{"version":"1.1.0","producer":"fm.getcarcurious","layer":"official","episode":{"title":"The Studebaker XH-9350: The Largest Piston Airplane Engine That Never Flew","url":"http://getcarcurious.com/episodes/the-studebaker-xh-9350-the-largest-piston-airplane-engine-that-never-flew","audioUrl":"https://mcdn.podbean.com/mf/web/sqe3hn7f7u5h9sbe/9350_final9o7ma.mp3","description":"The most monstrous WWII aircraft engine that you have never heard of is called the Studebaker XH-9350. A truly mind boggling project that Studebaker was the last option for when it began in 1942, it's an engine that would have been unmatched in aviation history had it been completed.\nDesigned as an H-layout, it was to displace 9,350ci and make north of 5,000hp on gasoline. The engine was almost 10ft long and was over 100\" wide as well. It was fed by two turbochargers that weighed 250lbs a piece and moved 14,500cfm of air.\nThis is the story of the engine's background, its development including some incredible single cylinder engines, and interesting gearhead tech, and finally a look at why the Army Air Corps believed that they needed it.\n \nFew have heard of this long lost project from the skunkworks of WWII.\n"},"annotations":[{"id":457380,"startTime":72.9,"endTime":89.1,"type":"part","title":"Studebaker XH-9350","url":"/glossary/studebaker-xh-9350","quote":"This is the story of what would have been the absolute and final boss of US piston aircraft engines, the Studebaker XH9350. A mill planned to make 5,000 horsepower, displays 9,350 cubic inches in an H-style layout...","canonicalId":"part:studebaker-xh-9350","priority":1.0,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"The Studebaker XH-9350 was a massive, experimental 24-cylinder liquid-cooled aircraft engine developed during World War II. Designed in an 'H' configuration, it was projected to produce 5,000 to 6,000 horsepower from an enormous 9,350 cubic inches of displacement. The project was canceled at the end of the war before a complete engine could fly, as turbine jet engines rendered large piston engines obsolete.","simplifiedExplanation":"This was a giant experimental engine built by the Studebaker car company during World War II for military planes. It was incredibly powerful and heavy, but the war ended and jet engines became the future, so it was never actually used in a plane.","sourceStartTime":72.9,"sourceEndTime":89.1}},{"id":457381,"startTime":148.5,"endTime":153.5,"type":"brand","title":"Rolls-Royce","url":"/glossary/rolls-royce","quote":"...when military planners in the US came to a stark realization after getting hold of a British Rolls-Royce Kestrel engine. They were hopelessly behind.","canonicalId":"brand:rolls-royce","priority":0.5,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"Rolls-Royce is a legendary British luxury car manufacturer and aero-engine manufacturer founded in 1904. During World War II, their aviation division designed and produced some of the most successful piston aircraft engines in history, most notably the Merlin V12 which powered the P-51 Mustang and Supermarine Spitfire.","simplifiedExplanation":"A famous British company known today for making ultra-luxurious cars, but historically famous for building incredibly powerful and reliable airplane engines during World War II.","sourceStartTime":148.5,"sourceEndTime":153.5}},{"id":457382,"startTime":276.9,"endTime":293.4,"type":"person","title":"S.D. Herron","url":"/glossary/s-d-herron","quote":"Sam, or more commonly known as S.D. Herron, was one of the leading engineers at Wright Field who was working in the power plant branch. Herron came to the States from his native England a few years before and would really make his mark in the development of high-octane fuels...","canonicalId":"person:s-d-herron","priority":0.8,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"Sam D. Herron was an influential British-born aeronautical engineer who worked for the US military at Wright Field. He is widely credited with pioneering the development of sodium-cooled exhaust valves and high-octane aviation fuels, which dramatically increased the power limits and reliability of piston aircraft engines.","simplifiedExplanation":"A brilliant engineer who invented a way to cool down hot engine valves using liquid sodium, which stopped high-performance engines from melting or exploding under heavy loads.","sourceStartTime":276.9,"sourceEndTime":293.4}},{"id":457383,"startTime":278.9,"endTime":284.0,"type":"place","title":"Wright Field","url":"/glossary/wright-field","quote":"Sam, or more commonly known as S.D. Herron, was one of the leading engineers at Wright Field who was working in the power plant branch.","canonicalId":"place:wright-field","priority":0.6,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"Wright Field was a military airfield near Dayton, Ohio, that served as the primary research, development, and testing hub for the US Army Air Corps (and later Army Air Forces) during the golden age of aviation and World War II. It is now part of Wright-Patterson Air Force Base.","simplifiedExplanation":"A famous military base in Ohio where the US military tested and developed advanced airplanes and engines during World War II.","sourceStartTime":278.9,"sourceEndTime":284.0}},{"id":457384,"startTime":313.1,"endTime":329.4,"type":"person","title":"Harry Ricardo","url":"/glossary/harry-ricardo","quote":"Sir Harry Ricardo's impact on the development of the internal combustion engine is immeasurable. In many ways, he's one of the most recognized authorities on the basic theories engines still run on today.","canonicalId":"person:harry-ricardo","priority":0.7,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"Sir Harry Ricardo was a prominent British engineer and researcher whose work laid the foundational theories for modern internal combustion engines. He made massive contributions to the understanding of engine knock, combustion chamber design, and heavily championed sleeve-valve technology for high-output engines.","simplifiedExplanation":"One of the most famous engine scientists in history, who figured out many of the basic rules for how modern car and plane engines burn fuel and make power.","sourceStartTime":313.1,"sourceEndTime":329.4}},{"id":457385,"startTime":347.0,"endTime":352.8,"type":"part","title":"sleeve valve","url":"/glossary/sleeve-valve","quote":"In 1927 he published an influential paper that championed the idea of sleeve valve engines over poppet valve-style engines, the types of which all of us watching this video are used to seeing.","canonicalId":"part:sleeve-valve","priority":0.8,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"A sleeve valve is a type of valve mechanism for piston engines that uses one or more sliding cylindrical sleeves located between the piston and the cylinder wall. As the sleeve rotates or slides, ports in its side align with intake and exhaust ports in the cylinder block, eliminating the need for traditional overhead poppet valves.","simplifiedExplanation":"Instead of using little metal mushrooms (valves) that push open and closed at the top of the engine, this design uses a sliding metal tube inside the cylinder to let air in and out.","sourceStartTime":347.0,"sourceEndTime":352.8}},{"id":457386,"startTime":366.6,"endTime":375.3,"type":"term","title":"specific output","url":"/glossary/specific-output","quote":"It was Ricardo's contention that piston engines had reached their limit of specific output, meaning the maximum power per cubic inch displacement they could produce...","canonicalId":"term:specific-output","priority":0.6,"confidence":0.95,"source":"gemini-3.5-flash","data":{"explanation":"Specific output is a metric used to evaluate an engine's efficiency and performance relative to its size, typically calculated as horsepower per liter or horsepower per cubic inch of engine displacement. High specific output indicates highly optimized combustion, airflow, and mechanical design.","simplifiedExplanation":"A way to measure how much power an engine makes compared to how big it is. A small engine that makes a lot of power has high specific output.","sourceStartTime":366.6,"sourceEndTime":375.3}},{"id":457387,"startTime":615.8,"endTime":626.2,"type":"part","title":"sodium-filled exhaust valves","url":"/glossary/sodium-filled-exhaust-valves","quote":"He worked on various cylinder head designs, various boost options, used experimental fuels and added one last detail that put the whole works over the top. Sodium filled exhaust valves.","canonicalId":"part:sodium-filled-exhaust-valves","priority":0.8,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"Sodium-filled valves feature a hollow stem containing metallic sodium, which melts at operating temperatures. As the valve moves, the liquid sodium sloshes back and forth, transferring heat away from the extremely hot valve face and up into the cooler valve guide and cylinder head, preventing pre-ignition and valve failure.","simplifiedExplanation":"Engine valves that have liquid metal inside them. As the engine runs, the liquid metal sloshes around and carries heat away from the hottest parts, keeping the engine from overheating and breaking.","sourceStartTime":615.8,"sourceEndTime":626.2}},{"id":457388,"startTime":643.0,"endTime":653.8,"type":"concept","title":"hyper engine","url":"/glossary/hyper-engine","quote":"With this concept, the concept of the hyper engine was born. Heron's achievement of one horsepower per cubic inch was beyond crazy for the time.","canonicalId":"concept:hyper-engine","priority":0.7,"confidence":0.95,"source":"gemini-3.5-flash","data":{"explanation":"The 'hyper engine' was a US military design philosophy and development project in the 1930s aimed at producing liquid-cooled aircraft engines capable of generating at least one horsepower per cubic inch of displacement. This milestone required major breakthroughs in fuels, cooling, and metallurgy.","simplifiedExplanation":"A special military project to build super-high-performance engines that could make a massive amount of power for their size.","sourceStartTime":643.0,"sourceEndTime":653.8}},{"id":457389,"startTime":910.3,"endTime":922.2,"type":"term","title":"specific fuel consumption","url":"/glossary/specific-fuel-consumption","quote":"In their responses they had to provide details on the engines specific fuel consumption at 40, 50, 60 and 70% power levels...","canonicalId":"term:specific-fuel-consumption","priority":0.7,"confidence":0.95,"source":"gemini-3.5-flash","data":{"explanation":"Brake Specific Fuel Consumption (BSFC) is a measure of the fuel efficiency of an internal combustion engine. It calculates the rate of fuel consumption divided by the power produced, allowing engineers to compare the efficiency of different engines regardless of their overall size.","simplifiedExplanation":"A measurement of how much fuel an engine burns to make a certain amount of power. Lower numbers mean the engine is more efficient.","sourceStartTime":910.3,"sourceEndTime":922.2}},{"id":457390,"startTime":1063.9,"endTime":1080.2,"type":"person","title":"Norman Neville Tilly","url":"/glossary/norman-neville-tilly","quote":"That help was the addition of a brilliant engineer named Norman Neville Tilly. Tilly had worked with Heron on the hyper cylinders back in the day, designed engines for continental and lycoming...","canonicalId":"person:norman-neville-tilly","priority":0.7,"confidence":1.0,"source":"gemini-3.5-flash","data":{"explanation":"Norman Neville Tilly was a highly respected American aeronautical engineer who worked on early hyper engine development, designed engines for Continental and Lycoming, and served as the chief engineer for Studebaker's aviation division during their World War II military projects.","simplifiedExplanation":"A top-tier engine designer hired by Studebaker to lead the development of their massive experimental aircraft engine.","sourceStartTime":1063.9,"sourceEndTime":1080.2}},{"id":457391,"startTime":1565.68,"endTime":1571.2,"type":"car","title":"Subaru Uncharted","url":"/cars/subaru/uncharted","image":"https://s3.amazonaws.com/subarumedia.iconicweb.com/mediasite/libraryImages/2026_Subaru_Uncharted_01__mid.jpg","quote":"...urn out of a cylinder that had an 8 inch bore was uncharted territory at this time in aviation engine history...","canonicalId":"car:subaru:uncharted","priority":0.5,"source":"hybrid-fuzzy+gemini-3.5-flash","data":{"explanation":"There is no actual vehicle called the 'Subaru Uncharted.' This phrase refers to the aviation heritage of Subaru's parent company, Fuji Heavy Industries (formerly Nakajima Aircraft Company), and their historical engineering efforts in developing large-bore aircraft engines, which was considered uncharted territory at the time.","simplifiedExplanation":"The 'Subaru Uncharted' is not a real car. It is a misunderstanding of a phrase describing how the company that eventually became Subaru used to make giant airplane engines, which was brand new technology for them at the time.","imageAttribution":"Subaru U.S. Media Center","imageSourceUrl":"https://media.subaru.com/image-gallery.do?method=view&imageGalleryId=605&mid=397","sourceStartTime":1565.68,"sourceEndTime":1571.2}},{"id":457392,"startTime":1713.9,"endTime":1724.4,"type":"part","title":"Chevrolet Big Block","url":"/glossary/chevrolet-big-block","quote":"The power production out of the single cylinder 8 inch by 8 inch 6.8 to 1 compression engine was 338 horsepower out of a displacement of 402.12 cubic inches so it was basically a one whole big block Chevy.","canonicalId":"part:chevrolet-big-block","priority":0.4,"confidence":0.9,"source":"gemini-3.5-flash","data":{"explanation":"The Chevrolet Big Block is a family of large-displacement V8 engines produced by General Motors starting in 1958. Renowned for their heavy-duty construction and massive torque, they became legendary in muscle cars, heavy trucks, and marine racing applications.","simplifiedExplanation":"A famous, very large and powerful V8 engine made by Chevrolet that is popular in classic muscle cars and heavy-duty trucks.","sourceStartTime":1713.9,"sourceEndTime":1724.4}},{"id":457393,"startTime":2056.0,"endTime":2063.8,"type":"place","title":"South Bend","url":"/glossary/south-bend","quote":"Interestingly, Studebaker was well into the construction of a facility to actually build and test a complete engine and South Bend.","canonicalId":"place:south-bend","priority":0.6,"confidence":0.85,"source":"gemini-3.5-flash","data":{"explanation":"South Bend, Indiana, was the historic headquarters and primary manufacturing hub of the Studebaker Corporation for over a century. The massive industrial complex in South Bend produced horse-drawn carriages, military equipment, and millions of automobiles before production ceased in December 1963.","simplifiedExplanation":"The city in Indiana where the Studebaker car company was based and where they built their cars and engines.","sourceStartTime":2056.0,"sourceEndTime":2063.8}},{"id":457394,"startTime":2435.4,"endTime":2445.4,"type":"person","title":"Brian Lohnes","url":"/glossary/brian-lohnes","quote":"I'm Brian Lohnes, thanks for watching and as always, knowledge is horsepower.","canonicalId":"person:brian-lohnes","priority":0.5,"confidence":0.95,"source":"gemini-3.5-flash","data":{"explanation":"Brian Lohnes is an automotive journalist, drag racing announcer, and host of the Dork-O-Motive podcast. He is well-known in the automotive community for his encyclopedic knowledge of mechanical history, vintage heavy machinery, drag racing, and hot rods.","simplifiedExplanation":"The host of this podcast, who is an expert on the history of engines, cars, and mechanical inventions.","sourceStartTime":2435.4,"sourceEndTime":2445.4}}],"speakers":[{"id":"s1","name":"Brian Lohnes","role":"host"}],"transcripts":[{"url":"http://getcarcurious.com/episodes/the-studebaker-xh-9350-the-largest-piston-airplane-engine-that-never-flew/transcript.vtt","type":"text/vtt"}],"alignmentMode":"scalar","fallbackOffset":0.0}