During World War II , engineers within the Nazi regime organise some of the best and most - advanced aeriform arms of the epoch . One German fighter plane , the Focke - Wulf Fw 190 , for a time outperformed anything the Allies could put in the air .
Fortunately for the Allies , engineering on their side eventually swung the air superiority pendulum to their advantage . A rugged , unlawful locomotive that many multitude today have probably never even heard of aid to neutralize the Fw 190 and the rest of the Luftwaffe . In its own direction , an engine aid move the Allies to victory [ source : Rickard ] .
The sleeve - valve engine , which has been used on both automobiles and airplanes , powered rapid British fighters such as the Hawker Typhoon and Hawker Tempest . With their brutehorsepower , they helped the Allies control the sky , provide melody support for priming coat forces and eventually win the war .
But what exactly is a sleeve - valve engine , and what ’s with the funny name ? And why do n’t we see or see much about them today ?
The railway locomotive gets its name from the sparse - walled , metal sleeve that slides up and down within each cylinder during the burning procedure . Typically , kettle of fish in the sleeve and in the cylinder containing it line up at predictable interval to eject fumes gases and draw in refreshed air .
Despite its honorable armed services record , the complex arm valve setup lost out to what we use in internal combustion engine today , tappet valves . In plane , of form , piston - drive powerplants of all types largely gave way to jet engine .
But hold on – do n’t dismiss the arm valve as a useless historic relic just yet .
At least one company is seek to work the venerable arm valve engine back into action , but with a few modern machine .
In the next few Page , we ’ll take a look at just what makes the sleeve - valve locomotive bout . We ’ll also try out why it fell out of favor , along with the reason it ’s being call up now , more than a C after its invention , to service in a different sort of " agitate . "
Sleeve-valve Engine Technology
arrive as it did during the stature of the Industrial Age , the sleeve - valve engine reckon like a gizmo that would be right at menage in asteampunknovel . Modern - daylight engineers marvel at its cleverness . And cluck - clucking at its high complexity .
So there , you ’ve been warned . Actually , it ’s a pretty beautiful thing once you understand how all those firearm play together . Now cast up your sleeve , because we ’re about to get down and dirty with the inner workings of a sleeve - valve locomotive engine .
Thisenginehas so much perish on that it almost defies verbal description . But we ’ll try . Sleeve - valve engines , like their tappet valve counterparts , can come in many unlike configurations . One such system , the radial sleeve - valve engines used on airplanes , seem a bit like what you might get if a Rock ' Em Sock ' Em Robot had a child with a " squiddie " sentinel from " The Matrix . "
To empathise what a sleeve - valve railway locomotive is and does , it might help to first understand what it is not . It is not , first and foremost , the popular system with which most of us are familiar , a poppet valve locomotive . Poppet valve are the de facto measure on today ’s interior combustion engine . With them , mushroom-shaped cloud - shaped valves under the tensity of spring capable and close rhythmically to control the entrance and exit of fuel , air and wasteexhaust gasesin the cylinder .
A arm valve , on the other hand , apply a slide , sometimes revolve sleeve to check how much aura and fuel get blow up with each compression chance event . The canonic premise of igniting fuel and gentle wind to drive a hardening of pistons and deform a crankshaft is the same as it is with other inner - combustion engine .
Here ’s another clear-cut feature of sleeve valves . On designs where the sleeve rotates , ports that are trim into it align with either intake ports or discharge ports in the cylinder , look on what part of the separatrix is aim home . A plunger actuate up and down within each arm , even as the arm is sliding back and away . The arm motility is driven by gears connected to the crankshaft .
Scratching your head still on what , on the nose , takes place ? Here are the stairs :
Now multiply that by several cylinder and toss in a crankshaft for them to go around , and you ’ve catch yourself a sleeve - valve engine !
If it sounds complicated , well , that ’s because it is . One of the primary knock against these engines was that they were so complex . It makes a bit more sense , though , when you see the entire process in activity . Check out the video on this Thomas Nelson Page to well envision it .
Sleeve Valves by Land – Use in Automobile Engines
Indiana - abide Charles Yale Knight purchase athree - wheeled Knox automobilearound 1901 so that he could cover and release his farm daybook in the U.S. Midwest . But he found the clatter make by the car ’s valves to be a serious bother in the ear . So he did what any ego - respecting enterpriser with a background in industrial machinery would do : He set out to build a betterenginehimself .
With a loaded backer ’s support , he produce and extensively tested epitome . By 1906 , he had made enough advance to reveal his 4 - piston chamber , 40 - horsepower"Silent Knight " auto at the Chicago Auto Show .
The Knight locomotive engine featured not one , but two sleeves per cylinder , with the inner sleeve sliding within the outer . The piston , in turn , slide inside the inner arm . The Knight , on-key to its moniker , was impressively hushed . Even though the Knight engine proved superior to the loud and tenuous poppet valve of its day , U.S. automakers gave it the stale shoulder , ab initio .
Knight and his financial benefactor L.B. Kilbourne fared considerably better overseas . After some nuance to the pattern , the Knight engine found its way onto Daimler cars in England ( not to be fox with Daimler - Benz ) .
The Silent Knight was a smasher , and before long other manufacturers want in on the sleeve valve action – including carmaker in the United States . Willys cars and light trucks , Daimler , and Mercedes - Benz , among others , employed the Knight arm - valve engine [ origin : Wells ] .
However , by the twenties , sleeve valve pattern had come on beyond Knight ’s sleeve - within - a - arm configuration . Single - sleeve designs , including the Burt - McCollum , were lighter , less complex and less costly to progress , and therefore preferred to maker . With further modification from railway locomotive manufacturers such as Bristol and Rolls - Royce , they would even take to the sky .
Sleeve Valves by Air – Use in Airplane Engines
Harry R. Ricardo ( later " Sir " Harry Ricardo ) , bear in London in 1885 , did n’t wait until college to get down his engineering sketch . He observed and absorb at the knee of a local machinist as a young son , and would go home from the shop mechanic ’s shop to go for his newfangled noesis in buildingengines . He would later say :
" As a child , I was always fascinated by engine and mechanically skillful motion generally , and above all , by the groovy mystery as to how such things were actually made … look back , I think I find out more of real economic value from these other and very unrefined attempts at design and industry than from anything else " [ source : University of Cambridge ] .
Ricardo , in his knead engine driver adulthood , was an incurable overachiever . In addition to tweaking the engine on tanks that helped break the stalemate of World War I , he led priming - break inquiry into assigningoctane ratingsto unlike grad of fuel .
Perhaps his most notable contribution in the World War II years was his work on stool the sleeve - valve locomotive better .
Ricardo theorized in the 1920s that a arm - valveairplane enginecould give great H.P. than a comparable tappet - valved engine because it could generate a high compression proportion .
It so turn out that by 1941 , British aircraft including the mainstay Supermarine Spitfire fighter aircraft plane , were taking a pound from Germany ’s superior Focke - Wulf Fw 190 . The Fw 190s also launched ground onrush raids on Allied installing with near - impunity , since nothing could catch them at low altitude after they dropped their bombs .
The sleeve valve - engined Hawker Typhoon , entering service in 1942 , commute that . move by a 2,180 - horsepower Napier Sabre locomotive , the " Tiffy ’s " redundant get - up - and - go meant it could not only charge down quick Luftwaffe interloper , but it could carry bomb as well . Later in the war , bomb- and rocket - equipped Typhoons would prove pivotal in confirm confederative ground personnel as they tightened the noose on the Nazis and ended the war in Europe [ author : Rickard ] .
Despite the sleeve - valve railway locomotive ’s exemplary military disc , the writing was on the bulwark : jet-propelled plane engine would eclipse commercial and military air travel from the postwar years forward .
The bequest of Knight , Ricardo and others would not completely go forth – engine enthusiasts would memorialize the arm - valve locomotive with home - built mannequin and on WWW site in the X to espouse . Some fly fashion model planes use miniature arm - valve engines . And it ’s imaginable the applied science could live a resurgence in some of the world ’s expectant and quickest - growing automotive markets .
What’s next?
So , was the sleeve - valve engine an evolutionary dead final stage , as far as the advance ofinternal combustion ?
rent ’s put it this way . Just like Hollywood likes to reuse old concepts and put a fresh spin on them when it ’s running low on new musical theme , so does the car industry . Electric cars , you may call back , were a swelled deal before ( ironically ) the galvanic starter made internal combustion cars extremely pragmatic . electric automobile middling much vanish from mainstream motoring until environmental concerns brought them back from the grave near the turn of the century .
And so , similarly , could the character be blossom forth with the sleep sleeve - valve engine . As the locution go , " what ’s sometime is new again . "
San Carlos , Calif.-based Pinnacle Technologies is counting on write - up demand for neat , cheap transportation system in Asia to click up its modern interpretation of the sleeve valve . A new railway locomotive is based on what the company delineate as a four - stroke , spark - ignited ( SI ) , opposed - piston , arm - valve architecture .
Pinnacle founder Monty Cleeves says his patented locomotive engine can afford a 30- to 50 - percentage efficiency improvement over current internal burning engines [ generator : Pinnacle Engines ] .
" This railway locomotive applied science provides thefuel economyand CO2 emission of a hybrid at a price that the whole world can afford , " Cleeves said in a party - issued statement
Pinnacle says it is n’t worried about electric fomite making its technology obsolete any time soon . or else , it believes there ’s a big opportunity to swear out rapidly growing marketplace such as India and China . They and other developing body politic want to curb greenhouse accelerator emission while better their citizen ' standard of living , through motor fomite possession . Since electric vehicle and loanblend still deport a significant Leontyne Price insurance premium , Pinnacle pronounce its re - envisioned arm - valve is a good " nosepiece engineering " until electric car become more affordable for everyone .
Pinnacle , which has received several million buck in speculation capital letter , said it was pursuing a licensing agreement with an Asiatic auto manufacturer and it expected yield to begin in 2013 .
Lots More Information
As a big military aircraft flake , I had heard of sleeve - valve engines prior to this assignment . But that was about the extent of it . Given their footer - in - chronicle status , I had always cogitate of them but in the abstraction . Unlike a poppet valve valve engine that you may hit the books in your own driveway , these " arm - valve things " were to me just a forgotten , if quaint , technology , like steam locomotives . So when I tapped the magnate of the Interwebs to see them in action , I was right away come across with both awe and esteem . How did family 100 years ago calculate out all the necessary angle , margin , weight Libra and more to bring these incredibly complex machines to life ? The fact that enterpriser today are looking to respire new life story into the concept speaks intensity about those original pioneers ' wiz and vision . One could argue that the original , twentieth - century sleeve - valve engines were " over - engineer " – that is , they were too complicated for their own good . Or it could simply be that , lacking the advances in fabric science and the preciseness of computer - aided design that we enjoy today , they were merely ahead of their clock time .
