$19,900
Santa Monica, California
Category
Standard Motorcycles
Engine
1000
Posted Over 1 Month
Beautifully restored by a marque expert! 1948 Ariel Square Four 4G Engine Number: CJ146 In 1928, engineer Edward Turner was shopping a new motorcycle design to English manufacturers. BSA turned him down, but Ariel was interested. The engine was an unusual four-cylinder. V-twins and inline fours, set both lengthwise and across the frame, had been used previously but Turner’s new design had two vertical twins sharing a common crankcase. The cylinder barrels were cast as a unit in a monobloc design. Their two crankshafts were joined by a flywheel and rotated in opposite directions. By having the two pistons of one crank at top and bottom dead center and the pistons of the second shaft at half stroke, the design was ingeniously compact and the firing order made it practically vibration free. The Ariel Square Four 4F made its debut at the 1930 Olympia Motorcycle Show featuring an overhead camshaft 500cc with a hand shift for the Burman gearbox, which was integral with the crankcase. Overhead camshafts and unit construction were well into the future for most firms, so Ariel was a real pioneer. Few knew then that the bike would become a legend of the British industry, both for its performance and dependability. The latter was underscored by the Square Four’s widespread used in the British law enforcement community. Improvements were continuous during the Square Four’s 28-year production run. In 1932, the 4F was taken out to 600cc, although the 500 remained available. The next year, a 4F 600 fitted with a supercharger lapped the famous Brooklands speed bowl at 110 miles per hour. The 4G was introduced in 1936 with a new 996cc overhead-valve engine. To accommodate the larger displacement, a new crankshaft was set in a much stronger crankcase. These years saw the British economy recovering in the run up to World War II, and Square Fours were seen on the road more often, where they were known as the “Monarch of the Multis”, referring to their multi-cylinder engines in a sea of British singles and twins. By the immediate post-World War II period, the 4G had a plunger rear end and telescopic front forks. To date, the innovative Ariel Square Four remains unique in motorcycling history; a true 'gentleman's motorcycle, this refined yet characterful machine retains an enthusiastic and loyal following, and is now a greatly appreciating classic, highly pri zed by discerning enthusiasts. The example of Ariel’s “iron head” offered here has been in the long-term ownership of a former engineer and motorcycle collector. A pet project, the bike started as a ratty barn find and was subject to a full restoration with a few modifications. At the heart of the bike is a motor fully rebuilt by marque expert Chuck Walton. Chuck’s tally now exceeds 110 engine builds and so to say he is an expert of the Ariel breed is just scratching the surface. His knowledge is encyclopedic and having restored so many engines, understands every pitfall of the unique design and precisely how to prevent engine failure. Tricks to rod bolts (a well-known weak point of the engine), rocker arms, crank bushings, valve guides and springs ensure engines with great power, superb reliability and great longevity. The engine is mounted in its original and unmodified, unmolested frame, fully restored with a fresh powdercoat finish in black. All cycle parts have been restored or refurbished. The result is a bike that starts easily and idles well. It has the enormous grunt of a Square 4 of 1000cc and sounds great. It runs cool and strong, shifting well with a good clutch. Brakes and suspension work very well for an old British bike. This is a great opportunity to acquire an increasingly rare piece of British history and style.
