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Sadly the "19" on that chart is just a plain old catastrophic error.In the table at the back, he claims it is "Based on best recorded power outputs during type or approval test..."
IIRC, the British type test was 100 hours, although only 10 hours was at full noise. I might have mixed up the civil and military. Either way it was meant to be a sustained test.
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Where do you GET this stuff? I know 5 or 6 people who own and fly them and they don't say anything close to what you are saying. Of course, most of them aren't flying them over 10,000 pounds. But ALL have talked with the guys who did, nd nobody ever said it was a death trap or close to one. It ea spitch-sensiotive at takeoff, but that doesn NOT equate to dangerous unless you are flying aerobatics in it and get it wrong.Except the ferocious torque of the Griffin would have made the P-51's already 'exciting' tendency to drop a wing and roll as it unstuck even more 'exciting' - it was a borderline dangerous plane until it got moving and gained enough control authority.
Actually, they didn't need such high boost pressures to make power.Did they ever actually do so really? And would a two stage supercharger be worth it aside from higher altitude performance? Sleeve valves didn't like large amounts of boost.
Actually, they didn't need such high boost pressures to make power.
Compare the boost-to-power requirements for the R/R Griffon and the Napier Sabre, both being nominally equivalent in 'swept volume'.
The higher volumetric efficiency of the sleeve valve system ensures that its fuel is converted to power (seen in higher fundamental metrics
such as BMEP/BSFC) due to less compressing of the fuel/air being necessary (& it also does not need 150 grade plus ADI for +20lb).
The strength of the Sabre can be seen in its ability to produce 'normal/climb' power for a period which lasts as long as the internal fuel,
which is also at higher power output than the Griffon (or R-2800) can manage - with all in their final production forms.
Sabre piston speed was not excessive at higher rpm (unlike the Jumo 213 - Fedden was incredulous - at 3,700rpm for it).
No, it was in the same general size class for engines, with almost equal swept volume ~36 litres, but capable of doing more with it.Sabre was oversquare, and had twice the number of pistons at roughly equal swept volume as the Griffon. Precisely to be able to reach high rpm without excessive piston speed. Not saying those aspects of the Sabre were a bad idea, but a very different design philosophy compared to the Griffon. It was also a couple hundred kg's heavier than the Griffon, so in effect in a different size class.
No, it was in the same general size class for engines, with almost equal swept volume ~36 litres, but capable of doing more with it.
On a power to weight basis, or fuel consumption for output basis, & for sustained power setting levels.
Yes ok, props tend to become an issue at well over 2,000hp - during this period,
and the 14ft unit rotated by the Sabre was big for a fighter.
Can you present a single piston engine powered - WWII fighter aircraft - with a bigger prop?
ADI? No, I meant 100/130 with ADI, didn't need 150 grade for +20lb.
Sabre piston speed was not excessive at higher rpm (unlike the Jumo 213 - Fedden was incredulous - at 3,700rpm for it).
As noted by the above member, swept volume was not what was propelling the aircraft.No, it was in the same general size class for engines, with almost equal swept volume ~36 litres, but capable of doing more with it.
On a power to weight basis, or fuel consumption for output basis, & for sustained power setting levels.
Just like many engines.ADI? No, I meant 100/130 with ADI, didn't need 150 grade for +20lb.
IIRC Fedden didn't design neither Sabre nor Jumo 213.
What Sabre was not good was power at higher altitudes, but that somehow ends swept under the rug when people talk about the Sabre as it was the next best thing after the sliced bread.
Thank you.Nope, but he was sent to Germany after the war to get a better picture of what the Germans had been up to. Don't know details, but presumably Fedden's comments mentioned are from that mission.
Posted it here before:Care to post some docs that show Sabre's boost with 100/130 + ADI?
Just like many engines.
Every R-2800C with just 100/130 can use 70'' with water injection.
Thank you.
I was trying to point out that Jumo 213 was doing it's job, Fedden approving or not.
Funnily enough, I don't think that Jumo 213 have had any advantages over the Sabre, power-wise.To be fair, I'm not sure anything is known about the reliability of the 213J (the prototype version running at up to 3700 rpm) in service use. The MPS is beyond anything else in use during WWII, so I guess some scepticity is warranted.
A pretty decent achievement on 87 octane fuel.Funnily enough, I don't think that Jumo 213 have had any advantages over the Sabre, power-wise.