1956 Harley-Davidson FL

“My friend, Matt Olsen (of Carl’s Cycle Supply in Aberdeen, South Dakota), knew about the Panhead and called to tell me about it,” Paul explains. “He sent me some photos, and it piqued my interest — even though it was a bit later than I usually like, but I’m a 1956 model myself.”

Paul prefers motorcycles built prior to 1949 and has several machines in his collection including a 1930 Henderson KJ, a 1936 Harley-Davidson Knucklehead and a 1937 Brough Superior SS100. He lives 50 miles from his office, and often commutes aboard one of his antique motorcycles — they have to run and be reliable.
“The Panhead was reasonably priced for a bike that was described as being in original condition, with little wear on anything, right down to the rubber components,” Paul says. “Although I’d only ever seen photos of it, even if it wasn’t as good as it looked, I still thought it was a good buy.”

And indeed, it was. After HaulBikes dropped it off, Paul let the Panhead sit for a month or two as he assessed what he had. “The bike was absolutely beautiful,” he explains, and continues, “All of the parts were in great shape, simply because it had sat since 1960.”

Engine progression

Well known for their flathead V-twin engines built during the teens and 1920s, by the early 1930s Harley-Davidson knew it had to build an overhead valve power plant in order to remain vital in the motorcycle marketplace. Engineers were tasked with designing an OHV V-twin with pushrod-operated valves and a recirculating oil system. Although times were tough for the Motor Company during the Depression era, funds continued to be allocated to the OHV project and by 1933, prototype engines were being constructed. Although still something of a work in progress, in 1935 at a dealer meeting, Harley-Davidson showed the new 61 cubic-inch OHV motorcycle as the model E and the hotter model EL. These are the bikes that were later referred to as Knuckleheads, thanks to their distinctively shaped rocker box covers. Sales started off slow, but customers soon found their way into Harley-Davidson showrooms, and by 1941 engine capacity had been increased to 74 cubic-inches to create the F-series.

After World War II, returning servicemen were eager to get aboard new motorcycles. According to author Mitch Bergeron in his newly-released The Harley-Davidson Source Book: All the Milestone Production Models Since 1903, “The Motor Company wanted to meet the growing demand, but it also wanted to deliver a better machine. Even though the Knucklehead set the template for Harley’s overhead valve motorcycles, it fell short in controlling the oily mess created by the rocker-cover system. This is not to say the Knucklehead was a bad machine; it was a beautiful bike, but it had some major issues that had to be addressed, including overheating and oiling problems. With the war over, the engineers at Harley put their efforts into designing a better top end, among other things, for the new 1948 models.”

Harley-Davidson worked with what was essentially the Knucklehead bottom end. This featured vertically split cases that housed cast iron flywheels sandwiching fork-and-blade connecting rods on 1/4-inch caged roller bearings, and the entire crank assembly rotated on roller main bearings. On top of this, Harley-Davidson placed a new top end. Dispensing with the previous model’s cast iron cylinder heads that were prone to overheating, Harley-Davidson installed aluminum heads. These new alloy heads were well-finned to promote better heat dissipation, but that aluminum also brought greater expansion that would affect proper valve lash.
To compensate, Harley-Davidson opted to automatically maintain valve clearances by revising the pushrods and adding hydraulic tappets to the tops of the rods. Pressed steel D-shaped rocker covers that looked like upside down pans — hence, the Panhead nickname — went on top of the cylinder heads. Between the pan-shaped covers and the heads were new rubber sealing rings that helped keep oil inside the rocker area.

To further improve lubrication, a better oil pump was added, while new internal passages ensured adequate oil flow. The Motor Company continued to offer the E series with its 3-5/16in x 3-1/2in bore and stroke and the F series with its 3-7/16in x 3-31/32in bore and stroke. Cylinders, too, remained cast iron, and were secured to the cases via four studs and nuts while a four-lobe cam inside the timing chest worked the overhead valve gear. The 4-speed constant-mesh transmission was the same, and for the first year of the Panhead, so too was the springer front end. A slightly revised rigid frame, with curved “wishbone” shaped double front downtubes, was employed to hold the Panhead engine.

For 1949, a hydraulic front fork was added to the model. Harley-Davidson referred to the fork as the Hydra-Glide, but eventually, all Panhead models built between 1950 and 1957 were dubbed Hydra-Glides. In his Source Book, Mitch Bergeron writes, “The Panhead engine was significantly improved in 1950 with revised cylinder heads that featured larger intake ports for enhanced power output. In 1951, The Motor Company eliminated base F models with their medium compression engines. The FLs (Sport Solo models), with their higher-compression engines (7.5:1) served as the new base models.”

He continues, “By 1952, sales of the Model “E” had dropped to below 1,000 units, and the company decided to drop it from the 1953 lineup. The model’s problem was pricing: the FL retailed for $995 in 1952, so riders could step up to the 74-cubic-inch Model FL for just an additional $15.”

Improvements continued to be made with revised cases in 1953 and new hydraulic lifters and rollers that went to the bottom of the pushrods, a location that provided improved oiling for theses lifters. By 1956, the year R.L. bought her Panhead, Harley-Davidson had switched the frame from curved front downtubes to straight ones and introduced the model FLH. The H, in Harley-Davidson nomenclature, denoted a higher compression ratio with 8.0:1 pistons. The Motor Company also improved the cylinder heads with revised intake ports and added a hotter camshaft with higher lift.

By 1958, Harley-Davidson had installed a swingarm to provide rear suspension and dubbed the machine the Duo-Glide. Panhead engines were employed through the Duo-Glide’s run, and the first-year of the 1965 electric-start Electra Glide. In 1966, a new cylinder head and rocker box design that became known as the Shovelhead was added to the Panhead bottom end.

The 1956 Harley-Davidson that R.L. purchased was the FL model with its 7.5:1 compression ratio, as opposed to the 8.0:1 of the FLH.
“It had remnants of gas and oil in it, and the tires were the ones that would have been installed at the factory,” Paul explains. “It was a time capsule, and the dilemma was, do I continue to let it sit the way it is, or do I ride it?”

Decisions, decisions

Paul is good friends with Bill Rodencal, Harley-Davidson Museum Motorcycle Restorer/Conservator, and although he doesn’t solicit extra work, he did offer to take a look at the Panhead. Between Paul and Bill, it was decided it would be best to sympathetically “resurrect” the Harley-Davidson, simply cleaning and servicing but making sure the motorcycle could ultimately be ridden.

“Bill took it completely apart,” Paul says, “and when he got into it, he found everything was packed with red Kansas clay, from the inside of the taillight to the carburetor. It was all cleaned up and put back into service, with the exception of the fuel shut-off valve. That was the only thing we had to replace, besides the tires and tubes, which I’ve kept.”

As purchased, the Panhead was equipped with a dual saddle known as a Buddy Seat. This was replaced with a period correct solo seat. The windshield plastic was badly discolored, so the clear and blue panels were replaced but all of the original hardware was retained. On the speedometer, which had frozen up over time, the needle had faded. While the instrument was taken apart and cleaned, Paul decided to leave the needle as it was.

Without knowing the real history behind R.L.’s Panhead and some of the special features that had been added to it, Paul says it’s easy to make up a story, but it’s one that makes some sense.

“Our theory is, the guys at her Harley-Davidson dealership liked her, and helped her upgrade the bike over time,” Paul says. Items such as the parking lights, tucked under the rear seat with their red lenses, were available in the Harley-Davidson accessory catalog for around $5. The heel/toe foot shift lever was also a Harley-Davidson add-on. The headers are Superior True Duals, and the mufflers are from a later Duo-Glide.

Paul adds, “You can see on the mufflers where they’ve been changed. There are small creases where the clamps held them on a different bike, and they look like take-offs that her Harley-Davidson dealership put on her bike at some point.”

The Atomic Blue and Champion Yellow paint is completely original, right down to flaws from the factory. For example, a yellow thumbprint from a Harley-Davidson employee was found in a spot where it couldn’t be seen until one of the gas tanks was removed.

After being resurrected, Paul had the Panhead back in his collection early in 2019. He rode it some of that year, but not at all in 2020. In 2021, he added 1,200 miles to R.L.’s Harley-Davidson.

To start the Panhead from cold, Paul’s drill is to rotate the left hand grip to retard the ignition timing, put the choke lever all the way down, and open the throttle wide. Then, he gives it two firm kicks. After that, he moves the choke lever to the first position, turns the throttle until it is one quarter open, and turns the ignition on. With one kick, it starts, and then Paul fully advances the spark. After it is warm, simply turning on the ignition and kicking it once brings it to life.

Although R.L.’s first name will likely remain a mystery, Paul says he’ll be taking good care of her Panhead. “I basically have the privilege of breaking in a 1956 motorcycle,” he says, and adds, “It will remain in my collection, and I’ll continue to use it.” MC