Lister Petter is a British company that manufactures internal combustion engines for industry.
It was formed in 1986 from the merger of Petters Limited and R A Lister and Company. At that time the company was part of the Hawker Siddeley group, but today L-P is independent. Its products are small diesel engine market, ranging from single-cylinder air-cooled engines of 2.7 horsepower (the 'Zeta' series) up to the 64 horsepower (48 kW) 'Delta' engine. One higher-power engine of up to 335 horsepower (250 kW), the 'Omega' is also produced under licence. The engine designs range from more recent design high-speed turbodiesels (such as the 'Gamma' or 'Omega' engines) to traditional single-cylinder medium-speed types such as the 'A-Series' and 'Phi' types.
Contents |
Lister Petter engines are generally used in stationary industrial applications such as pumping and electricity generation. The company produces a range of complete generator sets, units equipped for welding and in-house pumping sets, as well as supplying engines to other equipment manufacturers. L-P engines are widely exported, especially for use in irrigation projects. The company also maintains a long tradition (of both its founder companies) in supplying engines for marine applications both as prime mover engines for small vessels and as auxiliary power units in larger ones.
Lister Petter's main product, the 'Alpha' series of sub-2-litre engines, is also available in spark ignition forms for running on natural gas or propane. L-P also manufactures and sells biodiesel plants, allowing customers to produce their own fuel for diesel engines.
Lister & Petter engines were workhorses of the British Commonwealth; many of these engines are still in use today in dump trucks, generators and water pumps. They generally, but not exclusively, leave the factory in a Mid Brunswick Green colouring.
One of the most popular early Petter engines was the AVA series, AVA1 and AVA2 (1- and 2-cylinder engines respectively), and the Lister D. The majority of these engines were hand-crank start and fully mechanical, without any electronics or electrical controls. Engines like this, if not still working, are now considered collectors' pieces.
Widely used examples of later models include the LT series, often used in single-cylinder form to power small cement mixers, and the ST series, a popular engine for canal boats. They too were large and heavy engines with low power outputs, low operating speeds and extremely robust construction, capable of reliable operation for years even under the conditions of abuse and neglect of maintenance found in their typical construction-site applications.
A particularly successful model was the A range; these engines were much smaller and lighter than earlier models, although still extremely robustly constructed. Plant powered by an A-range engine is often light enough to be lifted and carried by two workers, instead of requiring a wheeled chassis, which is a great advantage on a construction site. The A range is particularly suitable for powering small generators of around 4-5kVA output. Unlike earlier designs it is capable of running at up to 3600 rpm and can therefore generate mains-frequency AC using a two-pole alternator; the lower operating speed of earlier designs mandates the use of a four-pole alternator, which is much larger and heavier for the same output power.
In the writers opinion the Petter A range can be problematic especially in the raw water cooled marine version known as the Petter Mini-6. The problem is that the aluminium heads corrode rather badly in salt water and head gaskets are rather troublesome. Frequently water will leak out of the engine into the boat. Special head nuts can be obtained that will allow a slightly higher torque to be used and special high temperature black RTV silicon sealant can be used on the water jacket. If possible use a genuine Petter gasket (old type that has asbestos reinforcement) In jellyfish infested waters a large basket type water strainer and an engine overheat alarm are must-haves as without these items one can easily have an engine fire (the rubber exhaust hose catches fire and the silencer melts) After an engine fire the head gasket WILL need replacing. There was also a freshwater cooled Petter Mini-6 that was made for Westerbeke but these are extremely rare in Europe. The good points about the Mini-6 are its compact size and low weight (it is smaller than the Japanese market leader and it can be used to replace petrol engines without overloading the boat) If the Japanese engine will not fit one can replace the Petter with the Farryman Yellow River Star, however the cost is quite considerable. Another solution is to change the cylinder barrel and head for the highly reliable air cooled versions but this fairly popular method is more suitable for an open boat or workboat. Some marine Mini-6 engines were air cooled from the factory.
Starting an engine like this involves switching the Bryce Berger injection pump to excess fuel mode and lifting the decompressor (this held exhaust valve open) to allow the engine to turn over without compression. The engine is then turned over at a steady pace until 10/15 clicks from the injector are heard; these clicks are a result of the spring & needle of the injector jumping with each injection of diesel at a relatively slow speed as the engine may only be doing 60-70 rpm. This now means there are 10/15 injections of diesel sitting in the combustion bowl on top of the piston. The engine is then turned over much faster, and when the engine had lots of momentum the decompressor is flung down; this means on the next compression stage the pressure in the cylinder becomes so great that the temperature rises to a point that the diesel bursts into flames. Once the first combustion cycle has taken place this gives the engine more momentum until it is over-revving, at which point the excess fuel lever automatically drops off and the engine sits at its governed idle speed.
The smallest A-range models such as the AA1 were available with rope start - a sheave was attached to the flywheel and the engine started by pulling on a rope wound round the sheave. This requires a particular technique to obtain the "clicks" from the injector and prime the combustion chamber with fuel. The decompressor is not used; the engine is rotated to just after top dead centre (TDC) on the intake stroke, then the starter rope is pulled with a nicely judged amount of force calculated to give the engine just enough momentum to raise the piston against compression pressure to the point where the injector operates, at around 20 degrees before TDC, but not so much that the engine carries on past TDC. Instead the compression pressure takes over and reverses the rotation, turning the engine backwards to its starting point and rewinding the rope onto the sheave; effectively the engine is "bounced" off the compression pressure. This is repeated several times until a sufficient number of priming injections have been made; then the starting rope is given a mighty heave sufficient to carry the engine over compression and hopefully cause it to fire. If the heave is not sufficiently vigorous the engine will not fire and the whole process has to be repeated from the start. The method requires considerable amounts of both strength and skill.
Some engines are equipped with a "cold starting aid" comprising a pipette incorporated into the oil dipstick which allows a few ml of lubricating oil to be taken from the crankcase, and a removable plug through which this oil can be injected into the inlet manifold. This aids starting in three ways: the oil improves the low-speed sealing ability of the piston rings and valves - especially in a worn engine - thereby ensuring that maximum compression pressure and hence temperature is achieved; the volume of oil injected is a significant fraction of the combustion chamber volume, so the volume at TDC is reduced and the compression ratio increased; and lubricating oil has a lower ignition temperature than diesel fuel, so less extreme conditions are required for the first combustion event.
Electric starting was an option for most of these engines except the smallest A-range models. Electric start models were fitted with a starter motor and a flywheel generator - a set of magnets embedded in the flywheel which induced current in a set of coils in the flywheel housing - to recharge the starting battery. It was never a very popular option. The cost of the engine was significantly more than the hand-start models; the starter motor and the large lead-acid battery added significant extra weight; the flywheel generator was not very effective, and flat batteries were common; the vibration for which these engines are notorious tended to damage the battery and shorten its useful life; the electrical components were not as robust as the "hewn from granite" engines, and did not stand up well to the harsh operating conditions of the construction site applications for which these engines were frequently used{{Citation needed|date=August 2011. Electric starting was therefore fitted relatively rarely, mainly to the larger engines and especially to engines powering generators, where the lack of robustness of electrical apparatus was a problem that had to be lived with in any case.
The company's headquarters and manufacturing facility are in Dursley, Gloucestershire, formerly the headquarters of R A Lister and Company. Lister Petter have agents in France, the USA, China and India, which market their products and carry out final assembly of larger items such as generating sets from imported parts.