Circa-1986 Petter Diesel Generator

By Staff
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Courtesy of Gas Engine Magazine Staff
Circa-1986 6-1/2hp Petter AC1 Diesel Generator

Circa-1986 6-1/2hp Petter AC1 Diesel Generator

Manufacturer: Lister Petter Ltd., Hardwicke, England
Year: Circa 1986
Serial No.: 50263
Horsepower: 6-1/2hp @ 3,604rpm
Bore & Stroke: 3in x 2.625in
Compression ratio: 18.51:1
Ignition: Compression ignition diesel w/direct injection
Governing: Throttle
Cooling: Air
Generator Output: 2,900 watts, 120v/240v

Harold Sohner is a retired engineer living in the Texas Hill Country. In the mid-1970s, he worked for the Collins Radio Co. in Dallas, Texas. One of the programs he was responsible for was establishing a microwave communication system along Egypt’s Mediterranean coast. Eight stations were installed and the energy for each was supplied by a battery bank charged by a generator. The generators were powered by Petter engines. The durability and reliability of these engines made a lasting impression on Harold and the other engineers involved.

Old man in a white cap sitting at a white table in an pink chair.

Later, in retirement in a rural area, Harold wanted to have a backup system to support the electrical system in his workshop. Upon learning that his friend Richard Kepler Sr. had a small Petter diesel engine for sale, he purchased it and belted it to a generator that could be tied to his workshop’s electrical system to maintain the building’s heating and lighting systems in the event of a power outage.

Harold’s Petter engine is a compact unit – 17.9 inches long, 17.2 inches wide and 17.9 inches high. It weighs 103 pounds. It is an AC1 (Series 2) engine, number 50263, and a member of the A Range, which includes engines AA1, AC1, AC1 (Series 2), AD1 and AD2. It was built some time after Jan. 1, 1986.

The engine develops 6-1/2hp at 3,604rpm. The single-cylinder, air-cooled engine has a 304cc capacity, with a 3-inch bore, a 2.625-inch stroke, and 18.51:1 compression. The engine has a direct-injection fuel system. A 5.4-quart fuel tank is engine mounted. At a 75 percent load of 2,500rpm, the engine is rated to consume 1.9 pints of diesel fuel per hour. The crankcase holds 2.9 quarts of lubricating oil. The engine is equipped with an electric starting system.

An indication of the engine’s durability is that the company recommends that the engine be considered for a major overhaul after 5,000 hours of operation.

Lister Engines

Lister-Petter engines have a long and distinguished history, dating back to 1867, when Robert Ashton Lister established R.A. Lister and Company in Dursley, England. The firm manufactured agricultural machinery. Towards the end of the century, the company attained considerable success manufacturing and selling milk churns and wooden barrels for butter, sheep shearing machinery and the Alexandra Cream Separator developed by Danish engineer Mikael Pedersen.

Close up view of the kill switch with a small red sign that says Run,…

In 1909, the R.A. Lister Co. acquired the rights to manufacture gasoline-fueled engines based on the designs of engines produced by the Stover Manufacturing and Engine Co. in the United States. Large numbers of these engines were produced for the British government during World War I. In 1926, lightweight narrow-gauge railway locomotives were developed for use in brickworks and on peat bogs, and the Lister Auto-Truck was introduced to move materials around factories, railroad stations, shipping docks, etc. Production of locomotives ceased in 1968; Auto-Trucks were produced until 1973.

The Lister Co. introduced its own design of a “CS” (cold start) diesel engine in 1929 – the Lister 9-1. It was a single-cylinder engine and produced 9hp. In 1930 the 5-1, 10-2, 18-2 and 38-4 engines were issued. These were followed by the 27-3 in 1931 and the 3-1 CD and CE engines in 1933. All were painted Brunswick Green.

Lister’s CS engines were popular choices for powering electric generators, irrigation pumps and other agricultural and industrial machines. Many were exported for use in countries worldwide.  The slow-running engines were noteworthy for their longevity and reliability; some ran continuously with only minimum maintenance for years or even decades.

The control panel for the generator unit (above) and the cylinder head, with the glow…

By 1936, the Lister Co. manufactured 600 designs of diesel and gasoline engines in 80 different sizes and types – most of which were small engines producing 1-1/2hp to 3hp. The most successful Lister engine was the D-type, introduced in 1931 and built until 1964. Over 250,000 D-type engines were produced. Most were 1-1/2hp models and were used with pumps and electrical generators. In 1963 the SR, SL and LD models became the company’s primary products.

View above the kill switch. showing hoses and pipes going in one part of the…

The R.A. Lister Co. Ltd. was a family-run business until it was acquired by the Hawker Siddeley Group Ltd. in 1965.  At that time the company was producing a wide variety of products, including gasoline engines, diesel engines, diesel marine engines, electrical generators, pumps, Auto-Trucks, tractor loaders, cream separators, milk coolers, butter churns, sheep shearing machines, horse and cow clippers, farm elevators, tractor rakes, combine haymakers, side-delivery rakes, swathe turners, fertilizer broadcasters, harrows, insecticide applicators, and garden furniture. Most of the products produced were exported to other countries. Lister Ltd. was merged with Petter Ltd. in 1986.

Petter Engines

The Petter’s automotive-style starter.

James B. Petter was an engineer in Yeovil, England, a district in South Somerset. In 1870, his father gave him an ironmongery firm as a wedding present. He later acquired a foundry. In 1893, Petter’s twin sons Ernest and Percival developed a self-propelled oil-fueled engine. In 1895, they invented the first internal-combustion powered motor car in the United Kingdom – the Petter, Hill and Ball’s Autocar. It had a 3hp twin-cylinder horizontal engine. In 1895 they also introduced a 2.5hp oil engine for agricultural use and in 1897 they produced a combined oil engine and pump.

The Petter’s small fuel tank is fine as the diesel engine only sips fuel.

Ernest and Percival purchased James B. Petter and Sons Ltd. from their father in 1901. They quickly expanded the range of their Petter Standard engines from 1-1/4hp to 30hp. These were high-quality open crankcase engines. In 1902 they introduced an agricultural tractor with a 30hp diesel engine. The Handyman engine was also issued in that year to compete with engines being imported from the United States. The Handyman cost 80 percent of the price of Petter Standard engines and could only be purchased in quantities of 50.

The Petter’s large, automotive-style muffler keeps things quiet (above).

In 1910 the company registered as a public company – Petters Ltd. The company produced both 2-stroke and 4-stroke semi-diesel engines. Petters engines included the M-type (gasoline), the S-type (diesel) and air-cooled diesels such as the PA21, the AV and AA1. The S-type was a cold-starting engine. The last 2-stroke engine, the SS, was produced in 1938. It harnessed exhaust gases to create a vacuum that sucked in air; this functioned somewhat like a supercharger. It also featured a low-temperature oil-cooled piston. The SS was available with two to six cylinders (125hp-375hp) and was used in British locomotives. In 1928 the Atomic line of 2-stroke full-diesel engines was introduced; this line included engines from 5hp to 480hp. By 1936 the Petters Co. was producing 4-stroke engines.

The Petter may not win any beauty awards, but it’s a compact, efficient unit.

In 1912 Petters Ltd. moved into a new factory in Reckleford. The Vickers factory was purchased in 1919 and the company was renamed Vickers Petter Ltd. Vickers Petter Ltd. joined the Associated British Oil Engine Co. in 1937, and this group, in turn, was later acquired by the British Electrical Group. In 1949 Petter was sold to J.&H. McLaren and Co. The Hawker Siddeley Brush Group Ltd. purchased Petter Ltd. in 1957 and divided the company into four subsidiaries – Petter Staines (small engines), the Petter Generator Division, the Petter Marine Division and the Thermo-King Division.


Lister-Petter Engines

The Hawker Siddeley Group Ltd. acquired Petter Ltd. in 1957, and the R.A. Lister Co. in 1965. Lister and Petter were merged in 1986 to form Lister Petter Ltd. During the decade from 1992 to 2002, decreasing sales and a downturn in the economy resulted in  Hawker Siddeley and its subsidiaries going through a series of sales and mergers. Hawker Siddeley was purchased by BTR in 1992. BTR decided to sell off Hawker Siddeley’s subsidiary operations, and in 1996 the sheep shearing equipment business was sold via a management buyout. Large engine production was acquired by Deutz AG, and small-engine production in Dursley was sold to Schroders Venture Capital Ltd.

The Petter’s generator has a rated output of 2,900 watts, 120 volt or 240 volt.

Schroders Venture Capital decided to sell Lister-Petter because of continued declining sales, and the company went through a management buyout in 2000. This was made possible by the sale of the original Lister factory in Littlecombe to the South West Regional Development Agency. Sales continued to decline and the company was forced to file for bankruptcy in 2003. A management buyout backed by the South West Regional Development Agency enabled the company to continue in operation. Unfortunately, the company failed again in 2006, and was again forced to file for bankruptcy. After restructuring, production remained at Dursley, but the registered headquarters was moved to Hardwicke. When the company failed again in 2013, production ended in Dursley and was moved to Hardwicke in the county of Gloucestshire. Parts supply was housed in a former Royal Air Force hangar at Aston Down.

The generator’s color-coded outlets

During this period of economic turmoil, small, durable, and reliable industrial and marine engines such as the T Series of 1-3-cylinder air-cooled engines and the ALPHA series of 2-5-cylinder water-cooled engines were the company’s primary products. The OMEGA, a new heavy-duty engine, was offered in 2007.

The EGL Group Sleeman Hawker acquired Lister-Petter in 2019 and production continues at Hardwicke. The company manufactures generator sets, welders, pumps, biodiesel plants, and agricultural, construction, and emergency equipment. Diesel, natural gas or propane-fueled engines are popular in foreign countries to power irrigation systems. The company also produces marine engines used as primary power units in small ships and for auxiliary power in larger vessels. The company has sales and assembly plants in a number of other countries such as France, the United States, China, and India.

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