“Eugenio Barsanti, an Italian engineer, Worked with Felice Matteucci an helped invented the first real internal combustion engine in 1853. In 1860, Belgian Jean Joseph Etienne Lenoir produced a gas fired internal combustion engine. In 1864, Nikolaus Otto patented the first atmospheric gas engine. In 1872, George Brayton invented the first commercial liquid fueled internal combustion engine. In 1876, Nikolaus Otto, working with Gottlieb Daimler and Wilhelm Maybach, patented the compressed charge, four-cycle engine. In 1879, Karl Benz patented a reliable two stroke gas engine. In 1892, Rudolf Diesel developed the first compressed charge, compression ignition engine”. There where was no compression on the first piston engines instead that ran on air fuel mixture sucked or blown in during the first part of the intake stroke. The most significant distinction between modern internal combustion engines and the early designs is the use of compression of the fuel charge prior to combustion. The problem of ignition of fuel was handled in early engines with an open flame and a sliding gate. To obtain a faster engine speed Daimler adopted a Hot Tube ignition which allowed 600 rpm immediately in his 1883 horizontal cylinder engine and very soon after over 900 rpm. Most of the engines of that time could not exceed 200 rpm due to their ignition and induction systems Today, The engine shaft spins at 2900 rpm on a walk behind mower. The first practical engine ran on illuminating gas (coal gas). In 1883, Daimler created an engine that ran on liquid petroleum a fuel called Ligroin which has a chemical makeup of Hexane-N. The fuel is also known as petroleum naphtha. Otto’s first engines were push engines which produced a push through the entire stroke (like a Diesel). Daimler’s engines produced a rapid pulse more suitable for mobile engine use. Internal combustion engines require ignition of the mixture either by spark ignition or compression ignition. Before the invention of reliable electrical methods hot tube and flame methods were used. Experimental engines with laser ignition have been built. The aluminum engine were introduced in the mid 1950s so the engines could be lighter for applications such as rotary lawn mowers. After five years that Improved it with the introduction of the Kool Bore that means it is fully made of aluminum and there is also Sleeve Bore made with aluminum with an cast iron cylinder liner. The easy spin starting was an compression release, added as an extra hump on the intake lobe of the camshaft, that was introduced in 1961 to reduce the effort required of starting an engine. In 1982, a new U.S. federal safety regulation required lawn mower blades to stop routing within three seconds of letting go of the handle (it’s was before the time of riding lawn mowers). The least costly and the most common way of complying with these new regulation was to put a flywheel brake on the flywheel, so it would stop the engine (and therefore the blade at the same time) immediately as the handle was released. The Briggs and Stratton engineers found engines with the Easy spin camshaft were really difficult to restart after being braked to a quick stop. The easy spin lobe hump was moved to the exhaust valve, but this reduced the engine performance. The intake side easy spin remained in use on the Briggs and Stratton’s engines larger than those used on mowers subject to the brake requirement, it was discontinued in 1997 due to the tightening emission regulations. The synchro balanced engine This was a 1966 innovation designed to attenuate the vibration caused by the reciprocating mass of a single cylinder engine. These design was a series of counterweights opposing fo the crankpin. The twin cylinder engine this engine was introduced in 1977 as a means of competing with Briggs and Stratton’s rivals, particularly Japanese firms like Honda who were cutting into traditional Briggs and Stratton markets by producing lawn mower engines (and later, complete lawn mowers). These first models were rated 16 hp (11.9 Kilowatts or kW, they are a metric unit used to measure power 1 hp = 0.7457 kWs) and displaced 40 cubic inches (656 cubic centimeters or cc, is a unit of volume 1 cubic inch = 16.3871 cubic centimeters), it was joined in 1979 by the 42 cubic inch models that rated at 18 hp. The original price for the 16 hp version was $70 lower at U.S. $228 than their single-cylinder cast-iron version bearing the same power rating. Industrial Commercial a series of engines, initially ranging from 3 to 20.5 hp, introduced in 1979 as Briggs and Stratton’s answer to high quality commercial duty engines produced by there competitors. These engines include heavy duty features such as Stellite exhaust valves, upgraded bearings, an cast iron sleeved cylinder bores and high capacity air cleaners. Briggs and Stratton hybrid in 1980, at the tail end of the energy crisis, Briggs and Stratton developed the first gasoline electric hybrid automobile. “The Hybrid (made by combining two different elements)” designed by Brooks Stevens and powered by a twin cylinder 16 hp Briggs and Stratton engine and a large electric battery. Magnetron ignition this solid state ignition system that was introduced by Briggs and Stratton in 1982. By eliminated the points and condenser system, the performance of which steadily degraded between required periodic maintenance service. Magnetron was made available for retrofitment to Briggs and Stratton engines made in or before 1963. Competitor Tecumseh had made a capacitor discharge ignition setup in 1968 for their cast iron engine models, expanding its availability and making it standard equipment on the vertical shaft engines powered lawn mowers in the late 1976s, five years before the advent of the Briggs Magnetron. Defunct competitor Clinton Engines commercialized a piezo “Spark Pump” ignition without breaker points in the early 1960s.In 1883 when John Michael applied enamel to a cast-iron horse trough to create the company’s Kohler Co.first bathtub. Small engines used to be made of cast iron (Cast iron block, flathead, with Gravity feed float carb unless otherwise noted) but in mid 1950s that became Aluminum and then in the 1980s that had Industrial or commercial models (whatever you what to call them) Aluminum dissipate heat a lot faster than iron, which is why none of the manufacturers will make cast iron small engines any longer, the high cost of iron and the fewer places. Pure iron is very expensive now of days, and recycling the old iron just does not make the cut for good engines components. Hense an cast iron sleeves that are now the must have for high horsepower small engines. The pressed in the sleeve gives the cylinder wall the durability that is needed, the aluminum block heat dissipation needed along with making it a much lighter small engine. The crankshafts and cams are still cast iron for the durability. Some of the smaller horsepower small engines use Nikasil (Nickel alloy) coated cylinder walls instead of iron liners. GM tried this stuff in a car engine once with the first Vega 151 4 cylinders, and it failed horribly, but it works ok for low hour cheap small engines. Bearing technology has become much better in recent decades, and is one of the factors and that is why it is not uncommon for an automobile engine to run 200k miles now of days, where it was rare for one to go to 100k miles just 30 years ago. a Briggs aluminum small engine with nikasil coated cylinder walls go much past the 400 hour mark, these are the under 10 HP ones. aluminum cylinder bores without liners were pioneered in the 70’s in the Chevy Vega. By making the interior of the bore have a higher silicon content (by casting cooling rates), the dissimilarities between the piston and cylinder prevent galling and seizing. That being said, it must have been a tricky process because junkyards were soon full of seized up aluminum block Vegas. The other thing to remember is that these are CHEAP and DISPOSABLE engines. Probably loose sloppy tolerances play as big a role in preventing seizure as anything else. you can usually tell if the engine is a cool-bore or a iron sleeved engine by pulling the cylinder head and looking around the edge of the cylinder to the top of the engine, if it looks like a ring that’s pressed into the block then it has an iron sleeve, another way to tell is by finding a simple magnet, if the magnet sticks to the bore, then the engine has a sleeve in it, if the magnet don’t stick, then its a cool-bore, and the other obvious identification of what bore the engine has is that it will say on the front of the engine shroud. if it doesn’t say anything but the engine name and horsepower than more then likely it’s a cool-bore, but if it says the engine name and horsepower and has an I/C on the shroud aswell, I/C stands for industrial commercial and all industrial commercial engines have pressed in iron sleeve cylinders in them. Briggs tended to make I/C engines with a steel or iron sleeve just for that exact thing, industrial use. The IC engines used ball bearings on the crank, had a cast iron cylinder liner, and more often than not a mechanical governor. The Cool Bore engines had plain aluminum main bearings, an aluminum bore, and an air vane governor. One note about your engine if it is over 3 1/2 HP – check the oil level with every fuel fill up. 5 HP and up engines have such a large swept area in the cylinder, that they tend to burn oil, even though you don’t see smoke. I will say this – the cool bore engines will take a lot of abuse, and keep running. Water cooled automotive engines run at much cooler temperatures, and have a lot less thermal expansion, than air cooled engines. For the same reason, that’s why honing deglazing is necessary in automotive engines. The heat and wear generated by the slightly roughened surface, is what seats in the rings. An air cooled engine runs at 5 to 6 hundred degrees hotter than a 180 auto engine, so the chrome rings provide enough wear to reseat the ring assembly, without removing too much material from the cylinder walls.