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No time, talent or treasure wasted on the Rolls-Royce Crecy, Eagle and Pennine may encourage RR to move faster on the Rolls-Royce Derwent and Nene jets.For some, more or less palusible reason - say, the sleeves can't be manufactured in required strength and precision on the metalurgy of the day? - the engine companies decide by early 1930s that the sleeve valves are a blind alley. How much this change the 'scene', predominatly at Bristol and Napier? Gains vs. losses? Possible effects on ww2 design and production of both engines and related aircraft?
With no Sabre or Centaurus, which engine does Hawker use? Wait for the higher horsepower later versions of the Griffon? Without the above sleeve valve distractions (the Crecy first ran in April 1941) could Rolls Royce get the Vulture fixed for the Typhoon?Hawker Typhoon gets a different engine
License built engines from the states until the turbines come online. (A massive industry wide program failure involving sleeve-valves would have probably got Sir Wilfrid a bit agitated.)
If, as the original post states, the realization that the sleeve valve was a no-go in the early 30s (or even 35-36) there would have been time to develop british poppet valve engines without resorting to licencing US engines. If you wait until 1939 things are an awful lot tougher.
The Hyena was a non starter, 15 cylinders for 1615cu in is too expensive. trying for multiple rows of cylinders inline on an aircooled engine is asking for trouble. This is with hindsight.
The Deerhound had more potential but still had problems
View attachment 576063old machine press.
Trying to cool the rear row of cylinders was a major problem.
air-cooled engines with cam boxes on top of the cylinder heads may have problems in any case.
Napier disappears as an engine maker
No time, talent or treasure wasted on the Rolls-Royce Crecy, Eagle and Pennine may encourage RR to move faster on the Rolls-Royce Derwent and Nene jets.[/QUOTE]
The Eagle 22 and Pennine likely had no effect on the development of the Derwent and Nene. The Derwent was being developed at the same time as those two.
With no Sabre or Centaurus, which engine does Hawker use? Wait for the higher horsepower later versions of the Griffon? Without the above sleeve valve distractions (the Crecy first ran in April 1941) could Rolls Royce get the Vulture fixed for the Typhoon?
The Crecy was developed with a small engineering team.
The issue with fixing the Vulture was always going to be the effect on the development of the Griffon and, more importantly, the Merlin.
Without a Sabre (or Napier engine) you are left with the Tornado, powered by the Vulture.
The British save millions in R&D costs
Napier disappears as an engine maker
Hawker Typhoon gets a different engine, effect on the war is negligible.
Bristol changes to a two valve hemi head with valve gear lubricated by engine oil instead of grease guns.
Bristol makes a two row 14 cylinder radial using Mercury cylinders.
Bristol goes on to make an 18 cylinder two radial using cylinders with the same bore as the Mercury but a longer stroke.
Can't the Griffon do the heavy pulling? It's producing 2,400 hp in later variants, still short of the Sabre's 2,800 hp, but perhaps the Griffon can be developed further? As there's no replacement for displacement, an larger volume Griffon seems in order. Why go for 18-24 or more cylinders when you can go with twelve in a proven design?The Air Ministry would not allow that to happen.
More likely the Rapier/Dagger style engines would have led to a larger, liquid-cooled H-24. Possibly like the Sabre, but with poppet valves.
Alternatively they could have come up with a new Lion style engine, with 3 banks of 4 or 12 cylinders.
I think we need to start with the "plausible reason", otherwise this just becomes a contrarian turkey shoot with every proposed alternative to sleeve valves getting quickly rejected. We can see it already above; X makes a suggestion, Y says that's not going to work, then repeat.For some, more or less palusible reason - say, the sleeves can't be manufactured in required strength and precision on the metalurgy of the day? - the engine companies decide by early 1930s that the sleeve valves are a blind alley.
Certainly the Typhoon and Tempest were contributive, but does the Spitfire need a competitor? Instead I suggest total focus on developing and producing the Spitfire, and then move to the Meteor and Vampire.Without the Sabre or Centaurus, you'd be looking at the Vulture, R-2600 or R-2800. So imagine this, a fighter that you could operate anywhere in the World in WW2, a worthy successor to the Hurricane, a competitor to the Spitfire.
Rolls Royce felt that the cylinders in the Griffon were as large as practical due to flame travel limitations.Can't the Griffon do the heavy pulling? It's producing 2,400 hp in later variants, still short of the Sabre's 2,800 hp, but perhaps the Griffon can be developed further? As there's no replacement for displacement, an larger volume Griffon seems in order. Why go for 18-24 or more cylinders when you can go with twelve in a proven design?
I think we need to start with the "plausible reason", otherwise this just becomes a contrarian turkey shoot with every proposed alternative to sleeve valves getting quickly rejected. We can see it already above; X makes a suggestion, Y says that's not going to work, then repeat.
We can avoid this wacka-mole game if we have Tomo's reason why sleeve valves are rejected, since that's the technical challenge any new poppet-valve engines will be asked to address. We can't just say sleeve valves don't exist, since they've already been used throughout the 1910s, 20s and 30s in AFVs, tanks, automotive, agricultural and other applications.
We should acknowledge the frustrations below.... Sleeve valve - WikipediaThe Eagle 22 and Pennine likely had no effect on the development of the Derwent and Nene. The Derwent was being developed at the same time as those two.
Can't the Griffon do the heavy pulling? It's producing 2,400 hp in later variants, still short of the Sabre's 2,800 hp, but perhaps the Griffon can be developed further? As there's no replacement for displacement, an larger volume Griffon seems in order.
Why go for 18-24 or more cylinders when you can go with twelve in a proven design?
I think we need to start with the "plausible reason", otherwise this just becomes a contrarian turkey shoot with every proposed alternative to sleeve valves getting quickly rejected. We can see it already above; X makes a suggestion, Y says that's not going to work, then repeat.
We can avoid this wacka-mole game if we have Tomo's reason why sleeve valves are rejected, since that's the technical challenge any new poppet-valve engines will be asked to address. We can't just say sleeve valves don't exist, since they've already been used throughout the 1910s, 20s and 30s in AFVs, tanks, automotive, agricultural and other applications.