GregP
Major
Hi Elvis,
MTOW is Maximum Takeoff Weight and has nothing whatsoever to do with engine power.
Most British flight reports I have seen were corrected to 95% takeoff weight because you can't take off and get to altitude for a test without burning some fuel. I have yet to see one corrected to 95% power setting, but I have an open mind there as I have not read all the British flight test reports.
The British Merlin flight test reports I have read mention M.S. Gear (Medium Supercharger) and F.S. Gear (Full Supercharger). These are just the two gear ratios available in a 2-speed supercharger. You take off and use M.S. gear until you reached about full throttle height (FTH), throttle back and shift to F.S. gear, and then climb until service ceiling. That's why the top speed graph has the two dogtooth areas of top speed. The max for both is full throttle height for the supercharger gear you are in at the time. When you get there, the speed starts to fall off until it becomes time to slow down and shift into the next gear. The speed increases with power until FTH again. Some engines allowed takeoff without supercharger engaged, and you then went to M.S. at some intermediate height and F.S. at the M.S. FTH height plus a bit.
METO is an American term meaning power is at "Maximum Except TakeOff." Not all engines had an METO power setting. It was usually set by cylinder head temperature on the test stand, and was then transferred to the pilot manuals as a chart.
Military power is maximum power at rated rpm without ADI. Sometimes WEP allowed elevated rpm above rated rpm. WEP Dry was max power at elevated rpm without ADI. WEP Wet was max power at elevated rpm with ADI.
The British radial used in the Sea Fury was a Bristol Centaurus. It made max power in M.S. gear (2,560 HP at 9.5 lbs boost and 2,700 rpm). In F.S. gear, max power was 2,300 HP at a higher altitude. The Centaurus had sleeve valves and could NOT handle extra rpm. The monkey-motion valve gear would fail if you got to 2,800 rpm. Ask any Centaurus owner. If you stayed within limits, it was almost bullet proof and made enough power for the aircraft to be quite sprightly. It was not very "hot-roddable" as it was at or near the limits of the design power in the Sea Fury. That is NOT a knock on the Centaurus. It was a solid, reliable radial and still is. It's just not going to win Reno, and that has nothing whatsoever to do with WW2 anyway.
The Wright R-3350 has it all over the Centaurus in ability to be hot-rodded for racing, but the Wright also blows up on a regular basis, so it lets you know that it doesn't LIKE to be hot-rodded. We're very close to the end of the R-3350 engines as they are out of available main bearings. Of course, if you HAVE some good mains, you're lucky and in like Flint. They are still overhaulable as long as you don't need mains. The Centaurus can't be hot-rodded but is solid and reliable, If I had a Sea Fury, I'd want a Centaurus, myself. I'll take solid, reliable power every time over the absolute max HP that might live and might not, and my wallet would thank me. I only know one guy who can hone Centaurus cylinders and make them round again, but they are technically still overhaulable, too. Ellsworth Getchell recently went through his and his Sea Fury is back flying. See below:
http://www.gkbgraphics.com/wp-content/uploads/2013/05/Sea-Fury.jpg
Regards, Greg
MTOW is Maximum Takeoff Weight and has nothing whatsoever to do with engine power.
Most British flight reports I have seen were corrected to 95% takeoff weight because you can't take off and get to altitude for a test without burning some fuel. I have yet to see one corrected to 95% power setting, but I have an open mind there as I have not read all the British flight test reports.
The British Merlin flight test reports I have read mention M.S. Gear (Medium Supercharger) and F.S. Gear (Full Supercharger). These are just the two gear ratios available in a 2-speed supercharger. You take off and use M.S. gear until you reached about full throttle height (FTH), throttle back and shift to F.S. gear, and then climb until service ceiling. That's why the top speed graph has the two dogtooth areas of top speed. The max for both is full throttle height for the supercharger gear you are in at the time. When you get there, the speed starts to fall off until it becomes time to slow down and shift into the next gear. The speed increases with power until FTH again. Some engines allowed takeoff without supercharger engaged, and you then went to M.S. at some intermediate height and F.S. at the M.S. FTH height plus a bit.
METO is an American term meaning power is at "Maximum Except TakeOff." Not all engines had an METO power setting. It was usually set by cylinder head temperature on the test stand, and was then transferred to the pilot manuals as a chart.
Military power is maximum power at rated rpm without ADI. Sometimes WEP allowed elevated rpm above rated rpm. WEP Dry was max power at elevated rpm without ADI. WEP Wet was max power at elevated rpm with ADI.
The British radial used in the Sea Fury was a Bristol Centaurus. It made max power in M.S. gear (2,560 HP at 9.5 lbs boost and 2,700 rpm). In F.S. gear, max power was 2,300 HP at a higher altitude. The Centaurus had sleeve valves and could NOT handle extra rpm. The monkey-motion valve gear would fail if you got to 2,800 rpm. Ask any Centaurus owner. If you stayed within limits, it was almost bullet proof and made enough power for the aircraft to be quite sprightly. It was not very "hot-roddable" as it was at or near the limits of the design power in the Sea Fury. That is NOT a knock on the Centaurus. It was a solid, reliable radial and still is. It's just not going to win Reno, and that has nothing whatsoever to do with WW2 anyway.
The Wright R-3350 has it all over the Centaurus in ability to be hot-rodded for racing, but the Wright also blows up on a regular basis, so it lets you know that it doesn't LIKE to be hot-rodded. We're very close to the end of the R-3350 engines as they are out of available main bearings. Of course, if you HAVE some good mains, you're lucky and in like Flint. They are still overhaulable as long as you don't need mains. The Centaurus can't be hot-rodded but is solid and reliable, If I had a Sea Fury, I'd want a Centaurus, myself. I'll take solid, reliable power every time over the absolute max HP that might live and might not, and my wallet would thank me. I only know one guy who can hone Centaurus cylinders and make them round again, but they are technically still overhaulable, too. Ellsworth Getchell recently went through his and his Sea Fury is back flying. See below:
http://www.gkbgraphics.com/wp-content/uploads/2013/05/Sea-Fury.jpg
Regards, Greg
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