However, since the oil had to be sent all the way up to the heads to do the work, there were quite a few failures, and then the engine would be dead quiet as a result-since it would stop working. In 1948 the hydraulics were up in the head between the top of the pushrods and the rockers arms, with oil pressure serving to keep the gap at the proper clearance this also reduced the noisy valve clatter so noticeable in the Knuckleheads. The new heads had a cover that looked rather like a cake pan, hence the Panhead nickname. New aluminum-alloy cylinder heads were developed, with all the oil lines inside, and these were bolted on the Knuck’s cast-iron cylinders and bottom end. The Knuckleheads had a lot of external plumbing, which resulted in leaks that could easily mess up the rider’s trousers. The engineers decided that the Knucklehead engine’s life could be improved and extended if the factory took care of valve adjustments-with hydraulic valve lifters, as the automobile world was using. Americans, with large spaces and long distances, loved the big, low-revving engines. This was the F, the single letter meaning low compression engine, with the L indicating a middling compression. But for the 1941 model year the unit was bored and stroked to 74 inches (1,208cc), fueled through a 33mm Linkert. The original OHV engine, the E dating from 1936, was a 61 incher, 998cc to be precise, with a 32mm Linkert carb. The bike in the photos is an FL model, meaning it had the big 74-inch overhead-valve motor.
With the Deluxe Buddy Seat came a secondary spring support from a bracket with two springs that attached to the frame and could be raised and attached to the aft end of the saddle-very useful when the passenger was a bit on the weighty side. The front of the saddle hinged on the frame, with the main support coming from a post going down into a frame tube-which had springs at the bottom that could be arranged to suit the weight of the rider(s). The rigid frame had a saddle, solo or optional two-up, which did supply a decent measure of comfort for the rider. As one road-tester put it in August of 1949, the new fork had made the Big Twin into “a marvelous road motor.” A self-styled humorist noted that the look of the massive fork was that of a couple of beer cans.
They were quite simple, really, with long helical springs located in the fork tubes, more than 5 inches of travel, using a high-viscosity synthetic oil for damping and added cushioning effect. Telescoping forks had been around since the late 1930s, were obviously the “coming thing,” and Harley did not want to be left too far behind. Rumor was that The Company had wanted to include the new fork with the new engine in ’48, to give the consumer a big double-whammy of newness, but cooler heads decided to take this a step at a time. In truth, the factory had come up with the design right after the war, but the economics of using up the extant supply of girder forks, and developing a production line for the new ones kept the girders in business until 1949. That changed in 1949, when the first Hydra-Glide appeared-with a hydraulic telescoping fork.
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