Engines - Various

The United States declared war on Germany on April 6, 1917. The Aircraft Production Board, then headed up by Howard E. Coffin of the Hudson Motor Car Co. and his assistant Edward A. Deeds, a major stockholder in Delco, set the basic parameters for what would come to be known as the Liberty. The new engine would be lighter and slightly more powerful than the Rolls-Royce Eagle. Modular construction, employing common cylinder and valve components, would slash development time and permit the engine to be used on all types of airplanes from trainers to heavy bombers. And all this would be accomplished within the strictures of a conservative design philosophy.

The first of many expedients was to telescope layout into a two-day (some say five-day) marathon at the New Willard hotel in Washington, DC that begun in the afternoon of May 31, 1917. At General Pershing's request, the L-8 was put on hold in favor of a 12-cylinder L-12 that would be more powerful than existing Allied engines. The first of these was tested in August, 1918.

The 45º cylinder angle raised questions about torsional vibration. Robert J. Raymond demonstrated that the L-12 crankshaft underwent severe torque peaks at 1,333 rpm, 1,714 rpm and 2,000 rpm. Any of these inputs could result in failure. Raymond quotes two studies dating from the 1930s that indicate the presence of torsional vibration at certain operating speeds. One of these studies described Liberty crankshaft breakage as "epidemic."

The Liberty had other faults. C. Fayette Taylor, who was in a position to know, reported that half of the early production engines could not pass the 50-hr acceptance test. Burnt exhaust valves and, as has been pointed out, accessory-gear failures were common on all versions.
TBO, or time between overhauls, is the primary measure of durability. By 1926 Navy L-12s were averaging 75 hours between overhauls. Newer air-cooled engines had TBOs of 300 hours

Once the war ended, the problem became what to do with the engines, for which few airframes were available. Some were donated to the Air Mail Service and vocational schools, and others were sold as surplus for pennies on the dollar. Rum runners found that 400 hp gave them an advantage over Coast Guard cutters. Still, by 1924, 11,810 L-12s remained in inventory, enough to satisfy military needs for 26 years.

Although the Liberty had very limited application for military aircraft, the overhang made it difficult to justify acquisition of newer and more expensive power plants.

Attempts to convince commercial operators to adopt the engine on economic grounds failed. It vibrated, weighed more than it should, and had a reputation for unreliability. Army mechanics did their part by foregoing overhauls. When an L-12 needed work, they replaced it with a new one. That practice continued until 1929.

Used on the 1924 Douglas World Cruiser

enginehistory.org Notes on the Liberty Aircraft Engine

(Wikipedia) - Liberty L-12

Used on: Fairchild 24

The Warner Scarab is an American seven-cylinder radial aircraft engine, that was manufactured by the Warner Aircraft Corporation of Detroit, Michigan in 1928 through to the early 1940s.

Super Scarab SS-50/50A - Increased cylinder bore to 4.625 inches to develop 145 hp (108 kW) at 2,050 rpm from 499 cu in (8 l) with a dry weight of 303 lb (137 kg).

(Wikipedia).com - Warner Scarab

Warner Engine Company

Three cylinder radial engine built in Holland, Michigan. The O.E. Szekely Corporation of Holland was founded in 1928 to build light aircraft and engines. They were used to power small aircraft such as the Rearwin Junior, Taylor H-2 and American Eagle Eaglet. Often criticized for reliability issues and design flaws many were replaced with better engines in their original airframes. Few examples still exist.

The cylinders had a tendency to break off in operation and the cable around them was an attempt to prevent that from happening. There is no record of how successful that was.

hollandsentinel.com
Szekely-aircraft-topic-of-Vintage-Car-Club

(Wikipedia) - Szekely SR-3

Szekely SR-3

Allison engines were built first for the Bell Aircobra during WWII. Used in Curtis P-40s in the Aleutians.

(Wikipedia) - Allison V-1710

The Franklin 4 (US military designations O-150, O-170, O-175, and O-200) was a series of air-cooled aircraft engines of flat-4 configuration produced in the 1930s and 1940s.

4-cylinder air-cooled horizontally opposed aircraft piston engine

(Wikipedia) - Franklin 4 Series

The LeBlond 90 is a 5-cylinder air-cooled radial aircraft piston engine produced in the 1930s.

(Wikipedia) - LeBlond Aircraft Engine Corporation

(Wikipedia) - LeBlond radial engines

The E-113 was a small flat-twin piston engine developed by Aeronca for use in some of their light aircraft. It was an overhead valve development of the flathead configuration E-107.

Certificated in April 1931, the Aeronca E-113 was an outgrowth of the Wright-Morehouse engine and was designed again for light aircraft. Considered highly reliable, it was the most powerful two-cylinder engine of its time. The E-113 first powered the Aeronca C-1 Cadet aircraft in 1931. It was also used in the Aeronca C-2 and C-3 aircraft. The C-3 was widely used for student instruction in the 1930s.

Originally fitted with a single ignition system, this was uprated to dual ignition when changes in FAA regulations made this mandatory in 1939. By that time, however, both the engine and the aircraft that it powered were facing obsolescence. Altogether, some 1,800 examples were built. Following an incident in October 2015 where the propeller detached from an Aeronca C3 in 2015, the Light Aircraft Association has issued an advisory that all aircraft fitted with these engines have the crankshaft attachment inspected prior to flying again. This issue has been recognised since 1939.

(Wikipedia) - Aeronca E-113

The Aeronatica Corp of America, founded in November of 1928, built the first light aircraft for the General Aviation market. Their C-2 and C-3 aircraft were very popular during the depression because of the low purchase price and low cost of operations.

At the time, there was on really reliable small aircraft engines so the Aeronatica Corporation, the name was change to Aeronca in 1941, designed and built their own. The first one, the E107 was rated at 26 horse power, only a small number was built. The E113 followed and was rated at 36 horse power.

Production ended in 1938, primarily because better, more reliable and higher horsepower engines had become available. You came only do so much to raise the horse power of a 2 cylinder engine to, and the CAA had mandated dual ignition for all aviation engines. Aeronca designed a dual ignition system for the E113 but it proved to be unreliable.

• Built 2/7/42
• 200 hp with 7.5:1 compression ratio
• 6 cylinder inline inverted air-cooled
• Used in Grumman Widgeon, Fairchild PT-19 and PT-26.
• ASM 92-21-9

(Wikipedia) - Ranger L-440

airandspace.si.edu - Ranger L-440

Fairchild entered the aircraft engine business in 1925 with the formation of the Fairchild-Caminez engine corporation of Farmingdale, New York.

The L-440-1 completed its 150-hour military type test in June 1939.

The Ranger L-440 (company designation 6-440C) are six-cylinder inline inverted air-cooled aero-engines produced by the Ranger Aircraft Engine Division of the Fairchild Engine and Airplane Corporation of Farmingdale, New York, United States. The engine was mainly produced for Fairchild's family of training aircraft in the mid-1930s.

The advantages of inverted engines included improved visibility for the pilot, improved access to cylinder heads and manifolds for the ground crew, having the centre of mass of a multi-bank engine lower in the engine, and having the widest part of a multi-bank engine being closer to the midline of the fuselage, which is also generally wide.

McCulloch Motors Corporation of Los Angeles, their first aircraft product apparently was the production from 1943, under US Government contracts, of Righter-designed two-stroke cycle engines for WWII target drones.

The Model 0-100-1 Engine is a four-cylinder, opposed-type, air-cooled engine which operates on the conventional two-cycle principle. It is designed primarily to furnish power for propulsion of radio-controlled pilotless aircraft for target or guided missile purposes.

Used in Radioplane OQ-19D

Three pictures from miniairboatassoc.com:

(Wikipedia) - McCulloch Motors Corporation

enginehistory.org - McCulloch

combatairmuseum.org - McCulloch 0-100-1 Drone Engine

miniairboatassoc.com - McCulloch-0-100-1-Drone

Turbojet aircraft engine

The Fairchild Engine Division (previously the Ranger Aircraft Engine Division of the Fairchild Engine & Aircraft Corporation) began development of the J44 in 1947. It was used in target drones, missiles, and as jet boosters on several aircraft types.

ASM 92-21-2

(Wikipedia) - Fairchild J-44