The Golden Anniversary KH Sports and KHK Super Sports were big news for Harley Davidson and the motoring public. The popular Model K now evolved into the KH and later the KHK with many improvements. Foremost was the increase in engine size from 45.12 to 54.2 cubic inch displacement. This was achieved by increasing the stroke from 3-13/16″ to 4-9/16″ (4.562). To the best of my knowledge these were the longest stroke factory built Harleys to date. The flywheels are still available from Truett & Osborn in Wichita, Kansas. The new flywheels utilized tapered shafts and crankpins with retaining nuts, a much stronger system than the previous straight, pressed type. New rod bearing retainers were added for greater reliability. Engine cylinders were made taller to match the stroke increase and had redesigned ports and bigger intake valves. The KH had bigger cams and the KHK had the even larger racing type KK cams. These cams were larger than the ones in Brad Andres` 1955 National Championship KR Motorcycle. The KHKs were hand built factory Hot Rods that also benefited from extensive additional port work and head machining. The headwork increased flow and made room for the valves necessary due to the high-lift cams. Valve springs were changed to the KR racer type. A new Linkert M-53A1 carburetor was added to the package. All this translated into a motorcycle that now produced 38 Horsepower and 1/4 mile dragstrip times were over two seconds quicker than the standard K. The KH would now do the 1/4 in 14.75 seconds. I don`t have performance figures for the KHK but obviously they would be even better.
Now I would like to point out that several books often portray the K as being a sub-standard motorcycle, (in the power department), and not really even being acceptable until it received Overhead Valves and was called an XL. However a 1966 XLH took 15.5 seconds to do the 1/4, although a 1958 XLCH would run it in 14.25. The first Sportster in 1957 had only 7.5 to 1 compression and 40 Horsepower, then the 1958 was upgraded to 9 to 1 with bigger valves. Also the 58 XLCH was a lightweight stripped down motorcycle. No battery, etc. The point I`m making is that granted, the first year K was no rocket at 16.8 seconds but all the other ones, KK, KH, and KHK Models were quite fast motorcycles. Even with its` battery, full fenders, large FL type headlight, huge gas tank and full tins the KH was only a half a second slower than the XLCH. I wonder what numbers the KHK would produce? I feel the K`s deserve a lot more recognition for performance than they ever normally receive.
To compliment the extra power the clutch was enlarged from five disc to seven. The primary cover was consequently wider. The cases were strengthened in various places. A stronger primary chain tensioner was made. Second and third countershaft gears were strengthened and received direct oiling. In 1955 countershaft 3rd and mainshaft 2nd gears were superceded to stronger ones and could be returned to HD for credit. Unfortunately due to the torque of the stroker many of them never had a chance. (Compared to state-of-art Andrews gears these early K gears look like they were formed out of a CheezWhiz can) The clutch gear was fitted with a Torrington bearing in place of the bronze bushing previously used. The cam, primary and countershaft covers were all factory polished. A one-way valve now returns excess primary oil to the crankcase. Speedster handlebars, an option in `53, come standard with the Buckhorns optional. The front forks now have rubber boots covering the tubes instead of chrome covers. The seat has been re-designed and is similar to the Model 165. The brake shoes went from aluminum to pressed steel construction. The lining-type has been changed. A new oil-pressure switch was used. With the solid engine sprocket standard, a new-design compensating sprocket was available as an option. 1952 and 53 frames were recognizable by their hollow foot peg mount tubes. For 54 they are solid. Also the rake and trail was slightly changed and the steering neck beefed up for better stability. The gas tank emblems were the same but the extra trim was all dropped. The rear shock absorbers now had chrome covers and tops in place of the Royalite plastic ones. The front fender carried a 50th Anniversary Medallion on top in front. Facts and figures on the KH: The gearing was as follows. Engine sprocket-30, Clutch- 59, Countershaft-22 and Rear Wheel-49 teeth. Gear ratios were 1st- 11.55, 2nd- 8.35, 3rd- 6.37, with a final 4th- 4.58 to 1. Standard tires and wheels were Goodyear or Firestone 19″ by 3.25″ front and rear. Optional at no extra charge were the same combinations in 18″. For a slight additional charge you could order a Goodyear Grasshopper 18″ by 4.00″ on the rear only. Ignition timing was 19/64″ BTDC & 11/32″ BTDC for the KH & the KHK respectively, with the spark fully advanced at the twist grip. The Cold Valve Tappet Clearance is .004″ intake and .006″ exhaust. Golden Anniversary KHs and KHKs were available in the following standard colors: Pepper Red, Glacier Blue, Forest Green, Anniversary Yellow and Daytona Ivory. For no extra charge the tanks could of been ordered with one color and the fenders another. The new KH and KHK motorcycles were headline making motorcycles, representing the best of 50 years of Harley Davidson producing fine American motorcycles.