Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: DiabloTX on February 19, 2008, 12:15:48 AM

Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: DiabloTX on February 19, 2008, 12:15:48 AM: (http://www.wwiiaircraftperformance.org/150grade/p-47-66inch.jpg)

I'd say that the R-2800 was a fairly robust engine design.
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: Karnak on February 19, 2008, 12:35:10 AM: I've seen comments about R-2800s being run at WEP for 100 hours. I know Merlins were run at WEP for extended times too.
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: DiabloTX on February 19, 2008, 12:44:53 AM: WOW...I hadn't heard of that. Incredible...
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: Wolfala on February 19, 2008, 01:29:27 AM: Someone should send this doc over to Teledyne Continental and ask why 60 years later we can't have engines run at 130% of maximum for hours on end and need a top OH at 1000.
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: thrila on February 19, 2008, 01:34:13 AM: One thing that has always annoyed me in Il2 is the spits engine overheating in 5 minutes at full power. I cannot recall a single time i have ever read in any spitfire pilot's biography anyone being concerned about over-heating the engine in the spit.
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: MiloMorai on February 19, 2008, 01:38:56 AM: Quote
Originally posted by Wolfala
Someone should send this doc over to Teledyne Continental and ask why 60 years later we can't have engines run at 130% of maximum for hours on end and need a top OH at 1000.

What are the overhauls times for the 2000hp R2800s?
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: Wolfala on February 19, 2008, 01:58:13 AM: Depends how you ran them. (http://www.advancedpilot.com/images/basictheory.jpg)
(http://www.advancedpilot.com/images/aircraftengine.jpg)

Post war, it wasn't unusual to see R-2800s and Curtis Wright 3350s run to 3000 hours and beyond. The first book was originally published in 1957 as a collaborative effort between American Airlines, then operating the DC-7, and by Wright Aeronautical Division of the Curtiss-Wright company.

The second one was done in 1955 and is still taught at advanced engine monitoring classes. Of course, back in the 50s they didn't have multipoint monitoring systems - they had specialized gauges that by design of the radials actually allowed direct measurement of the actual power being delivered to the prop and specific leaning methods tailored toward that spearheaded by the airlines (Flying DC-7s and the sort). Radials gave a somewhat even distribution of air to the cylinders. With the Flat 4s and Flat 6's of today - with pleneum type intakes - we lost that.

The radials in service then - at least on the airline side were pretty much operated Lean of Peak all the time, before the term became reinvented by GAMI.

I'm sure Widewing would like to chime in on the operational side. I just speak from the mechanics wing.
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: Squire on February 19, 2008, 06:11:09 AM: The "5 minute" limits were for ensuring engines would last a certain # of combat hrs, almost all of them could run very hot, and overboosted for long periods, but your fighter wing could not be pulling engines every other flight when you had a war to fight, and win.

There was a memo from RAF Fighter Command during the BoB about pilots abusing the wep limits, and causing grief for the maintenace schedules. Not that I can't understand it, your up there in real life with your butt on the line, not just some game.
Title: Interesting document: R-2800-63 on WEP for 7.5 hours.
Post by: Gabriel on February 19, 2008, 08:35:37 AM: These late Piston era engines are pretty amazing overall, if you consider where they were not twenty years before in 1918/1919 or so.

Interesting reads thanks.