The Chrysler XIV-2220 (XI-2220 from 1944) was an experimental 2,500 hp, 2,220 cubic inch (36.4 liter) liquid-cooled inverted- V-16

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years ma ...

Chrysler Stellantis North America (officially FCA US and formerly Chrysler ()) is one of the " Big Three" automobile manufacturers in the United States, headquartered in Auburn Hills, Michigan. It is the American subsidiary of the multinational automotiv ...

starting in 1940. Although several aircraft designs had considered using it, by the time it was ready for use in 1945 the war was already over. Only a few engines were built during the program, and it retained its 'X' designation the entire time as the XIV-2220, later XI-2220. The IV-2220 is historically important as it was Chrysler's first

hemi Hemi may refer to: People Surname * Jack Hemi (1914–1996), New Zealand freezing worker, rugby union and league player, shearer * Ronald Hemi (1933–2000), New Zealand rugby union player Given name * Hemi Bawa, Indian painter and sculptor * ...

, a design that would re-appear for many years later and is now a Chrysler

trademark A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from ot ...

Design and development

Original design

Chrysler had apparently been carrying out paper studies of a very large engine for a brief period starting in May 1940 and decided to present their work to the

United States Army Air Corps The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical r ...

. They proposed a large engine to provide 2,500 hp initially, with room for growth upwards. Instead of using advanced features such as

sleeve valve The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truc ...

s for improved RPM, they instead decided to use a larger number of "normal sized" cylinders in a V-16 arrangement. The Army was interested, and sent them a development contract tender on June 22, 1940, to which Chrysler responded on July 2. The extremely long profile of the new design meant that the crankshaft would be highly loaded if power was taken off at the propeller end. Chrysler's solution to this problem was unique; power was instead taken from the middle of the engine, placing the propeller reduction gear in a gap between two V-8 cylinder banks and sending power to the front of the engine via a long extension shaft running below the crankshaft. Additionally many of the accessories were driven off the drive shaft instead of the crank shaft. This solution also raised the weight of the engine by the amount of the shaft, but it was apparently a price worth paying. A single overhead cam drove the two-per-cylinder

poppet valve A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usua ...

s, arranged at an angle to the piston in a hemi-spherical cylinder head, with the spark plug arranged between the valves. This arrangement allowed for "cross-flow" scavenging of the charge, and had been used on various race and performance car engines for some time.

Problems and advantages

One early problem for the design was the lack of high-strength aluminum alloys; the original supplier,

Alcoa Alcoa Corporation (an acronym for Aluminum Company of America) is a Pittsburgh-based industrial corporation. It is the world's eighth-largest producer of aluminum. Alcoa conducts operations in 10 countries. Alcoa is a major producer of primar ...

, was able to deliver only half the required strength. Chrysler was able to address this through much improved production-line

quality control Quality control (QC) is a process by which entities review the quality of all factors involved in production. ISO 9000 defines quality control as "a part of quality management focused on fulfilling quality requirements". This approach place ...

, but the engine was nevertheless built with considerably more distance between the cylinders than normal, making the engine relatively long. This was not helped by the "gap" holding the propeller gearing in the middle of the engine, or the large accessories section at the end. The IV-2220 was comparatively huge; the

Rolls-Royce Griffon The Rolls-Royce Griffon is a British 37- litre (2,240 cu in) capacity, 60-degree V-12, liquid-cooled aero engine designed and built by Rolls-Royce Limited. In keeping with company convention, the Griffon was named after a bird of pre ...

of about the same displacement was 77 inches long, while the IV-2220 was 122. Weight was not greatly affected, however, and the

power-to-weight ratio Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measuremen ...

was certainly competitive at 1.03 hp/lb. Some of this was no doubt due to the use of a

turbocharger In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

in addition to a

supercharger In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced indu ...

for more continuous boost and less power draw on the engine. Turbochargers are generally "free," powered not by the engine directly as in a supercharger, but by otherwise wasted exhaust energy. The IV-2220 also included a fairly advanced liquid-cooled

intercooler An intercooler is a heat exchanger used to cool a gas after compression. Often found in turbocharged engines, intercoolers are also used in air compressors, air conditioners, refrigeration and gas turbines. Internal combustion engines ...

between the turbocharger and supercharger, and an aftercooler behind the supercharger as well. This complex arrangement resulted in excellent altitude performance, keeping maximum rated power all the way to 25,000 ft. The engine first flew on 26 July 1945, mounted on a converted P-47D-15-RE which was intended to serve as the prototype for the new P-47H series using this engine. A second example followed, but the war was already over and the need for a new engine in the

Jet Age The Jet Age is a period in the history of aviation defined by the advent of aircraft powered by jet turbine engines, and by the social change this brought about. Jet airliners were able to fly much higher, faster, and farther than older pisto ...

was gone. The only other design to select it was the Curtiss XP-60C in 1942, but the engine was so delayed that the P-60 moved onto other engines.

Specifications (XIV-2220-11)

''Note: some sources claim the engine delivered 2,300 hp in testing, and that 2,500 was the design power. Chrysler documents specify 2,500 hp, the figure used here.''

References

* Chrysler specification sheet from the collection of Kimble D. McCutcheon, president of th
Aircraft Engine Historical Society
* *

External links

{{US military piston aeroengines Chrysler engines 1940s aircraft piston engines