enginehistory.org

[kmccutcheon]

proe emailed a question that I could not resist placing before participants on the AEHS bulletin board:

[rhavemann]

The Greatest Piston AC ever Built? OK! let me start it OFF....It was the
WRIGHT R-3350 TURBO compound..Why?? For air cooled engines ,Max power is limited by cooling fin area plus the E factor of the cylinder baffels this is how it made 3700 horse power take off. The cruise B.F.C. was the greatest thanks to the power recovery turbines ,with the help of fuel injection..
It was simple,big and tough.The W reduction gear was good to 4000 HP. The PW Wasp Major? Ask a North west Airline Mech. how simple a 4360was. Ever see a B-36 come home with out a prop feathered ? Not very often.Yes the 3350 took some time to get everthing resolved But many Connies made it across the north atlantic for years. and the Nam stories about the 3350 AD,s Are as good as the R-2800 stories.Why am I makeing The 3350 claim? Because the R3350 is Round.Big ,leaks oil ,makes smoke and I own two of them.They are a piece of history never to be repeated.
take it from an incurable ENGINE NUTT.

[kmccutcheon]

Harry Keiner, a consulting archivist with United Technologies (Pratt & Whitney), produced the following list of “Thirty Most Significant Aircraft Engine” back in 1983:

1. Manly-Baltzer (1902)
2. Wright Brothers (1903)
3. Lavasseur Antoinette (1906)
4. Gnome (1909)
5. Anzani (1910)
6. Hispano-Suiza (1915)
7. Mercedes (1915)
8. Napier Lion (1918)
9. Curtiss D-12 (1922)
10. Wright J-5 (1925)
11. Pratt & Whitney Wasp (1925)
12. de Havilland Gypsy (1927)
13. Continental A-40 (1931)
14. Pratt & Whitney Double Wasp (1939)
15. Rolls-Royce Merlin (1940)
16. Bristol Hercules VI (1942)
17. Whittle W.1 (1941)
18. Junkers Jumo 004 (1944)
19. General Electric J47 (1947)
20. Roll-Royce Dart (1948)
21. Pratt & Whitney J57 (1953)
22. General Electric J79 (1958)
23. Pratt & Whitney J58 (1960)
24. Pratt & Whitney JT8D (1963)
25. Pratt & Whitney of Canada PT6 (1963)
26. General Electric TF39 (CF6) (1967)
27. Rolls-Royce (Bristol) Pegasus (1969)
28. Garrett TFE731 (1972)
29. Pratt & Whitney F100 (1973)
30. Rolls-Royce (Bristol) Olympus 593 (1975)
_________________
Kimble D. McCutcheon

[szielinski]

How about the greatest reciprocating engine that ever FLEW ?
(That will rule out some of your favourite engines and mine, I know, Kim).

Obviously you are right about a long-winded discussion, but maybe a comparison matrix would be interesting to compile.

Something like:-
-power-to-weight ratio
-Weight of air consumed per hp developed
-Hp/unit displacement
-$ per hp developed (manufacturing only, not R&D)
-part count per cylinder
-length of operational service (in original air force/airline)
-TBO !
-plus all the usual maxima (output/cylinders/displacement/type/weight/etc)

[jschauer]

My choice would be the P&W 985/1340 series, it is still in common use, new parts are being made for it, it's a simple engine, and easy to work on... The largest, best radial, R-3350-26WD. The best small engine, C-65/75/85 by Continental.

[rhavemann]

Right on! but let us not for get MANs BEST FRIEND ...
The C-145 ..O-300 I sat behind several of these benign creations
for 20 years . And subject them to all kinds of stupid abuse .but they all ways brought me back home. I even did my own major over haul.
( must have been simple engine) However the family has a closet member
stay away from a GO-300 ...its main diet was eating cylinders...
BY the way, I did not have to get a bank loan$$$ to pay the parts bill for the C major..This makes my wife a fan..also.What he world needs is a
repeat product, at a automobile price...

[ckuhns]

I would like to nominate the family of small Continental flat four cylinder engines for this category. This would include the A-50 A-65 c-75 c-85 c-90 o-200 and the Io-240. Many people learned to fly behind an A-65 in the 1930s 40s and 50s. Many more people have learned to fly behind an o-200 since its introduction in the Cessna 150.I think your can go to about any general aviation airport in the US and find an airworthy O-200. I also beleive it is the fastest four cylinder engine in the world as the powerplant for Jon Sharp's NEMENIS.Rolls-Royce made the o-200 and put their name on the valve cover. Carl

[ljohnson]

I agree....the most useful engines have been the horizontal opposed Continentals and Lycomings...More than any others they have brought flight to most.

Best sounding is perhaps a more interesting and equally subjective contest.

Nominate Griffon.....

[rwahlgren]

R-2800 PW, and R-3350 TC should both get the vote. Main reason is they are still around and being used. Both have excellent records of service after they were refined. Low powered engines shouldn't be included, they never powered any major airframe in the big one nor are their TBO's anything special.
As far as the inlines (V12's) they always had and still do have very low
TBO's, I think its in the 600 to 800 hour range, where as the 2 I mentioned are much higher. Even the R-4360 had a higher TBO than the RR's do.

[klankenau]

Prior to the Gnome, "dependable" would not be a term generally thought of when referring to an aero engine. It's simplicity and dependability revolutionized the scene just in time for the Great War, following which aircraft became commonly accepted. When viewed in the context of it's time, it was a leap of great magnitude, even though the basic technology eventually lost out to more "modern" or conventional design thought.

[sithomas]

Asking what is the best engine is like asking what is the best sunset.
Allow me to break down the question into a few categories:

1. Which engine was the most technologically advanced compared to its rivals at the time is was type tested?

2. Which engine stayed in production the longest?

3. Which engine provided the largest percentage increase in power over its rivals at the time of type test? (Say take off power, but any power setting will do provided it is an apples to apples comparison) Stick to normal production engines, not racing specials.

4. Which engine could the the most abuse and still get the pilot (& crew) home


My WAGs would be:
1. Napier Sabre
2. Wright 1820 / M-25 / ASh-62
3. I am going to guess one of the Bristol Centaurus, the Armstrong Siddeley Leopard or the Wright R-2600.
4. Liquid cooled: Merlin / Air Cooled: R-2800

[avasko]

May I propose an odd choice?
As a licensed A&P starting in 1954 at what was the FBO of the then Idlewild Airport (KIDL) I worked a lot of different engines as we serviced many different carriers. Never did wok a R-4360 as they were limited only to a few big carriers. . Aside from school didn't work an R-1820 either.
Some engines were total pigs - the worst in my experience was the BA version of the R-3350 in L049 Constellations. It was filthy with leaks from the push rods which used the old hose and clamps to handle the cylinder growth. Its cylinder heads cracked and I have seen one that was cracked all the way around the barrel just above the hold-down ring. It hadn't come off because it was a rear cylinder and the Dynafocal mounts attached to the cylinder held it in place. If any part pf the power section was clean you immediately suspected an injection line pinhole leak. Wright had a thing for forward facing exhaust pots and so there they were feeding a big collector ring around the front. The rears exhausted aft but due to the Dynafocal engine mounts attached to the rear cylinder heads you couldn't get through.
They had a lot of engine failure too. But enough on that engine.
There was the R-1830 on the DC-3, the R-2000 on the DC-4, theR-2800 B series on the C-46 and the CA/CB engines on the DC-6.
The R-3350 BD series on the the L-749 Constellations was a different engine from its predecessor. The ones with jet stacks deposited a thick layer of gunk on the flame shields just aft protecting the nacelle. Mostly though a very good engine from a mech's view.
Then the 972TC18DA3, the turbo-compounded R-3350 on the L-1049 and the similar one on the DC-7. Cracked cylinder heads, an exhaust pipe system that took constant attention and see how you would like pulling a nbr. 2 power recovery turbine and, off with it being on the lower port side, released a flood of oil on you. The EA models were far better
So what's my choice for best engine? The humble P&W R-2000. It was the engine that beat the Atlantic Ocean on a regular basis. It made the trip routinely. It was the C-54 and its engines that made crossing the ocean a scheduled thing. It would go out of KIDL, fly to India, pick up a load of monkeys destined for Salk vaccine growth, come back five days after it left and nary a squawk in the log book on the engines. It didn't leak much oil, its ignition gave no problems. Only changing a prop governor was a pain as it was sandwiched between the mags and you had control cables to deal with. It just clunked with not much being asked of it (only 1450-hp on 2000-inches displacement) and I, at least, never saw one fail. It was a mature engine by the time I started working in them which accounted for much.
But my view is from an open engine cowling and different than what Kim started this post.

[kmccutcheon]

Great information, Tony. Yours is a perspective about which we hear little these days.
_________________
Kimble D. McCutcheon