Sound of Wright vs Pratt Whitney (Super Constellation vs. DC4)

[b377]

Ok, this one will bring tears to the vintage flyers amoung you with memories and a soft spot for pistons ...

As I mentioned in an other thread I grew up in the flight approach path of BOG El Dorado. To say that the sound of a Super Constellation flying over head was distrinctive is an under statement when comparied to the sound of a DC4 or even a DC6. Also to see the Super Constellation at fly over at night with all four exhaust stacks on fire ...

My father once said that the difference was due to the Wright engines on the Connie having synchronised firing making for a more uniform and smoother sound.

Not sure about the DC7 which also had Wrights.

I wish I could remember the sound of the Stratocruiser's P&W Wasp Mayor corn cobs whether they were synchronised and if they therefore sounded similar to the Connie. Something tells me the were but ...

I could also easily tell between a Curtis Commando ( C46) and a DC3 without stepping outside to look.

[DC-ATE]

b377 -
Ok, this one will bring tears to the vintage flyers amoung you with memories and a soft spot for pistons ...


Tears is right! Only time I get to hear those sounds now is on my Flight Sim.

Of course the Connie had different engines: R-3350 w/o PRTs and R-3350 w/PRTs. Different sounds. But, you mentioned the Supers and they all had the 3350s with PRTs. The "fire" had a lot to do with mixture settings.

All the DC-7s had the 3350s with PRTs. But exhaust stack design has a lot to do with the sound as well. The Convair 340s (R-2800s) with augmenter tubes sounded different from the DC-6s with the same engine.
The R-4360s (corn cobs) were something else!

As to the C-46 vs the DC-3; again two different engines.

Ahh.....the good ol' days.

[dixi188]

Big radial engines.

Not sure if every one knows, (I only discovered recently) that the model number is the capacity of the cylinders in cubic inches.

Wonderful sound.

There's a DC-6 flying in the UK still.

[Feather #3]

The PRT's mute the exhaust of the R-3350 on the L1049, as distinct from the "pure" exhaust of other round engines.

Now, for a great note, you can't beat the augmented exhaust of the R-2000 on the DHC-4 Caribou!!:D

G'day ;)

[DC-ATE]

Feather #3 -
The PRT's mute the exhaust of the R-3350 on the L1049

Actually, the L-1049 did NOT have PRTs. There were on the 1049C and subsequent models. The 1049s had 'straight' 3350s and were quite loud.

[airfoilmod]

Four rows of seven with a turbo supercharger that pumped the intakes and drove the crankshaft through an impellor, gear thing. The flame(s) were invariably white, and provoked interesting reactions from some pax.
"Sound" does it insufficient justice.

[stepwilk]

The Wright 3350 was two rows of nine. I've flown them.

Stephan Wilkinson

[DC-ATE]

Not only two rows of nine, but the ones with PRTs had THREE turbo blowers.

Four rows of seven relates to the 4360s.

[Old Fella]

For those who do not know, a PRT is a Power Recovery Turbine and it is not a "blower". The three PRT's are driven by exhaust gasses and used the power generated to increase horsepower. Vertical shafts driving onto the crankshaft via bevel gearing transmitted the added power. In at least one instance I know of, in about February 1959, an uncontained PRT failure started a fire which brought down a RAAF P2-V5 (P@-V5) Neptune, with the loss of 10 crew, when the wing spar burnt through. The wing failed on finals to the short grass runway at RAAF Richmond, the aircraft impacting into the eastern bank of the Hawkesbury River a couple of miles short of the airfield. It was not a pretty sight.

[411A]

an uncontained PRT failure started a fire...

Same thing brought down a Northwest DC7 just north of Manila, as I recall.
When the PRT failed, it would initially torch out the exhaust stack, big time, and would be noticed by an approximate 20 BMEP decrease on the affected engine.
Shutdown, right now.

The CurtisWright turbocompound engine was a paragon of efficiency, but somewhat unreliable in service.

[b377]

Ok that was something I did not know that the PRT was partly responsible for the different sound, which sounds very plausible indeed.

Two things outstanding:

- What about synchronised firing of all cylinders in the four Wright engines on the L1049 vs. free running P&W on DC4/6?

- Can any one elucidate on the sound of the corn cobs? These did not have a PRT but super chargers and 27 pistons each. Do the C97s still flying sound like the old Stratocruiser?


I was once told that the sweet, tuneful, friendly sound of the DC3 was in part due to shape & inner structure of the wings (resonance) ...

[BelArgUSA]

b377 - yessir...
xxx
R-4360 on the B-377 (C-97) were same engine/same power, sounded same.
My ear cannot recall the thunder of the 3500 hp these made.
28 cylinders, 56 spark plugs per engine...
My mother took me from Brussels to London early 1950s, a PanAm B-377.
I recall playing with a model toy plane, on the stairs to the bar in the tail.
Got a "diploma" signed by the captain, aircraft was N1029V.
xxx
Van Nuys, early 1970s... American Jet (Alan Paulson's facility).
There was an old Guppy stored there, I went inside... to cockpit...
Sat in the captain seat, some old instruments were left.
And there was a N registry small plastic plate on the pilot panel... N1029V...!
Took my Swiss army knife, and yanked-it... incredible souvenir.
Sadly, when I moved to Argentina 1993, lost a lot of my memorabilia...
xxx
:8
Happy contrails

[b377]

Golly BelArg !

Ditto

BOAC Strat, March 1958 NY - LDN
then BOAC Strat, April 1958 LDN- Kingston ( to connect Avianca L-1049 service to Barranquilla)

My mother sent me to rescue my father from bar lounge below after a few too many G&Ts . I recall ( at 4.3 years old) looking up thru lounge window at horizontal stabiliser which seemed miles above.

Alas got no souvenirs only a post card that said BOAC Stratocruiser Speed Bird RMA Cordilia. Landed Heathrow North Terminal - now Terminal 3 I think.

To think that not a single B377 was preserved !!

[Old Fella]

b337 Don't mean to be picky, but the "corn cob" engine had 4 rows of seven = 28 cylinders. Propellers have a bigger influence on the sound you hear than many people appreciate. That said, the sound of a Pratt & Whitney R-4360 Wasp Major at full chat sure is unique.

[werbil]

Whilst I don't get to play with the big round engines, I do get a lot of pleasure from the Wasp Junior (P & W R985). If the sound of a single 985 flying over a few feet above me on a still day in open water is anything to go by the tone of the multi row engines must be incredible.

Whilst radials may not be as reliable as turbines, listening and feeling the regular beat is very reassuring offshore.

[b377]

:)Thanks Old Fella

7 x 4 = my slide rule is past it

Corn cobs must have been very smooth engines with such number of pistons reciprocating .. all 112 of them.

I really regret not having a museum worthy Stratocuiser to behold in persona - a fallen queen, a Lady with a Past or what ever as explained by EK Gann in this Flying Circus but nevertheless the most unique airplane that ever flew.

[b377]

That said, the sound of a Pratt & Whitney R-4360 Wasp Major at full chat sure is unique.

Boy, I wish someone could impersonate a quartet of WMs for me ! I hope the C97s are kept flying until I get a chance to get near one.


Any of you guys flying a C97? Remember to tell me if bringing one to the UK. Any one ever recorded a C97 on CD?

[Spooky 2]

I guess I'm fortunet as I flew the L1049H,DC6B/DC7C in airline service along with the C97 while in the Calif. ANG. Each of these aircraft had their own unique personality and unfortunely the R4360 and the R3350 both left something to be desired regarding reliability. Of the three, the R2800 was cerainly the most dependable powerplant. At the end of the Vetnam war, the Air Force would not let the C97 into the various air bases within Vietnam simply because they would breakdown and take up valuable ramp space that was needed for the C141 and C130. We would off load in Guam and they would put the cargo on either a 141 or 130 for the in country leg.

[b377]

Spooky

How did the C97 sound compare with the other planes you flew? L1049,DC6/7 etc

[BelArgUSA]

When I joined PanAm, had a lot of captains ex-377, DC-6/7 drivers.
So, had a lot of questions to them.
xxx
"Captain Joe, how do you recognize a DC-6 from a DC-7...?"
"On the ground, I know, 3 blades versus 4 blades... but...?"
And the answer was...
"Son, if a plane is landing with one feathered, must be a DC-7..."
xxx
:}
Happy contrails

[Spooky 2]

Well it's been so long now that simply cannot recall the differences. Keep in mind that what an engine sounds like inside the aircraft vs outside is quite different...thank God.

[JohnFTEng]

For the uninitiated or those simply wanting to recall the sounds you can find some examples at AEHS Home (http://www.enginehistory.org) and look for the "sounds" tab on LHS. Theres lot of details about the engines as well.

[DC-ATE]

Old Fella -
For those who do not know, a PRT is a Power Recovery Turbine and it is not a "blower".

Yes, I'm aware of that. Not sure why I referred to it as a 'blower' in that post. I've sat between enough of those PRTs to know. They DO blow though.:8

-----
411A -
The CurtisWright turbocompound engine was a paragon of efficiency, but somewhat unreliable in service.

Many times that depended on how each company operated their 3350s. Those that went by Wright's manual normally did alright. Those that came up with their own power settings for whatever reason, sometimes did not fair so well. I flew the Shuttle in the Connies and we had a nice low power setting (short segments) and I think those things went 3000 hours TBO.

-----
You 4360 lovers: go to You Tube and do a search on the B-36. The one with the clip from the movie Strategic Air Command with Jimmy Stewart has a good sound clip of one taking off.

-----
Spooky 2 -
I guess I'm fortunet as I flew the L1049H,DC6B/DC7C in airline service along with the C97 while in the Calif.

Me too almost, except the C97 as Passenger only. Didn't fly the -7C, but close; the -7B. Didn't fly the 1049H, but the 1049, 1049C, and G models. Great machines. Didn't get rated in the Connie, but did in the DC-6/7.

[JW411]

I was born just about 400 yards (metres) north of the main 31/13 runway at Prestwick airport nearly 68 years ago. You might say that I was heavily into aeroplanes for as long as I can remember.

The civilian aircraft in use when I was a youngster were DC-3s, DC-4s, DC-6s and DC-7s from the Douglas stable. L049, L749 and L1049 from Lockheed and the B377 Stratocruiser from Boeings. The odd Liberator, Languedoc, C-46 and even a Fokker XXII went by occasionally.

The USAF supplied such aircraft as the B-17, B-29, B-50, B-36, C-47, C-54, C-74, C-82, C-97, C-118, C-119 and C-124. The US Navy provided P2V Neptunes and the odd Martin Mercator.

There were many others.

To get back to the thread, I could lie in bed at night and identify most of them with quite a degree of reliability just by listening to the engine noise.

I slept very well despite the noise. In fact it wasn't noise to me but music. Only two things would wake me; the first was an unusual noise and the second was the Grumman Albatross with which 67th ARS was equipped. That aeroplane made so much noise that it could wake the dead 200 nms away. If I remember correctly, the engine was un-geared so the prop tips were supersonic (like the T-6/Harvard).

Isn't nostalgia a wonderful thing?

[b377]

was born just about 400 yards (metres) north of the main 31/13 runway at Prestwick airport nearly 68 years ago.


JW411

You must have seen quite a few Strats as Prestwick was a must stop for BOAC & PanAm oceanic flights. You must also have memory of the G-ALSA Christmas Day 1954 incident then.

[jwagsfarm]

I've enjoyed your threads on Wasp Majors. I need your help, to the dismay of my wife, I now have one in my garage I'm working to get running. It is complete but without a prop. My best guess is that by inspection of the cowl brackets it was last on a Boeing 377. This engine was last used by P&W for generating wind gusts for turbine engine testing where I work. It last ran about twenty years a go. I've rebuilt the starter and fuel pump, diassembled the carb and ordered some diaphrams to start reassembly, replaced one of the Scintilla mags. And even though Graham White's book is a lot of help and I do have access to the P&W archives I still have some questions. I'm hoping this group will be able to help too.
Is there a port that shows when the engine is at TDC for A1 so I can check mag timing?
Is there a way to peek inside the mag gear case and prop gear case to check things out in there?
What pressure should I set the fuel pump at?
There are four ~1" connections to the intake manifold just in front of the carb at the top of the engine, where to these go or what are they used for?
Where is the best place to connect my fuel, oil and manifold gages?
What is the minimum oil tank size to run the engine for 5 minutes or so?
Do I have to get the mil spec oil?
How much fuel will it burn? Is 97 octane ok or do I have to get av gas?
What boost voltage do I need to energize the mags for spark at startup?
Does anyone know where there might be a club prop or ground damaged props I could cut down to install?
Does anyone know where an engine test stand might be located to save me from building a sturdier stand than what I have now?
What should I be checking for in the oil sump?
Well, there you have it. There are lots more questions but have run out right now. Any help you guys can provide will be appreciated.

[DC-ATE]

Maybe you can get hold of this guy for some answers.

YouTube - Pratt and Whitney R-4360 - Run October 2, 2008 Penngrove, CA (http://www.youtube.com/watch?v=3gQ_HlxG23s)

There's a couple of videos on there where they don't use a prop at all?!?!

[fedex727]

Grin producing sights and sounds out here again today. Beautifully restored Harvard doing lazy aerobatics over the beach, orange and silver paintwork bright against the grey overcast. Definitely a distinctive noise compared to the usual Tomahawks and Warriors. :)

[b377]

Couldn't have been run for long or at high rpm without a cooling airflow.
Wonder if it had an oil radiator to help out.

[barit1]

...last used by P&W for generating wind gusts for turbine engine testing where I work.

I visited P&W on the occasion of their 50th anniversary open house (10/76) and saw that rig; The 4360 was mounted on a flatbed trailer, had a cut-down HS prop, and an exhaust stack that looked like a half-dozen oil drums welded end-to-end to divert the exhaust away from the inlet of the engine being tested. (I believe the test engine was the JT10D, sort of a predecessor of the V2500)

Just for a kick, you might check around on Ebay for tooling and test hardware - maybe even a prop.

If New England Air Museum (formerly Bradley Air Museum) is still around, they might have a lead on a prop.

[jwagsfarm]

I'll get over there and see what they might have for frame hardware and prop. I stopped there about a year ago when I got the engine but it was a bad time for them. As I'm getting closer to start up, I'll stop in a again and let them know my progress and plan. I started a blog on blog.com called Joel's R4360 Radial Engine. I've been putting updates and pictures there if you are interested.

[captjns]

There was nothing more beautiful to the eyes, ears, nose, and butt when awakening my P&W R985 just after first light. The air was crisp, the water would be like glass with a hint of mist hugging the water.


It was as if each cylinder would wake up until all 9 cylinders were firing, but still struggling to come to life. After the motor is warm and increase power all 9 are singing such a sweet song.

DeHavilland DHC-2 Beaver (http://www.bush-planes.com/DeHavilland-DHC-2-Beaver.html)

[JW411]

b377:

I do apologise but I have only just found your reply. It would be fair to say that I saw and heard a lot of Stratocruisers in my younger days at Prestwick. I can just remember those of AOA (American Overseas Airlines) before they became part of Pan American.

The Stratocruisers of Pan American and BOAC visited on a daily basis. I do remember vividly getting up on Christmas Day 1954 and seeing the plume of black smoke coming from the wreckage of G-ALSA (I have mentioned this on pprune before).

Of course, the USAF provided lots and lots of C-97s and KC-97s also. The earliest that I recorded was a YC-97 45-59589 (with the B-29 short fin and rudder) and the most advanced was the turboprop YC-97J 52-2693.

[dduxbury310]

JW411 wonders if the Wright Cyclones (R-1820-76) as fitted to the USAF's SA-16 Albatross amphibians were direct drive - they were not. According to tables of American aero engine specifications, the -76A and -76B (standard for the SA-16) had 3:2 reduction gearing. However there were ungeared versions of the R-1820 available (which I was previously unaware of) and listed in these tables, including the R1820-50 and the -103 series. Not certain of their particular applications.
David D