time, was both at the end of its evolution ( under the power's point of view) and was more fuel-thirsty ( the sources I found say the R-2800 drank up to 20% more fuel than the R-3350). Now, I ask, if the R-2800 was such a mess, how come that after the war its power ramped up to 2800 hp in some incarnations ( that yes, were less powerful than the Turbo Compound R-3350, but we're talking about the L-049 here) and was largely used on the DC6 and other planes? Seen its supposed serious drawbacks, wouldn't and shouldn't have this engine been declared obsolete and forgot?  As a lot of other things in life, those explanations I found do not really make sense. Surely those could not be the real reasons, seen the success the R-2800 had after the war. Had the Lockheed other reasons to prefer the R-3350 for the Connie? Can someone make light in the darkness of my mind? |
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Post by sunny9850 on Jan 30, 2009 23:28:22 GMT -5
This is what I get for engine variations and power on the Connies and the difference there is significant.
Lockheed C-69 / C-121 Constellation
L-049, L-1049, L-1649, C-69,
C-121, PO, R7V, WV Production
4 / Wright Cyclone R-3350 2200hp - 3400hp Radial 18 / Air / T.C.
4 / Pratt & Whitney Double Wasp R-2800 2000hp Radial 18 / Air
Stefan
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Post by ashaman on Jan 31, 2009 6:59:49 GMT -5
This is what I get for engine variations and power on the Connies and the difference there is significant. Lockheed C-69 / C-121 Constellation L-049, L-1049, L-1649, C-69, C-121, PO, R7V, WV Production 4 / Wright Cyclone R-3350 2200hp - 3400hp Radial 18 / Air / T.C. 4 / Pratt & Whitney Double Wasp R-2800 2000hp Radial 18 / Air Stefan Always going by what I found ( I wasn't there myself, only can read about it ), the engines that were to be mounted on the pre-war L-049 were four 2200hp R-3350 ( chosen powerplant for the production plane) or, as alternative, as many 2100hp R-2800, for those who didn't want to risk using a then still green series of engines. I do find strange the fact that the 2100hp R-2800 powered L-049 could be considered seriously underpowered if compared to a 2200hp R-3350. The difference between one ( 8800hp total) and the other ( 8400hp total), should not have made such a great difference to tilt the choice towards an engine that, even if it showed great promises, was still far from being reliable at the times. The difference of power could have been felt comparing the only R-2800 powered L-049 with the post-war production models L-649 and L-749, engined with four 2500hp R-3350, but by then the R-2800 had escalated to new powers itself and was being adopted with success on the DC6. This is why I feel that we weren't told everything on the matter. The 3250hp and 3400hp versions of the R-3350 ( Turbo Compound) would come later, after the war, to power the L-1049 and the Starliner, respectively and aren't an issue here. |
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Post by stansdds on Jan 31, 2009 7:34:23 GMT -5
I don't like to rely upon the Wikipedia for information, but I think the entry on the R-3350 is correct and complete. Wright continued to develop the R-3350 after its introduction and really pushed radial engine technology to its limits while Pratt & Whitney pretty much ceased developing radial engines after the R-4360 and focused on turbines. Check the Wiki entry for a detailed explanation of why the R-3350 produced so much power. en.wikipedia.org/wiki/Wright_R-3350 |
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Post by Maarten on Jan 31, 2009 8:50:29 GMT -5
Basically the post war R-2800 (military designation) or Double Wasp (civil designation) was a virtually new design. The majority of wartime R-2800's (as installed in the P-47, F4U, Black Widow, C-46, Tiger Cat, Bearcat etc.) were of the "B" Series. Many of them having been built under licence by Ford. From what I read in the brilliant book "R-2800 - Pratt & Whitney's Dependable Masterpiece" by Graham White, there was some difference in quality between the P&W engines and the Ford engines, the latter ones having given some considerable trouble when in use with the P-47's. Of course, by then the R-2800 wasn't built for the commercial market and there was no oil crisis. The taxpayer paid his money anyway.
By the end of the war, plans became very realistic to produce the Double Wasp for commercial purposes (Douglas DC-6, Martin 2-0-2 and Convair 110 and 240 were under development. Thus the "C" series followed by the "CA" and "CB" series were developed. Basically one could speak of an almost completely new design. Important improvement were: different construction of the crankcase (1 piece), crankshaft with different dampers, newly designed cylinder (new cooling ribs which gave much improved cooling), newly designed connecting rods, etcetera. Also the introduction of ADI (Anti Detonant Injection) provided considerable extra power as did the improved quality of fuel.
This made the (postwar) Double Wasp aka R-2800 one of the most reliable and economic piston engines.
The R-3350 Duplex Cyclone never gained that rate of reliability. Many problems the B-29 bombers suffered were related to the R-3350's and in fact did delay production of both the Boeing B-29 and Lockheed C-69. From what I learned years ago from a former KLM ground engineer who worked on the L-049, L-749 and L-1049C/E/G/H (Super) Connies, the R-3350 was a sensitive engine throughout its whole carreer, in particular the Turbocompound version.
BTW, engineer Frank Walker, who regarded the R-2800 aka Double Wasp as his baby, was convinced that there was more life in 'his' engine than the official maximum take-off power, and that the R-2800 could keep up with the R-4360 aka Wasp Major. When he heard that the R-4360 had reached 3,000 hp, Walker met that challange by using ADI and higher manifold pressure. Then he heard that the R-4360 reached a 3,500 hp. Walker increased the manifold pressure on his R-2800 to 140", used as much ADI as the engine could tolerate, and also reached 3,500 hp. Then, when he heard that the R-4360 had reached 3,800 hp, he reacted by running the R-2800 at 150" map and reached 3,800 hp too. That's where he decided it had been enough. Besides that, it would have been hard to explain to his superiors if the R-2800 would have gone bust in the test cell at 150" map and 3,800 hp. :-) Mind you, the most powerful Wright R-3350 Turbocompound (installed on the Lockheed SP-2H Neptune) produced 3,700 maximum take-off power (with ADI).
Source of this R-2800 vs R-4360 story: the brilliant book "R-2800 - Pratt & Whitney's Dependable Masterpiece" by Graham White. Highly recommended. He also wrote a similar great book about the R-4360!
Cheers,
Maarten
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Post by ashaman on Jan 31, 2009 10:44:29 GMT -5
So in the end, if I have understood it all enough, the post war R-2800 was a complete redesign of the pre-war one? This would make sense, finally. I have honestly no direct experience with either engine, but indeed, from reading around, the R-3350 had quite the solid fame to be quite fastidious, with of course the pre-war engines ( been greener) and the turbo-compound ones ( having the mixed blessing of sporting power recovery turbines to make them more powerful and way more complex) being the more "fussy" among them. Do not misunderstand, please, I am fascinated with both engines equally ( and not only the two of them, at that). I am not into the childish business of taking a loving on one(s) and despising the other(s), simply trying to understand correctly the truth of things here.  Sure thing is that the post war R-2800 being a complete new project loosely based on the old, and of this keeping the same name barring a change of revision number, it explains a lot of what wasn't said about the choice made on the Constellations before the war. Thanks for the explanation, it calmed the drilling curiosity to a bearable level. ;D |
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