McCulloch was a manufacturer of small 1, 2, 4 and 6 cylinder 2-stroke engines for industrial and aeronautical use. Some have been adapted for small ULM and experimental aircraft.

"A list of small McCulloch engines"

-Others have been built for its exclusive aeronautical use from the beginning and its most important application has been in Bensen gyro planes, in target aircraft since the early 1940's, in RPOVs, drones, etc.

-In 1972, McCulloch Motors Corp. of Los Angeles was sold to Northrop-Ventura, which was the successor company to Radioplane Corp., manufacturer of radio-controlled airplanes since the 1940s. It ceased in the late 1980’s.

-The motors listed above are the industrial ones used in motor pumps, chainsaws, etc.

-By contract with Righter for the armed forces, the 4-cylinder model 4300 (Military O-88) was made.

-Its 4300C version gave 65 HP at 4,100 rpm and its life was from 1945 to 1952. it was used on the Radioplane YOQ, OQ, KD2R series target aircraft.

“4318A”

The 4318A, with 4 cylinders gave 72 HP and had a carburetor with two wing nut positions driven by a solenoid. In this way it was possible to control the engine rotation with remote signals.

“4318A”

-Another view of the same engine is shown above. It had the Military designation of O-100-1.

-The B version of the same engine was known as the O-100-2.

“6318”

The 6-cylinder 6318 (O-150-2) gave from 110 to 145 HP

-The same turbocharged engine is shown below. It was the TC-6150.

“TC-6150”

-This engine would give 120 HP. The Military specification was O-150-4.

-Of the initial list there are other small engines that reached military use, the MC-10 was the O-10-1, giving 25 HP.

-The MC-90 was the O-90-1.

-The MC-101 was mounted on the Le-Rotec-Rallye ULM, with 125 cc of displacement and a power of 12 HP.

-McCulloch MC-75 engines that gave 10 hp were installed on a rare Bensen gyroplane, (with a total of 8 engines: 6 for the main rotor in two lines of 3 and two in the tail) and each engine with its own fuel tank.

“Lippisch”

An O-110-1, 72 HP as shown below has been mounted on the Lippisch X-113. And the Good-Year “Inflatoplane” was also powered by a McCulloch engine.

“McCulloch 4318C”

-For helicopters and gyros like the Bensen Giroplane, the 4318C, 60 HP version was made with forced cooling air by means of two belt-driven fans. This was necessary in case of stationary flights.

From Appendix 6: An interesting showcase at the CombatAir Museum in the USA shows us a McCulloch model 0-100-1 with a series of photographs and explanations about its use in target aircraft.

“McCulloch 0-100-1 showcase”

-But what attracts the most attention from the showcase is the top central photograph, in which we see a very young Marilyn Monroe, actually Norma Jeane, who worked at Radioplane Corp., next to an engine at the end of WWII.

“Marilyn's photos”

-From the main text we know that this brand is dedicated to small horizontally-opposed piston engines for general and sports aviation, but its military use has been the most important, especially installed on target aircraft for AAA practices.

“Typical 60 HP McCulloch”

-But the opening of this extension of the brand's chapter is due to the discovery of an atypical McCulloch engine with opposed pistons (Junkers style).

"The Weird McCulloch"

-We see two extreme crankshafts on both sides. With three cylinders and six pistons. It works with the two-stroke system and with ports on both sides of the piston stroke limits.

-Injection occurs through the intake duct in front of the valve, but not inside the cylinder. Its power was 120 HP.

"Efficiency is guaranteed by rotating the mixture"

“Nice looking compact engine”

-In the "Popular Mechanics" magazine there appears an engine with two pistons in each cylinder. This engine already appears in Appendix 5 of this A-Z edition, but it is now new due to the different position of the components, with both pistons close to the BDC.

-It is brought here for a better study of this engine.

"The original McCulloch layout"

-Original arrangement or not, because it turns out that Beardmore, SPA, especially Junkers and ultimately Dair (Diesel Air) did. See all of them.

From Appendix A7/6: Traditionally they have been very light engines for target aircraft, pilotless aircraft, UAVs, motorized gliders, etc.

"Proven Lightness of the McCulloch"

-Weighing only 40 lbs it gave 25 HP with four horizontally-opposed, air-cooled cylinders.

"McCulloch installed on a motorglider"

-It has been essential to open a new entry of this brand, in addition to the one that already exists in this same Amendment 5, because something exceptional has been found: an amazing two-stroke and five-cylinder radial.

-It was installed and tested on Cessna aircraft like in the pictures we show below. The engine is referenced as the McCulloch TSIR-5190.

“McCulloch TSIR-5190, on a Cessna single-engine”

"And at the rear of a Push-Pull"

-In the latter illustration it is installed on the Cessna 337 Push-Pull.

-We see this small 5-cylinder, water-cooled radial from its left side with its oil and fuel filters, a propeller shaft elevation (it seems to reduce little or no speed) by belts and the five-piston injection pump for the gasoline.

-It gives 270 HP with 190 cu. in. of displacement.

-The engine has a turbocharger and variable pitch propeller.

-In the illustration below we see the large radiator and the cutaway engine.

-In the upper front area are the magnetos.

"The interesting TSIR-5190"

-At the rear we see the harmonic exhaust ducts.

-The TSIR reference is supposed to be for TurboSupercharger, Injection and Radial.

-The displacement has the 5 added in front of it for the 5-cylinder engine.

From Appendix 10: Before, during and after the Second World War, the McCulloch company made small engines for target aircraft and “drones”.

The two-stroke, horizontally-opposed cylinder engines are known, which have already been published in the main text.

-There are mentioned other engines resulting from the experimentation laboratory such as TSIR-5190.

“The TSIR, uncovered”

“A currently restored TSIR-5190”

-The TSIR-5190 was a design from the year 1963. The place where it was developed was called "McCulloch Advanced Development Division".

-In 1968 a similar engine was made. It was a Diesel engine known as TRAD-4180 with turbocharger and intercooler.

“Another restored TRAD-4180”

"Schematic drawing of this engine with some values"

-It works with the two-stroke cycle. The cylinder has the intake ports just above the piston's BDC and slightly above the exhaust port.

-The exhaust gases go to the turbo, its compressor sends the pressurized air to the exchanger and to a mechanical blower, and from there to the cylinders.

“TRAD-4180 at the PIMA Museum”

-It had four radial cylinders in "X". Above the cylinder head there are the high pressure injectors.

-This engine first entered this A-Z edition as a steam engine called McCollough, by mistake, although the information was taken from a prestigious publication.

-It was subsequently corrected in the main text.

"Detail of a possible installation"

From Appendix 12: Color photo of a model of this brand. In the absence of a carburetor and ready to receive a coat of red paint on the center block.

"Observe the bulbs on the block for the connecting rods"