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V16 engine

A V16 engine is a type of featuring sixteen cylinders arranged in two banks of eight, forming a V configuration that shares a common , typically with a V-angle between 45 and 135 degrees to optimize balance and compactness. This design combines the smoothness of a multi-cylinder layout with high , allowing for large displacements and substantial output, though it demands precise engineering for and cooling. The V16 configuration first gained prominence in the early amid the push for greater power in automobiles and , with initial developments tied to efforts. In automotive applications, the 1930 marked the debut of the first production car with a V16, featuring a 7.4-liter (452 ) overhead-valve engine rated at 165–185 horsepower, designed for ultra- vehicles to rival European marques like Rolls-Royce. Produced until 1937 with around 4,000 units built, it emphasized refined performance over speed, achieving top speeds near 100 mph while incorporating innovations like hydraulic valve silencers for whisper-quiet operation. Concurrently, the Marmon Sixteen (1931–1933) offered a similar 8.0-liter V16 with 200 horsepower in a coachbuilt , though fewer than 400 were made due to the . In racing, V16s powered dominant machines like the 1930s Type A–C cars, with supercharged 6.0-liter engines producing 295–520 horsepower for record-breaking speeds over 200 mph. Postwar, examples include the 1951 BRM P15 engine, a supercharged 1.5-liter V16 delivering around 600 horsepower, though reliability issues limited its success. Modern concepts, such as the 2003 , revived the layout with a 13.6-liter all-aluminum V16 generating 1,000 horsepower and 1,000 lb-ft of torque, showcasing potential for hybrid applications but remaining a showpiece. Beyond automobiles, V16 engines found niche roles in aviation, marine, and rail sectors where extreme power outweighed complexity. In aircraft, Duesenberg's 1917 Model H—a 55.6-liter (3,393 ) 45-degree V16 prototype producing up to 900 horsepower—was developed during but shelved after the war due to its 7-foot length and aircraft size mismatches. The 1940s Chrysler XIV-2220 inverted V16, at 36.4 liters and 2,500 horsepower, was prototyped as a radial alternative for fighters like the P-47 but never entered . For marine use, V16 engines, including diesels that emerged in the – for large vessels requiring reliable high , evolved into contemporary gasoline offerings like Sixteen Power's 2017 14.0-liter V16, which delivers 900–2,000 horsepower with advanced cooling and for high-duty boats. In locomotives, the (1969–1971) employed twin 16-645 V16 diesels for a combined 6,600 horsepower, hauling heavy freight on Union Pacific lines until retirement in the 1980s, representing the pinnacle of V16 rail power. Despite their impressive capabilities, V16s remain rare today due to high manufacturing costs, packaging challenges, fuel inefficiency, and stricter emissions standards favoring smaller, turbocharged alternatives.

Design and principles

Configuration and operation

A V16 engine is a V-type internal combustion engine consisting of two banks of eight cylinders each, arranged symmetrically around a common crankshaft to form a V configuration. This layout allows for a compact design relative to an inline-16 engine while providing high power output potential. The V-angle between the cylinder banks typically is 45° or 135°, with these angles enabling even firing intervals of 45° per crankshaft revolution, minimizing vibrations and ensuring smooth operation. The in a V16 engine is sequenced to distribute events evenly across the rotation, often following a such as 1-12-8-11-7-14-5-16-4-15-3-10-6-9-2-13 for balanced delivery in 45° or 135° V configurations. This order alternates between banks to achieve uniform torque pulses every 45° of crank angle in a four-stroke cycle. The features eight throws (crankpins), each connecting to connecting rods from paired cylinders, enabling the of the pistons while withstanding high torsional loads. In operation, most V16 engines follow a four-stroke cycle, where each undergoes , , , and exhaust phases over two revolutions. Camshaft arrangements vary by design: early automotive examples often used overhead (OHV) systems with a single in the block actuating via pushrods and rockers, while advanced configurations employ single overhead (SOHC) or dual overhead (DOHC) setups per bank for precise control and higher revving capability. is optimized for , with typically opening 10–20° before top dead center (TDC) on the intake and closing 40–60° after dead center (BDC), while exhaust open 40–70° before BDC on the and close 5–15° after TDC; exact durations depend on . Two-stroke V16 variants, primarily in applications, complete the cycle in one revolution using piston-ported and exhaust, eliminating the need for and enabling higher density at lower speeds. The total displacement D of a V16 engine is determined by the formula D = 16 \times \frac{\pi}{4} b^2 s, where b is the cylinder bore diameter and s is the piston length, both measured in consistent units (e.g., meters for liters output). For instance, the Cadillac V16 engine achieved a displacement of 7.4 L through its specific bore and dimensions. V16 engines primarily operate on in automotive contexts, utilizing spark ignition systems where an from plugs ignites the air-fuel mixture near TDC of the stroke. Diesel V16 engines, common in , marine, and heavy machinery applications, rely on ignition, where high compression ratios (typically 14:1 to 20:1) heat the air sufficiently to auto-ignite injected fuel without sparks.

Balance and performance characteristics

The inherent balance of a V16 engine arises from the cancellation of primary and secondary reciprocating forces, enabled by a narrow V-angle such as 45° or 135° and the even distribution across 16 cylinders. The two banks of eight cylinders each act like paired inline-eight configurations, where the symmetric motions and design neutralize vertical and horizontal forces without the need for additional balancing shafts, leading to exceptionally low levels. This results in smoother operation than an inline-16 , which would require a prohibitively long prone to torsional flex and unbalanced moments. A key performance attribute is the firing interval of 45° crankshaft rotation between consecutive power strokes in a typical 4-stroke V16, achieved through an even that minimizes pulsations and delivers seamless power output. This close spacing contributes to the engine's ultra-smooth idle and , with reduced stress on components compared to engines with wider firing intervals. In terms of output, supercharged V16 variants in historical applications have demonstrated power densities up to 400 per liter, while more conservative road-oriented examples range around 80-120 per liter in naturally aspirated form. characteristics feature broad, flat curves spanning several thousand RPM, enabling consistent high-end performance; for instance, the Type C V16 produced 520 and 630 lb-ft from 6 liters. Historical gasoline V16 engines, such as the Series 452, achieved power-to-weight ratios around 0.3 / due to their robust construction, though optimized designs approached 1.5 / or higher. Thermal management in V16 engines is critical given the heat generated by their large cylinder banks and high combustion volumes. Liquid cooling systems predominate to efficiently dissipate through coolant circulation, maintaining optimal operating temperatures and supporting higher thermal efficiencies of 25-35% in variants; , while simpler, is less common due to insufficient dissipation capacity for such scales and has been largely limited to experimental uses. The brake mean effective pressure (BMEP), a measure of an engine's volumetric efficiency and torque production, scales favorably in V16 designs due to their multi-cylinder layout and smooth dynamics. It is calculated as: \text{BMEP} = \frac{\text{Power} \times 2 \times \text{number of revolutions per power stroke}}{\text{displacement} \times \text{engine speed}} For a 4-stroke V16, the number of revolutions per power stroke is 2, allowing BMEP values often exceeding 10-15 bar in tuned applications, which underscores the configuration's ability to extract high work from large displacements without excessive stress.

History

Early development (pre-1930)

The pursuit of higher power outputs in early 20th-century engines, particularly for during , spurred interest in configurations exceeding the V12, as designers sought to balance increased displacement with compactness and reliability. The war's demands for potent powerplants influenced multi-cylinder innovations, transitioning concepts from military applications to potential automotive use. Pioneering efforts included the 1915 U-16 aircraft engine, a 24.3-liter 16-cylinder design with two parallel inline-8 banks sharing a common crankcase and dual crankshafts, developed for French military bombers but limited by production delays and the war's end. In the U.S., the brothers advanced true V16 technology with the Model H in 1918, a 55.6-liter, 45-degree V16 contracted by the U.S. Army for high-performance aircraft; it featured three valves per cylinder (one intake, two exhaust), a walking beam , dual ignition, and four carburetors, achieving up to 900 horsepower in tests despite its 1,575-pound geared weight. Prototypes ran starting in June 1918, with the first completed that year and a second in January 1919, though only a few were built before cancellations. Howard Marmon began automotive-focused V16 experiments in 1927 at , targeting a 490-cubic-inch overhead-valve aluminum-block design for luxury vehicles, with initial testing that year influencing subsequent American efforts. Jesse , Packard's chief engineer, contributed through 1910s-1920s V12 work like the Twin-Six and aircraft engine, fostering multi-cylinder expertise that conceptually extended to V16 possibilities, while European firms like prioritized V8 and V12 aviation engines without notable pre-1930 V16 prototypes. These early prototypes encountered formidable engineering hurdles, notably in fabrication—requiring robust of extended shafts with eight crank throws to handle high torsional loads without whipping or failure—and systems, where maintaining oil pressure and flow to the remote outer cylinders in long banks proved complex amid heat and vibration. The Model H exemplified these issues, its 7.5-foot length complicating aircraft integration and testing revealing inconsistencies in power delivery and oil distribution. As the 1920s drew to a close, surging demand in the automotive sector for ultra-refined, high-displacement engines to signify prestige amid economic prosperity accelerated V16 maturation, paving the way for production models by even as the loomed.

Production and wartime use (1930s-1940s)

The Cadillac V-16 engine marked the launch of the first mass-produced V16 for automotive use in , debuting in the Series 452/90 cars with a 7.4-liter (452 ) overhead-valve design producing 165 horsepower, featuring cylinder blocks, an aluminum , and innovative hydraulic lifters for silent operation. This configuration, with a 45-degree bank angle, emphasized smoothness and power for high-end vehicles amid the emerging market. Other American luxury manufacturers followed with V16 offerings, including the Marmon Sixteen introduced in , which featured an 8.0-liter (491 cubic inch) all-aluminum overhead-valve engine delivering 200 horsepower at 3,400 rpm and a 45-degree bank angle for exceptional performance-to-weight ratio. Pierce-Arrow explored V16 concepts in the early as part of the multi-cylinder competition but did not advance to significant production, opting instead for V12 engines in their Silver Arrow models. Overall production volumes for these V16s remained low due to the Great Depression's economic constraints; Cadillac built approximately 2,887 units in 1930 alone but saw totals drop sharply to around 4,000 across the decade, while Marmon produced only about 390 Sixteens from to 1933. During the , wartime demands led to experimental V16 adaptations, such as Chrysler's XI-2220 inverted 60-degree V16 prototype, a 2,220-cubic-inch liquid-cooled hemi design derived from paired V8 concepts that achieved 2,500 horsepower through supercharging, intended for but ultimately shelved after limited testing in 1945. Cadillac's V16 production concluded in December 1940, just before World War II's material shortages and rationing of metals like steel and aluminum halted all civilian automotive manufacturing in February 1942, effectively ending the pre-war era of V16 engines in cars.

Post-war and modern era (1950s-present)

Following , the V16 engine configuration saw a marked shift away from luxury automotive applications toward industrial and heavy-duty uses, particularly in form for and power generation. This transition was driven by the need for high-power, reliable engines in sectors like , where the V16's capacity for substantial torque and durability proved advantageous. A seminal example is the Electro-Motive Division (EMD) 16-567 series, a two-stroke V16 introduced in its turbocharged variant in 1958 for the SD24 . This engine delivered 2,400 horsepower, enabling efficient freight hauling and contributing to the widespread adoption of diesel-electrics in North American railroading during the late and . In the and , V16 engines experienced sporadic revivals in high-performance automotive contexts, though production remained limited. The most notable was the , unveiled in 1989 and entering limited production in 1991, featuring a transversely mounted 6.0-liter DOHC V16 gasoline engine producing 540 horsepower. Developed by former engineers, this engine combined two V8 blocks for a unique and smooth operation, powering a mid-engine with just 12 units ultimately built before the project folded in 2003 due to financial challenges. From the onward, V16 engines have largely persisted in industrial applications, such as stationary generators, where their high output supports demanding power needs without the packaging constraints of passenger vehicles. The 3516, a V16 four-stroke , exemplifies this, offering over 2,000 horsepower in generator sets for mission-critical and , with ratings up to 1,750 ekW at 60 Hz. These engines emphasize reliability and in sectors like data centers and oil fields, far outlasting automotive uses. Contemporary trends in V16 development focus on hybrid integration to address emissions compliance and efficiency demands, amid stricter global regulations like Euro 7 and EPA Tier 4 standards. The , revealed in 2024, marks a rare automotive resurgence with an 8.6-liter naturally aspirated V16 gasoline engine paired with three electric motors in a setup, yielding 1,800 total horsepower while aiming for reduced CO2 output through . However, the configuration's size and complexity pose ongoing challenges, often leading to downsizing in favor of smaller cylinder counts or full electrification in mainstream applications. In the , V16 engines occupy a niche role, primarily in custom hypercars, , and specialized industrial equipment, with no mainstream automotive production since the . Custom builds, such as modified V16 installations in vehicles, highlight their appeal for enthusiasts seeking unparalleled smoothness and , though broader adoption is curtailed by emissions hurdles and the rise of electric alternatives.

Advantages and disadvantages

Key benefits

V16 engines exhibit exceptional , characterized by minimal and levels, owing to their balanced firing intervals and effective of inertial forces in the V configuration. This design allows for overlapping power impulses that distribute events evenly across the , resulting in a refined operation suitable for luxury vehicles and high-speed applications where occupant comfort is paramount. The configuration also enables high , permitting outputs exceeding 500 horsepower in relatively compact packages, particularly when enhanced by supercharging or turbocharging systems that boost air efficiency without excessively increasing overall size. This compactness arises from the shared and optimized bank arrangement, which minimizes the engine's footprint while maximizing . Torque delivery in V16 engines features a broad , with peak available at low RPMs, facilitating strong and effective load handling across a wide operating range. This characteristic stems from the large total and multi-cylinder setup, which provide substantial low-end pull ideal for demanding needs. further enhances their versatility, allowing straightforward adaptation to larger displacements up to 20 liters in variants without incurring proportional losses in efficiency, thanks to modular V-series designs that maintain balanced performance. Durability benefits from the multi-cylinder , where redundant cooling systems and distributed loads reduce on individual components, enabling extended intervals in rigorous environments. Robust materials and advanced scavenging techniques contribute to low rates, supporting operational lifespans with overhaul intervals often exceeding 10,000 hours in and applications.

Major drawbacks

The V16 engine's substantial physical dimensions and weight have posed significant packaging challenges in . With cylinder banks spanning approximately 45 inches (1.14 meters) in length for historical examples like the Cadillac V16, the configuration often requires engine bays exceeding 2 meters to accommodate the extended layout, including accessories and cooling systems, thereby complicating integration and increasing overall length—such as the 222.5-inch of Cadillac models. This bulk is exacerbated by the engine's weight, typically around 1,300 pounds (590 kg) for the Cadillac V16 with accessories, adding 1,000–1,400 pounds to the 's curb mass and demanding reinforced frames. The inherent complexity of V16 engines, featuring essentially double the components of a comparable V8—such as dual heads, manifolds, and valvetrains—drives up and operational costs substantially. For instance, V16 employed two iron V8 blocks bolted to a shared aluminum-alloy , along with separate carburetors and exhaust systems, resulting in production expenses that made units unprofitable despite prices ranging from $5,350 to $9,200 (equivalent to approximately $90,000–$155,000 in 2024 dollars). This duplication elevates costs relative to V8 counterparts due to increased material use and precision assembly requirements. Fuel efficiency remains a persistent drawback, stemming from the large (often 7.0–7.4 liters) and elevated friction losses across 16 cylinders and extended . Early automotive V16s, such as the Cadillac model, achieved only about 8 under typical conditions, reflecting pumping losses that reduce overall thermodynamic efficiency compared to fewer-cylinder designs. Maintenance demands are heightened by the V16's intricate layout, where access to inner cylinders and shared components like the is obstructed, necessitating specialized tools and labor. The , for example, consumed a quart of oil every 150 miles during extended use, contributing to service intervals that inflate ownership costs beyond those of simpler engines. In the , V16 engines struggle with emissions compliance, as their high and multi-cylinder friction generate elevated and CO2 outputs without advanced technologies like (EGR) or turbocharging, rendering them non-viable under stringent regulations like Euro 6 or EPA Tier 3 standards. Recent hybrid integrations, such as in the 2024 Bugatti Tourbillon's V16, mitigate some emissions issues through , though complexity and costs remain high.

Automotive applications

Production vehicles

The Cadillac V-16, introduced in as the Series 452, represented the pinnacle of luxury engineering during the early [Great Depression](/page/Great Depression) era, featuring a 7.4-liter () overhead-valve V16 engine that produced 165 horsepower at 3,400 rpm and 380 pound-feet of torque at 1,200 rpm. This engine incorporated innovative hydraulic valve lifters for silent operation without periodic adjustments, along with a 5.5:1 and side-rod , all housed in a massive 148-inch available in various coachwork styles from and . spanned from to 1937 across Series 452, 90, and 75 variants, with a total of approximately 3,886 units built, primarily in the first two years before economic pressures reduced output to under 100 annually by 1934. Marketed as a for the elite, the V-16 directly competed with the in the ultra-luxury segment, offering unmatched smoothness and refinement at prices starting around $6,000, though sales suffered amid the Depression. The Marmon Sixteen, launched in 1931 as Marmon's response to Cadillac's V-16, utilized an 8.0-liter (491 ) all-aluminum V16 engine with overhead valves, liners, and a 45-degree bank angle, delivering 200 horsepower at 3,400 rpm through a 6:1 and pushrod . Designed for superior power-to-weight performance in a package—weighing under 5,000 pounds despite its size—the engine featured aluminum heads for efficient cooling and was paired with a three-speed in bodies crafted by LeBaron and others on a 145-inch . Only about 390 units were produced between 1931 and 1933, when Marmon declared , positioning the Sixteen as a rare luxury contender in a shrinking high-end market dominated by established names like and . Its emphasis on acceleration—capable of outpacing many contemporaries—highlighted its role as an engineering showcase for affluent buyers seeking exclusivity during economic turmoil. In the , the emerged as a limited-production , powered by a transversely mounted 6.0-liter (5,995 cc) DOHC V16 engine with four valves per cylinder, generating 540 horsepower at 8,000 rpm and 400 pound-feet of torque at 6,000 rpm via sequential and a 9.3:1 . Built on a tubular steel chassis with aluminum body panels and a five-speed , the emphasized exotic styling by and performance rivaling Ferraris, with a top speed over 200 mph. Backed by music producer , who lent his name for marketing flair, only nine units were completed between 1991 and 1995, with production halting due to the early-1990s despite initial plans for higher volume. Targeted at wealthy collectors in and the , the V16T served as a bold, under-the-radar to and Ferrari in the niche, prized for its unique engine sound and rarity.

Prototypes and concepts

In the early , manufacturers pursued multi-cylinder engines to symbolize luxury and power amid the "cylinder wars." The , one of the "Three Ps" alongside and Pierce-Arrow, developed a single V16 prototype in as a response to Cadillac's V16. This experimental sedan, bodied by , featured a 7.6 L (464.6 cu in) V16 engine with overhead valves, a single , central , and aluminum , blocks, and heads, delivering nearly 175 . Intended to revive the brand's prestige, the project was abandoned due to the Great Depression's economic pressures, with Peerless ceasing automobile production, filing for , and converting its facilities to brewery operations by 1934; the sole prototype survives today at the Crawford Auto-Aviation Museum in . The 2003 Cadillac Sixteen concept revived the V16 layout for modern luxury applications. This show car featured a 13.6-liter all-aluminum V16 engine producing 1,000 horsepower and 1,000 lb-ft of torque, paired with a six-speed in a neo-classical body on a 131-inch . Designed to evoke V-16 while incorporating potential, it showcased advanced and but remained a non-production demonstrator. In the , custom V16 builds emerged in the hot-rod community as accessible experiments with twin-V8 conversions. Enthusiasts often mated two small-block V8s, such as LS engines, to create narrow-angle V16s for dragsters and show cars, achieving displacements around 8.0-10.0 L and power exceeding 1,000 with modern fueling and ECUs. These one-off projects, like those featured at shows, highlight DIY innovation in balancing vibration and performance without factory constraints, though they remain niche due to complexity and cost.

Racing engines

The V16 engine found prominent application in pre-war racing through the Type C, which utilized a supercharged 6.0-liter V16 producing between 520 and 600 horsepower, enabling rear-engine configurations that dominated European circuits from 1936 to 1939. This engine, designed by , featured a 45-degree V angle and Roots-type , contributing to victories in events like the and establishing mid-engine layouts as a competitive advantage. V16 engines remain rare in modern motorsport, with no adoption in Formula 1 due to regulatory constraints on cylinder count and displacement; however, custom builds, including twin-supercharged variants in the , have appeared in climb events for their exceptional . Revived historical units, such as the , continue to compete in climbs, leveraging their high-revving character for steep ascents. Racing V16s typically incorporate advanced tuning, including compression ratios exceeding 12:1 for enhanced and dry-sump systems to sustain engine speeds over 5,000 RPM under high lateral loads. These features, seen in both historical and custom applications, prioritize oil scavenging and cooling to manage the stresses of sustained high-output operation.

Industrial applications

Marine propulsion

The V16 engine has seen limited but notable application in marine propulsion, particularly in high-performance speedboats and modern diesel-powered vessels requiring substantial power in a relatively compact package. In the early 20th century, gasoline-fueled V16 designs emerged for racing hydroplanes, exemplified by the Miller 18.2-liter V16 marine engine developed in 1931. This supercharged unit, featuring a Schwitzer-Cummins Roots-type blower delivering 10 psi boost, produced up to 1,800 horsepower at 6,000 rpm and powered Gar Wood's Miss America VIII speedboat. The twin-engine installation enabled the vessel to achieve a world water speed record of 104 mph on October 25, 1931, demonstrating the V16's potential for extreme performance in lightweight, high-speed craft. Following the post-war shift toward engines for enhanced reliability and in environments, V16 configurations became prominent in commercial and military systems. The MTU 16V 396 series, introduced in the 1970s, represents a key example of this evolution, with variants offering power outputs ranging from approximately 2,300 to 3,400 horsepower depending on the rating and application. These four-stroke, turbocharged diesels operate at rated speeds up to 2,040 rpm and are suited for fast vessels with intermittent load factors, including luxury yachts over 100 feet and patrol boats. Similarly, the 3516C, a V16 with a of 78 liters, delivers 2,000 to 3,385 brake horsepower at 1,200 to 1,800 rpm, making it a -rated option for demanding needs. Key adaptations for marine use include saltwater cooling systems to handle corrosive seawater environments, as seen in the 3516C's gear-driven centrifugal sea water pump and heat exchangers, which maintain optimal temperatures without aftertreatment for emissions compliance. These engines emphasize low-RPM torque for efficient propulsion—such as the MTU 16V 396's high torque at around 1,800 rpm—to drive controllable-pitch propellers, enabling reversible thrust for maneuvering in yachts and craft without transmission reversal. Advanced systems further enhance efficiency, reducing consumption while supporting continuous operation in applications like governmental workboats and high-end superyachts. In marine contexts, V16 engines offer advantages over longer inline-16 designs, including a more compact footprint that fits tighter engine rooms while delivering comparable power density. Their balanced firing order also provides superior vibration isolation, improving passenger comfort in luxury vessels and reducing structural fatigue in military patrol boats.

Railway locomotives

The adoption of V16 diesel engines in railway locomotives accelerated in the , with introducing the turbocharged 16-567 variant in 1954 as an evolution of its earlier 12-cylinder base . This , with 567 cubic inches per cylinder, delivered 2,000 to 2,500 horsepower at around 800 RPM, enabling reliable high-traction power for freight and passenger services in diesel-electric configurations. Prominent examples include the 16-7FDL engine, introduced in the for heavy freight applications, which produced up to 4,300 horsepower in its advanced configurations and became widespread in North American locomotives like the Dash 8 and Dash 9 series. Similarly, 's 16-645, launched in the , offered 3,000 horsepower with uniflow scavenging for improved efficiency and was a staple in models such as the SD40-2. These engines emphasized four-stroke () or two-stroke () designs optimized for demands. V16 engines in locomotives feature design adaptations for rail operations, including high output at low speeds of 800-1,000 RPM to handle heavy starting loads and grades, while integrating with systems that use the traction motors as generators to slow without engine strain. This low-RPM operation, combined with turbocharging, provides sustained power for long hauls while maintaining . These engines played a pivotal role in the post-World War II transition to diesel-electric propulsion, supplanting steam locomotives by offering superior reliability and lower maintenance costs; for instance, the , powered by the 16-645 , became an icon of this shift, with over 3,900 units built from 1972 to for North American freight networks. Today, V16 diesel engines remain in service for heavy-haul freight, particularly upgraded older units from and , with emissions retrofits such as aftertreatment systems achieving partial Tier 4 compliance in the to meet environmental regulations without full repowering.

Stationary power and aviation

V16 engines have seen limited but specialized use in stationary power generation, where their high power output and scalability make them suitable for backup and applications in . These diesel configurations provide robust, continuous electricity for facilities requiring uninterrupted supply, such as data centers and hospitals, often operating in parallel to meet variable loads. The 3516, a V-16, four-stroke, water-cooled introduced in the 1980s, powers sets with ratings from 1,450 to 1,750 ekW at 60 Hz in standby mode, scalable up to approximately 2,000 kW in industrial variants. It supports paralleling of multiple units for enhanced capacity and reliability, ensuring seamless operation during outages in demanding environments like healthcare and facilities. Modern examples include the MTU Series 4000 16V 4000, a high-performance delivering over 3,000 kW in standby configurations, optimized for and low emissions in generation. This engine is deployed for peak shaving in electrical grids, helping balance demand fluctuations by rapidly ramping up output when needed. In , V16 engines have remained exceedingly rare, confined almost entirely to experimental efforts due to challenges with , , and into airframes. Their large and liquid-cooled designs, while offering substantial , often imposed penalties in terms of drag and compared to more compact radial or V12 alternatives. A notable World War II-era example is the Chrysler XIV-2220, an inverted V-16 liquid-cooled engine producing 2,500 hp, developed in the mid-1940s as a potential upgrade for fighter aircraft like the Republic P-47 Thunderbolt. Tested successfully in modified prototypes, it incorporated advanced supercharging for high-altitude performance but was never produced owing to the war's end and shifting priorities toward jet propulsion. Post-war, no major V16 aviation engines reached production, with applications limited to niche prototypes.