So who is making 1500+hp piston aircraft engines these days? They were all rendered obsolete by the invention of the Gas Turbine. That's not being a dead end, It's falling victim to a paradigm shift in technology.
Sir John Valentine Carden survives.
- Thread starter allanpcameron
- Start date
- Status
In fairness I was comparing the shittiest, most trouble prone Sleeve valve engine in production in the UK at the time to the shittiest, most trouble prone radial in production in the US at the time, and the sleeve valve engine still came out well.
All large aero engines are a technological dead end by the end of the war, the sleeve valve Bristol engines lasted as long in use as the well sorted Wright R3350 did in post war use so I don't see how poppet valves in large high horsepower engines have a massive benefit in the time frame we are talking about.
I'm not a sleeve valve fanboi by the way, and I agree completely that there is no use for sleeve vales now but technology moved on from the small window when sleeve valves were viable in these high horsepower engines.
The simplicity and cheapness of the poppet valve in post war internal combustion engines applications is well proven and unarguable.
I understand how a 2 stroke works, I also fully appreciate the sound a 12-71 or 16-71 makes but there isn't a two stroke diesel in development in the uk at this point (as far as I know) , where as 4 stroke diesels by Gardner, Perkins and various other manufacturers are relatively well understood so will be easier to develop, probably not as good as a 6-71 but at this point more plausible.
marathag
Banned
You don't see sleeve valves on 1500hp Dragsters,nor on Dodge 700HP Hellcat equipped vehicles. For reciprocating engines, gas or diesel, poppet valves were the best solution for efficiency and reliability.
For most ground applications, you don't see turbines at all, despite their power to weight advantages.
That's still a fairly weak argument. Just because something is being used does not make it the best thing for the task. If for example sleeve valves are superior, I highly doubt Dodge would go to the trouble of designing an entirely new engine using sleeve valves for a performance benefit, when instead they can use a more well known and cheaper alternative.
The thing is that during the time period being discussed sleeve valves did have real benefits. The problem was that as you get closer to the start of WW2 those benefits start to be eroded by technological leaps. The thing is you can't fault people for not foreseeing those leaps, you also cant fault those same people for continuing to develop and refine engines they were already working on rather than blowing it all up and starting pretty much from scratch.
marathag
Banned
Which ended when Bristol got Sodium cooled valves in the Pegasus, well before WWII. Across the Pond, Wright was doing it a bit sooner in the late '20s with the Whirlwind
marathag
Banned
They sort of did, with the Knight, Burt and other automotive sleeve valve engines of the 1920s were losing out in Gran Prix racing, and GM tested, and abandoned them quickly.
The biggest booster for Sleeve Valves would always be Harry Ricardo.
Yet this outdated, complex and apparently useless technology produced reliable, quiet and smooth running engines when it was used well, producing power that was usually only available from larger capacity engines.
The facts are that in the world of the high power piston engine neither Poppet valves or sleeve valves held sway over one another in the timeframe we are discussing, both were viable in AERO engines though sleeve valves are never going to be used in lower end auto engines as poppet valves are cheap and easy to fix and people don't like change.
The valve arrangement of top fuel dragsters has about as much bearing on this story as finding out what kind of cheese Harry Ricardo prefered on his Toast before the meeting with Sir John Carden.
marathag
Banned
Other than only two British companies were sticking with that tech, while France, Germany, Italy, Japan, Soviet and US companies went with poppet valves is kind of telling.
90% of the world's P.C's run on Microsoft does that make Apple PC's useless crap then?
Doesn’t look like either side are going to convince the other they are right. Shall we discuss it for another 13 pages, or just agree to differ?
marathag
Banned
Software is different from hardware. Macs have a gui that sits onto BSD Linux. PC can also run BSD, but without the same gui. You can also go the other way, OSX on PC.
Computer wise, it's more like why in the '70-80s you had the some computer companies using ECL logic vs TTL vs CMOS
marathag
Banned
such is the way of the Internet, and the days before the internet, as on USENET and BBS.
Arguments get so heated, as the stakes are so very low.....
allanpcameron
Donor
I am not by any means technically minded, so the distinction between poppet valves and sleeve values, I'm afraid, is a bit above my head. So that kind of debate isn't what's driving the narrative here. In 1933 a Ricardo designed 180hp diesel engine had been put into Vickers' designed A6E2, but at £400 per engine was deemed too expensive. The A6E3, with Horstmann suspension, was fitted with Thornycroft's RY12 marine diesel. The A6, from what I've read, was considered the very thing to replace the Mediums in service, but was too expensive for the Treasury. The twin machine gun turrets in front of the main turret on OTL A9 hark back to that Vickers sixteen tonner A6.
So, I'm now five years on. John Carden is still alive and knows that the old A6 fits the bill for the A12 in everything except armour thickness, and for that weight, heading for 20 tons, it is going to need a powerful engine. What is going into OTL Matilda II (A12) are two diesel bus engines which have Ricardo's old 180hp fingerprints all over them, because the specification is for diesel engines. Ricardo is the (British) man to see about diesel engines in the 1930s.
Yes, using the Napier Lion as is, like Nuffield is using the Liberty, clearly makes sense, and will continue to be a viable alternative if the Ricardo diesel turns out to be problematic. Remember the deal is only a handshake at this point. But the War Office specification for the A12 is looking for diesel power, so what is Vickers/Carden to do? Go to someone whose diesel engine (with sleeve valves) based on a Kestrel aero-engine has been used to set world records for diesel speed and endurance. Ask him to do on a cheaply bought, off the shelf, aero-engine, what he'd done on the much more expensive and unobtainable Kestrel. In the update I made that clear from Ricardo's perspective that keeping the Lion as it was would give Carden the power he wanted. What you hopefully end up with an affordable, and hopefully powerful and reliable, diesel engine. Is it more complex than just using the petrol original? Yes. Does it meet the A12 specification? Yes. Could you use the Culverin or Thornycroft, or design a new diesel from scratch? Yes.
OTL the original Valentine I had an AEC petrol engine, 130 hp, Valentine II & III had an AEC diesel providing 131 hp, with slightly better torque. The Valentine IV onwards was fitted with the GMC 6-71(S Stroke) Model 6004 providing 138hp and much improved torque. (Available after Lend-Lease became a thing?)
@marathag said that "Sleeve valves just wasn't worth the slight increase in power for the massive increase in complexity. For a diesel Lion, that should be in the 350-400hp range." A diesel Lion gives the ATL Valentine, or Cardenite as some are calling it, about three times the power of OTL. That gives me (I mean Carden) the expansion capability to up-armour and up-gun, at least till 1942/3.
I have to admit because pretty much all I've done on this forum is ASB that writing something without too much hindsight, handwavium is problematic. But I'm hoping that the decisions being made by Carden are consistent with the times and situation he was in. If not, I'll banish myself back to ASB.
Allan.
So, I'm now five years on. John Carden is still alive and knows that the old A6 fits the bill for the A12 in everything except armour thickness, and for that weight, heading for 20 tons, it is going to need a powerful engine. What is going into OTL Matilda II (A12) are two diesel bus engines which have Ricardo's old 180hp fingerprints all over them, because the specification is for diesel engines. Ricardo is the (British) man to see about diesel engines in the 1930s.
Yes, using the Napier Lion as is, like Nuffield is using the Liberty, clearly makes sense, and will continue to be a viable alternative if the Ricardo diesel turns out to be problematic. Remember the deal is only a handshake at this point. But the War Office specification for the A12 is looking for diesel power, so what is Vickers/Carden to do? Go to someone whose diesel engine (with sleeve valves) based on a Kestrel aero-engine has been used to set world records for diesel speed and endurance. Ask him to do on a cheaply bought, off the shelf, aero-engine, what he'd done on the much more expensive and unobtainable Kestrel. In the update I made that clear from Ricardo's perspective that keeping the Lion as it was would give Carden the power he wanted. What you hopefully end up with an affordable, and hopefully powerful and reliable, diesel engine. Is it more complex than just using the petrol original? Yes. Does it meet the A12 specification? Yes. Could you use the Culverin or Thornycroft, or design a new diesel from scratch? Yes.
OTL the original Valentine I had an AEC petrol engine, 130 hp, Valentine II & III had an AEC diesel providing 131 hp, with slightly better torque. The Valentine IV onwards was fitted with the GMC 6-71(S Stroke) Model 6004 providing 138hp and much improved torque. (Available after Lend-Lease became a thing?)
@marathag said that "Sleeve valves just wasn't worth the slight increase in power for the massive increase in complexity. For a diesel Lion, that should be in the 350-400hp range." A diesel Lion gives the ATL Valentine, or Cardenite as some are calling it, about three times the power of OTL. That gives me (I mean Carden) the expansion capability to up-armour and up-gun, at least till 1942/3.
I have to admit because pretty much all I've done on this forum is ASB that writing something without too much hindsight, handwavium is problematic. But I'm hoping that the decisions being made by Carden are consistent with the times and situation he was in. If not, I'll banish myself back to ASB.
Allan.
15 March 1938. 11:00hrs. London, England.
allanpcameron
Donor
15 March 1938. 11:00hrs. London, England.
The three men pored over the latest reports from Spain. As they did every week, all sources were scoured for any intelligence on the tactics and weapons being employed by both sides. As well as his reports for publication in newspapers, Colonel ‘Boney’ Fuller also passed on more complete accounts of what he was seeing. Part of the problem was that he was so enamoured with the Nationalist cause, that the team looking at them had to take some of what he was saying with a pinch of salt.
They were looking again at the various descriptions of what was happening with tanks. Fuller’s reports of the Panzer I being used by the Condor Legion were all very positive, but what was puzzling was why the Nationalists were trying to capture as many Soviet made T-26s as possible in running order. Reading between the lines, it seemed that the machine-gun armed German machine wasn’t able to deal with its Soviet counterpart. The T26 was based on the Vickers 6 tonner, and was armed with a 45mm cannon. This gun was more than capable of penetrating the Panzer, while the 7.92mm machine gun wasn’t able to deal with the T26. The Italian tanks, CV33 and CV35 suffered from the same problem. Fuller had remarked that efforts were being made to replace the MG13 on the Panzer I with a Breda 20mm autocannon, which would be able to penetrate the Soviet machine.
What British military intelligence made of this was that the Vickers Mark VI light tanks, which were similar to the Panzer I in armour and armament, would suffer from the same problems. An enemy armed with anything more that a rifle cartridge would be a serious threat to the light tanks. It was believed that the Panzer II was armed with a 20mm cannon, and the standard German anti-tank gun was fired a 37mm round. And since the light tanks were only armed with machine guns, though the Vickers .5-inch machine gun might be a bit better than the .303, they too would be unable to deal with any enemy machines. Vickers was working on a Mark VII light tank, designated A17, which had the standard 2-pdr gun in a turret. However, it was designed with the same 14mm armour thickness as the Mark VI. What was becoming clear from the Spanish Civil War was that tankettes and light tanks had very limited value.
The three men pored over the latest reports from Spain. As they did every week, all sources were scoured for any intelligence on the tactics and weapons being employed by both sides. As well as his reports for publication in newspapers, Colonel ‘Boney’ Fuller also passed on more complete accounts of what he was seeing. Part of the problem was that he was so enamoured with the Nationalist cause, that the team looking at them had to take some of what he was saying with a pinch of salt.
They were looking again at the various descriptions of what was happening with tanks. Fuller’s reports of the Panzer I being used by the Condor Legion were all very positive, but what was puzzling was why the Nationalists were trying to capture as many Soviet made T-26s as possible in running order. Reading between the lines, it seemed that the machine-gun armed German machine wasn’t able to deal with its Soviet counterpart. The T26 was based on the Vickers 6 tonner, and was armed with a 45mm cannon. This gun was more than capable of penetrating the Panzer, while the 7.92mm machine gun wasn’t able to deal with the T26. The Italian tanks, CV33 and CV35 suffered from the same problem. Fuller had remarked that efforts were being made to replace the MG13 on the Panzer I with a Breda 20mm autocannon, which would be able to penetrate the Soviet machine.
What British military intelligence made of this was that the Vickers Mark VI light tanks, which were similar to the Panzer I in armour and armament, would suffer from the same problems. An enemy armed with anything more that a rifle cartridge would be a serious threat to the light tanks. It was believed that the Panzer II was armed with a 20mm cannon, and the standard German anti-tank gun was fired a 37mm round. And since the light tanks were only armed with machine guns, though the Vickers .5-inch machine gun might be a bit better than the .303, they too would be unable to deal with any enemy machines. Vickers was working on a Mark VII light tank, designated A17, which had the standard 2-pdr gun in a turret. However, it was designed with the same 14mm armour thickness as the Mark VI. What was becoming clear from the Spanish Civil War was that tankettes and light tanks had very limited value.
- Status