These heroes are big twins built with a recipe that is air-cooled, 45 degree angled and longitudinally mounted. . These engines have been named according to the difference in their configuration and appearance of valves.
The reign of 45 degree-angled engine cylinders started in 1909 when the first Harley-Davidson engine was sold. However, it was not successful because the automatic vacuum governed intake valves were designed for only single cylinder engines and gave rise to issues associated with air flow characteristics. After making some minor tweaks in the mechanical intake valve and the location of the valves, the company was successful in making its first successful engine, known as F-head. It saw production from 1911 to 1929.
This was followed by the very popular, Flathead, which had a production run from 1929 to 1939. It was named after its flat shaped piston heads on the top. This engine doesn’t have valves placed on the cylinder head, nevertheless, they are situated at the sides and thus it is known as Sidevalve.
The first of Harley’s overhead valve V-twin, the Knucklehead engine, was seen from 1936 to 1947. The name itself conveys that the shape of the rocker covers looks like knuckles on the fist. It has a re-circulating oil system.
With few alterations in the knucklehead engine, the new Panhead (1948-1965) engine arrived post the World War II. The name Panhead comes evidently from the pan shaped valve covers. This champion has aluminium cylinder heads and hydraulic valve lifters and is the first Harley to feature electric starter rather than a kick start. Legs take a sigh of relief!
The Pan Head
The Shovelhead (1966-1985) engine was a beautiful lion. It replaced the leaky sheet metal used in Panhead with cast aluminium rocker boxes with and extra added spice of Tillotson carburettor and PowerPak which boosted up the power by 15%. You must be wondering, which part can be shovel shaped, right? Well, it’s none other than our cylinder head.
The next Harley engine comes with a lot of nicknames that is Evolution, Blockhead, Evo and stayed till the end of 20th century. This was constructed with steel-lined alloy cylinders and with new pushrods, cylinders heads and even pistons. Though it had the same displacement as the Shovelhead but surprisingly cooked more torque and horsepower.
The Twin Cam 88 starts the era of the present world of Harley engines which is way more powerful, smoother and more reliable than never before. These engines are rubber mounted to isolate the vibration from the rider. The most amazing part is that these engines have twin counterbalances, which are loads, to nullify the engine before it reaches the frame and also makes the frame much stronger. This is fruitful for the rider as well as the bike parts. The compactness of engine with the frame gives a classic look too.
V-Rod was the most different bike that Harley has ever produced. The hand behind this development was not only Harley but also Porsche. This one is so different that the cylinders are separated by 60 degrees and not 45! This allowed lower motorcycle design and increased space for mounting fuel injectors and the air box.The V-Rod
I have decided the moment I start earning on my own, Harley has to be my first investment. The sassy vintage look of Harley is and always will be the trendsetter.