"No sleeve-valve engines" scenarios

[tomo pauk]

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?

 

[Shortround6]

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.

 

[Admiral Beez]

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?

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.

Hawker Typhoon gets a different engine

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?

 

[jetcal1]

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.)

 

[Shortround6]

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.

 

[jetcal1]

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.

Didn't the Hercules have problems between 1936 and 1939?

 

[swampyankee]

It's not like sleeve valves were the only route to high power engines. While a lot of manufacturers tried sleeve valves in automobiles (Knight produced sleeve valve engined cars starting in 1906) and the single sleeve (Burt-McCollum) dates from 1911. Continental developed -- and abandoned -- sleeve valve aircraft engines (Burt-McCollum type single sleeve valves) in the 1920s.

Net effect? Since everybody else was able to manage high powers and high power densities without sleeve valves, there's no reason to conclude that the UK wouldn't. After all, the US, Germany, France, Italy, Japan, and the USSR managed to produce successful aircraft engines with poppet valves. The only sleeve valve engine Napier produced was the Sabre. Bristol, more than any other company, had followed the path of sleeve valves. They, more than any other company, would need to change path. Of course, it's also not unheard of for companies to follow blind alleys into oblivion.

 

[Shortround6]

I am not sure the Hercules had any more problems than many other engines in it's first few years. Open to correction.
However the problems really started when they tried to mass produce it (and/or the Taurus/Perseus) as they couldn't keep the sleeves round and some were crapping out after 20 hours?
The hand built prototypes and low production Perseus engines didn't show the problem.
Oil consumption went up and plugs fouled. On occasion the sleeve jammed and the sleeve drive mechanism broke.
A major crisis in the making.

 

[Admiral Beez]

If Bristol's sleeve valve venture fails or is a non-starter, are there other British firms that can compete with radial engines, such as Armstrong Siddeley? Their 600 hp Hyena and 1,100 hp Deerhound have potential. Pobjoy would need to seriously increase their engine size to compete.

 

[Shortround6]

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

old 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.

 

[wuzak]

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.

The rear cylinder cooling issue was solved b reverse flow cooling.

The picture shown there is of the reverse cooling model. Hence the big scoop below the spinner, directing air to the rear of the engine.

 

[wuzak]

Napier disappears as an engine maker

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.

 

[wuzak]

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.

 

[Kevin J]

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.

 

[tomo pauk]

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.

The Mercury-related 14 cyl radial (~39 liters) might indeed be a good starting point.
On 87 oct fuel and low-level-supercharged, Mercury was making 870 HP at 4500 ft, or around 97 HP/cylinder. With 14 cylinders, it means 1353 HP, not far away from what early Hercules did. On 100 oct fuel, the highly-supercharged Mercury was doing ~950 HP at 8500 HP (some charts show up to 990 HP there). Going conservative, this will give ~1480 HP at 8500 HP. Or, 840/9*14= 1300 HP at 14500 ft on 87 oct fuel.
So all in all, Bristol might be producing a very useful 'classic' radial in good numbers well before ww2 starts, with power vs. altitude vs. availability combination 'moved' earlier by perhaps 6+ months vs. the historical Hercules.
Aircraft that might benefit from an early powerful radial include the Battle, Defiant, Hurricane, Beaufort, Beaufighter (no need for the Merlin-powerd version that was not liked), Whitley, Hampden, Wellington, Stirling, and the early Halifax (gets a radial instead of Merlin). Then, Albacore, Barracuda.
The much-improved series, akin to the Hercules 100, might be in service by early 1944 instead of late 1944.

The long stroke Mercury = roughly, Pegasus? On 87 oct, it is about 1000 HP down low; times 2 = 2000 HP (57.4 liters). Nice. On 100 oct, a bit more.
For Tornado, later Tempest, Sea Fury. post-war transports and civil aircraft. Perhaps Beaufighter as an upgrade?

Any reason for a smaller 14 cyl engine, 30 liters?

 

[Admiral Beez]

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.

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?

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.

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.

 

[Admiral Beez]

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.

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.

 

[Reluctant Poster]

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.

Rolls Royce felt that the cylinders in the Griffon were as large as practical due to flame travel limitations.

 

[Admiral Beez]

Three careers that may take different paths are Sirs Harry Ricardo, Henry Tizard, and Roy Fedden, the early champions of aeronautical sleeve valve engines.

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.

We should acknowledge the frustrations below.... Sleeve valve - Wikipedia

"Ricardo was constantly frustrated during the war with Rolls-Royce's (RR) efforts. Hives & RR were very much focused on their Merlin, Griffon then Eagle and finally Whittle's jets, which all had a clearly defined production purpose. Ricardo and Tizard eventually realized that the Crecy would never get the development attention it deserved unless it was specified for installation in a particular aircraft but by 1945, their "Spitfire on steroids" concept of a rapidly climbing interceptor powered by the lightweight Crecy engine had become an aircraft without a purpose."

 

[wuzak]

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.

The Griffon design was started 3 or 4 years after the Sabre, and would not have been available with the power required for an aircraft the size of the Typhoon/Tornado for it to be a useful aircraft.

Why go for 18-24 or more cylinders when you can go with twelve in a proven design?

The H-24 is two H-12s sandwiched together, so no real great problems there. The key would be building it as a single engine, rather than just using two of everything.

Rolls-Royce did propose an H-24 Merlin - using 4 Merlin Cylinder banks and two Merlin 61 superchargers, including intercoolers. It was set up so each half could run independently, like the Fairey P.24 was.

Foregoing the independent operation of each half would simplify the design, make it more reliable and lighter.

An H-24 based on the Merlin III would have ~2,000hp at +6psi boost and ~2,600hp @ +12psi boost, providing it could be made to work together.

Basically, more cylinders allows you to make more power.

Additionally, Napier had already built two small, air-cooled engines H-engines - the Napier Rapier (H-16) and Dagger (H-24). Both were designed by Major Frank Halford, as was the Sabre. If the sleeve valve was a no-go (I believe he was a fan), it is logical to suspect that Halford would have designed a liquid-cooled H-16 or H-24 of a similar size to the Sabre. The target power (2,000hp when the Merlin was 1,000hp) woudl have required that approach.

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.

Production of the sleeves and bores for reliable operation and not excessive oil usage a good enough reason? That problem plagued Bristol for years and had defeated Napiers before Bristol was ordered to help.