Moderators: richierich, ua900, hOMSaR

 
LH707330
Topic Author
Posts: 2308
Joined: Fri Jun 15, 2012 11:27 pm

PW4000-94 and CF6-80C2 Comparison

Wed May 06, 2020 3:02 am

The other thread about the DC10 engines and the 747 wing tank capacities got me thinking about the era of the "commodity engines," where every widebody frame had either 2, 3, or 4 of whatever the highest-thrust engine of the time was. In comparing the PW4000-94 and the CF6-80C2, I saw they have similar thrust, OPR, BPR, TSFC, and weight, but their layout is quite different. Compare here:

PW: 1F 4 LPC 11 HPC 2 HPT 4 LPT 153.6 in (390 cm)
GE: 1F 4 LPC 14 HPC 2 HPT 5 LPT length 168 in (427 cm)

Why is it that GE built so many more stages into their engine and made it so much longer in the process? It was obviously the best-selling engine of that generation, so they were doing something right, but what?

https://en.wikipedia.org/wiki/Pratt_%26_Whitney_PW4000
https://en.wikipedia.org/wiki/General_E ... 6#CF6-80C2
 
Wacker1000
Posts: 210
Joined: Tue Jan 07, 2014 6:36 pm

Re: PW4000-94 and CF6-80C2 Comparison

Wed May 06, 2020 12:09 pm

LH707330 wrote:
Why is it that GE built so many more stages into their engine and made it so much longer in the process? It was obviously the best-selling engine of that generation, so they were doing something right, but what?


Its what makes it the 4 time world discus throwing champion.
 
User avatar
747classic
Posts: 3017
Joined: Sat Aug 15, 2009 9:13 am

Re: PW4000-94 and CF6-80C2 Comparison

Wed May 06, 2020 1:59 pm

See this old thread : viewtopic.php?t=771335
Operating a twin over the ocean, you're always one engine failure from a total emergency.
 
LH707330
Topic Author
Posts: 2308
Joined: Fri Jun 15, 2012 11:27 pm

Re: PW4000-94 and CF6-80C2 Comparison

Wed May 06, 2020 11:47 pm

Wacker1000 wrote:
LH707330 wrote:
Why is it that GE built so many more stages into their engine and made it so much longer in the process? It was obviously the best-selling engine of that generation, so they were doing something right, but what?


Its what makes it the 4 time world discus throwing champion.

Ha ha, clever.

747classic wrote:
See this old thread : viewtopic.php?t=771335

Thanks for the link, that was a good read. The tl;dr of that seems to be that the GE gets better temp margins at high-thrust settings, marginally better TSFC at takeoff, and slower deterioration, but outside of that they seem pretty similar.
 
User avatar
747classic
Posts: 3017
Joined: Sat Aug 15, 2009 9:13 am

Re: PW4000-94 and CF6-80C2 Comparison

Fri May 08, 2020 6:00 am

I found this article (2017) about the maintenance facilities of the large civil engine OEM''s and MRO's.
A nice comparison between the numbers built of each engine type

Clearly visible is that PW is only No 3 in the wide body engine market , after GE and RR.
The battle between PW and GE seems to be lost by PW during the PW4000/CF6-80C2/E contest and finished off by GE with the introduction of the large GE90-94/110B/115 and the failure of the PW4098 engine.
RR became a good second, but now has serious issues with a large share of it's engines.

See : https://www.ajw-group.com/storage/downl ... mmerce.pdf
Operating a twin over the ocean, you're always one engine failure from a total emergency.
 
User avatar
767333ER
Posts: 1169
Joined: Wed Jun 15, 2016 5:14 am

Re: PW4000-94 and CF6-80C2 Comparison

Fri May 08, 2020 8:00 pm

Well the CF6 ended up being the most powerful of those level of engines and it also is louder than the PW4000-94 which makes sense. The most powerful engine in this case is simply the biggest one. The CF6 basically began as the CF6 and got changed here and there every time there was the need. The PW4000 as an evolution of the JT9D so its lineage is a little longer. A combination of this and the overall engineering goals would likely have lead to different sizes.
747classic wrote:
I found this article (2017) about the maintenance facilities of the large civil engine OEM''s and MRO's.
A nice comparison between the numbers built of each engine type

Clearly visible is that PW is only No 3 in the wide body engine market , after GE and RR.
The battle between PW and GE seems to be lost by PW during the PW4000/CF6-80C2/E contest and finished off by GE with the introduction of the large GE90-94/110B/115 and the failure of the PW4098 engine.
RR became a good second, but now has serious issues with a large share of it's engines.

See : https://www.ajw-group.com/storage/downl ... mmerce.pdf

The battle was somewhat lost looking at the PW4000-94 vs the CF6-80C2, but both were vastly more capable engines than the RB211 at that point which is why the RB211 failed to sell on many 767s and was not offered on the 747-400ER. PW had an opportunity to build on their moderate success there but they squandered it. Then RR came out with the Trent and PW could not secure a second place.
Been on: 732 733 734 73G 738 752 763 A319 A320 A321 CRJ CR7 CRA/CR9 E145 E175 E190 F28 MD-82 MD-83 C172R C172S P2006T PA-28-180

2 ears for spatial hearing, 2 eyes for depth perception, 2 ears for balance... How did Boeing think 1 sensor was good enough?!
 
LH707330
Topic Author
Posts: 2308
Joined: Fri Jun 15, 2012 11:27 pm

Re: PW4000-94 and CF6-80C2 Comparison

Fri May 08, 2020 11:15 pm

767333ER wrote:
Well the CF6 ended up being the most powerful of those level of engines and it also is louder than the PW4000-94 which makes sense. The most powerful engine in this case is simply the biggest one. The CF6 basically began as the CF6 and got changed here and there every time there was the need. The PW4000 as an evolution of the JT9D so its lineage is a little longer. A combination of this and the overall engineering goals would likely have lead to different sizes.
747classic wrote:
I found this article (2017) about the maintenance facilities of the large civil engine OEM''s and MRO's.
A nice comparison between the numbers built of each engine type

Clearly visible is that PW is only No 3 in the wide body engine market , after GE and RR.
The battle between PW and GE seems to be lost by PW during the PW4000/CF6-80C2/E contest and finished off by GE with the introduction of the large GE90-94/110B/115 and the failure of the PW4098 engine.
RR became a good second, but now has serious issues with a large share of it's engines.

See : https://www.ajw-group.com/storage/downl ... mmerce.pdf

The battle was somewhat lost looking at the PW4000-94 vs the CF6-80C2, but both were vastly more capable engines than the RB211 at that point which is why the RB211 failed to sell on many 767s and was not offered on the 747-400ER. PW had an opportunity to build on their moderate success there but they squandered it. Then RR came out with the Trent and PW could not secure a second place.

Yeah, the 211-524G/H was definitely the worst of that generation: it was heavier and burned more fuel. PW and GE definitely sharpened their pencils relative to the earlier generation, where it seems the 524D was the high point. I'm wondering how exactly PW managed to drop the ball on the 4000-94, maybe it was the support area where buyers of the JT9D got frustrated. Several longtime PW buyers defected to GE on that generation, like ANA and JAL. Then you have oddballs like Delta who bought CF6-80As, then PW4000-94, then CF6-80C2 on their 767s....

Who is online

Users browsing this forum: 747classic, Hosta and 31 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos