Harley Museum – The ExhaustNotes Blog

Potato Potato Potato

By Joe Berk

Love them or hate them, there’s something about Harley-Davidson motorcycles that command attention, and during our recent visit to the Harley museum in Milwaukee, one of the exhibits that grabbed my attention was The Engine Wall. It had a magnificent display of Harley-Davidson engines including their big twins, their small twins, and other engines in the Harley family tree. I always found the evolution of the big twin engines mildly confusing, but this dramatic display cleared all that up. I grabbed a photo of each one and I thought I’d share them with you here on the blog.

F-Head (1911-1929)

The F-head engines were 61 cubic inches, and later, 74 cubic inches. These were Harley’s first v-twin engines, and they featured an inlet over exhaust valve configuration. What that means is that the intake valve was an overhead valve contained in the cylinder head (it moved down to let in the air-fuel mixture), and the exhaust valve was a side valve (or flathead valve) contained in the cylinder on one side (it moved up to allow the exhaust gases to escape). Inlet over exhaust internal combustion engine configurations (or F-heads) were fairly common in the early days of gasoline engines. If you draw the arrangement schematically, it sort of looks like an F (hence the name). The larger of the two Harley F-head models produced 11 horsepower.

V-Series Flathead (1930-1936)

The V-series flatheads were either 45 cubic inches or 74 cubic inches. They were sidevalve engines, which means the valves and their seats faced up and were located in the cylinders (not the cylinder heads), alongside piston (hence the sidevalve descriptor). This allowed the head to be basically flat (when viewed from the bottom), and that’s why these engines are called flatheads. It’s an old school design and it works well, but due to the twists and turns the intake and exhaust gases have to make and their poor heat dissipation, flatheads are limited in how much power they can produce. Harley would get around to fixing that in 1936 with the introduction of their overhead valve Knucklehead engine, but that would be down the road. Read on; we’ll get to that.

U-Series Flathead (1937-1948)

This was the second iteration of Harley’s sidevalve (or flathead) engines. There were two versions: The U and UL models (both had 74 cubic inches), and the UH and ULH (these had 80 cubic inches). The U series of engines were used for both motorcycles and Harley’s three-wheeled vehicles.

Knucklehead (1936-1947)

The Knucklehead was the first of Harley’s overhead valve engines, and the knucklehead name was derived from the valve covers’ appearance. Knuckleheads were made in a 61 cubic inch model and then in 1941, a 74 cubic inch configuration.

I’ve read that Knucklehead engines had serious oil leak issues caused by an overly complex rocker box cover (something Harley tried to correct with the next engine configuration, the Panhead). Knuckleheads had cast iron cylinder heads, which tended to make them run hot (cast iron does not dissipate heat very well). The Knucklehead motorcycles were the first Harleys that featured their distinctive Big Twin style, something that Harley has kept right up to present-day offerings.

Panhead (1948-1965)

The Panhead Harleys got their name from the valve covers’ appearance (they look like pans). This engine and the Evo engine (the engine that appeared two iterations later) are, in my opinion, the two best looking engines Harley ever made. In a major design shift for Harley, Panhead cylinder heads were made of aluminum, which improved heat dissipation and temperature control. The Panhead was intended to improve performance and address the oil leak issues associated with the Knucklehead. Did it work? I don’t know. I’ve never seen a Panhead Harley that did not leak. They sure are beautiful, though. The Panhead had a short production run, but it had a major impact on Harley styling.

The last year of the Panhead (1965) was the first year Harley had electric starting (that was when Harley introduced the Electra Glide name). My two ultimate dream bikes are the 1965 Harley Electra Glide and the Norton P-11 (which is discussed elsewhere on ExNotes). In my opinion, Panhead Harleys are exceptionally beautiful motorcycles.

Shovelhead (1966-1984)

1966 saw the introduction of another Harley engine, and yet another name based on the rocker box appearance.

I had a Shovelhead (a 1979 Electra Glide Classic). It was so bad I called it the Optical Illusion (because it looked like a motorcycle). My shovelhead Electra Glide was the worst motor vehicle of any type I ever owned (car, motorcycle, lawn mower, and Cox-.049-model airplane). It was constantly plagued by oil leaks and breakdown. It wouldn’t go a hundred miles without something breaking. After coming off a Triumph Bonneville, the Harley handled like a garbage truck. It would hang an exhaust valve every 4,000 miles, and as it was explained to me by the dealer, it was because when unleaded gasoline was introduced in the US, the valves would stick in the valve guides without the added lubricity provided by leaded gas. I don’t know if that was the reason or not, but in 12,000 miles, that bike needed three valve jobs (the first two were on the dealer with the bike’s 12,000-mile warranty; the third was on me because the bike had just over 12,000 miles. After paying for that last valve job, I sold my Electra Glide and I swore I’d never buy another Harley (but I did; see below). It was beautiful, though, and I wish I had kept it.

Evolution (1984-1999)

Harley got their act together on this one, and it was probably because they subcontracted the engineering to Porsche. Willie G drove a Porsche, and he knew they knew how to engineer engines. It was a good move. I had a ’92 Heritage Softail and it was a great motorcycle. My dealer? Not so much, but I guess it was all part of the Harley experience. I put a lot of fun miles on my ’92 including trips all over the US Southwest and Mexico, and I enjoyed riding it. The engine style was great, too.

In my opinion, the Evo engine was one of the two best-looking motors Harley ever made (the other was the Panhead; see above).

Twin Cam (1999-2017)

The thing most amazing to me about the Twin Cam engine was that Harley kept it as long as they did. It was basically a bust. Plagued by mechanical failures and overheating from the get-go, one had to be either ignorant or a masochist to buy a Harley with a Twin Cam motor. Cam failures, lubrication failures, and overheating were a fact of life if you owned one of these. The rear cylinder overheating issue was so bad that Harley incorporated a switch and an automated feature to shut down the rear cylinder if the engine got too hot. Amazingly and amusingly (at least to anyone with any mechanical smarts), Harley called activation of the rear cylinder shutdown feature their “parade mode,” with the implication that it was intended to accommodate riders who rode in, you know, parades. There were kits available to shield the riders’ legs from the intense heat the rear cylinder generated.

Twin Cam Rushmore (2014-2016)

This is a higher performance version of the Twin Cam engine that involved many changes, the most significant of which was liquid cooling for the cylinder heads on the Ultra Limited, CVO Limited, and Tri-Glide models (the models in which the radiators could be hidden; you can’t have a Big Twin Harley looking like a Gold Wing, I guess).

Milwaukee Eight (2017 to Present)

Harley joined much of the rest of the world in 2017 when they incorporated four valves (two intake, two exhaust) for each cylinder. Let’s see…two cylinders, four valves per cylinder…that makes eight, and Harley’s hometown is Milwaukee. Hey, the Milwaukee Eight! (At least the name makes more sense than the Rushmore mentioned above.) These engines had problems and Harley had recalls to address them. Wet sumping was a major issue, as was overheating. The Milwaukee Eight incorporated a plastic intake manifold, too, which also had issues. I like the name, though.

I thought the Harley Museum’s Engine Wall was very, very well done. Harley put a lot of thought and work into it, and as a mechanical engineer and former Harley owner, I enjoyed it. There’s the obvious: the actual engines on display. And then there’s the subtle: the slight tilt of that orange wall toward the visitors so that the engines were presented not an angle, but straight on as you tilt your head up to view the different engines. The colors are classic Harley: black, orange, and chrome. It’s one of the better displays I’ve seen of any type in any museum. The whole thing just works. Harley got The Engine Wall right; they did an awesome job.

As mentioned at the start of this blog, there were more engines on The Engine Wall. These included their smaller engines (for the Sportsters and the racebikes), their singles, and some interesting other twins. Keep an eye on ExNotes; we’ll show those, too.

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World War II Harleys

By Joe Berk

Harley-Davidson built four military motorcycles during World War II: The WLA, the WLC, the Knucklehead EL Overhead Valve, and the XA. The 45-cubic inch V-twin WLA was the preferred US Army motorcycle, and it was the motorcycle Harley-Davidson produced in mass quantities. We recently visited the Harley-Davidson Museum in Milwaukee, where I was able to grab most of the photos you see here.

The WLA

The WLA Harley-Davidson (if you haven’t tumbled to it yet, the “A” in WLA stands for Army) used a detuned 750cc air-cooled engine. The motorcycle had a springer front end and a solid rear (there were no springs or shocks in the rear, other than the spring beneath the seat post). The WLA, like other Harleys of that era, had a foot-operated clutch on the left and a hand shifter on the fuel tank’s left side.

The Harley- Davidson WLA. This 45- cubic-inch V-twin was the U.S. Army’s principal motorcycle during World War II (photo provided by the American Motorcycle Historical Foundation). This photo is in my book, Police and Military Motorcycles.

Simplicity was the WLA’s defining theme. Its flathead engine could be disassembled using only hand tools. At the army’s request, Harley built the WLA with a carburetor that had nonadjustable needles and jets, a configuration Harley used on some of its police motorcycles. The idea was to prevent soldiers (or police officers) adjusting the carb. The WLA didn’t even have a key. A trooper just had to kick-start it and ride.

A US Army WLA on display at the Harley Museum. It’s authentic.

The Army quickly found WLA improvement opportunities. Travel on dusty roads tended to accelerate engine wear, so Harley added a monstrous oil-bath air filter. The second improvement was the headlight location. WLA headlights were initially above the handlebars (like on the civilian models). Part of the Army’s tactical doctrine, though, included a move that required the rider to use the motorcycle as a shield. The drill in that move involved skidding the rear wheel, flipping the rear out, and then laying the bike down to form a barricade…you know, so you could shoot at the bad guys from your now-prone motorcycle (thus giving new meaning to the time worn “I had to lay ‘er down” and similar expressions). The problem here was that the above-the-handlebars-headlights often broke during this maneuver. Harley remounted the headlight just above the front fender to better protect it.

The Army started buying WLA Harleys even before the United States went to war. In 1940, the Army ordered 16,000 WLAs to be delivered in 1940 and 1941, and then after Pearl Harbor, the pace increased. Harley won contracts for 13,000 WLAs in 1942, 24,000 in 1943, 11,000 in 1944, and more than 8,000 in 1945.

A United States Navy WLA in Navy gray. Note the headlight location above the handlebars.

Even the Navy got in the act with a WL variant painted sort of a battleship gray. The Navy used their motorcycles for shore patrol duties (the Shore Patrol was the Navy’s Military Police function). I saw one with a sidecar at the Harley Museum in Milwaukee. It was a sweet-looking motorcycle.

Harley-Davidson sold 88,000 military motorcycles during the war to the United States, England, Canada, China, India, and Russia. Many were eventually sold to the public. Most are in collections; some are still ridden today. In addition to the 88,000 complete motorcycles, Harley built enough spare parts to build 30,000 more motorcycles.

The WLC

During World War II, the Canadians also bought Harleys for their army, as did many other countries. The other countries used the standard WLA, but Canada had its own unique requirements. These included an auxiliary hand clutch, interchangeable front and rear wheels, and a front wheel stand (the U.S. model had the traditional Harley side stand). Harley-Davidson built 18,000 WLC motorcycles for Canada.

The 61 EL

Harley had introduced its 61-cubic-inch EL Knucklehead engine to the civilian market in 1936. The Knucklehead and its overhead valve engine offered better performance than the flathead 45 W-series Harleys. Harley-Davidson delivered a small number of military motorcycles based on the 61-cubic-inch Knucklehead engine. Man, that must have been a good gig…being an Army dispatch rider and drawing a Knucklehead for your ride. The military Knuckleheads are rare (no jokes needed here, folks). I can’t remember ever seeing one. But, I found a video of one that was for sale in 2017. Enjoy, my friends…

The XA

The Army preferred the Harley WLA to the Indian 30-50, but it had problems with both motorcycles. In addition to the engine wear and broken headlight problems mentioned above, the rear chain had to be adjusted and replaced frequently on both motorcycles. Engine overheating was another problem (the Harley and the Indian both had V-twin engines, and with a V-twin, the rear cylinder runs hotter than the front cylinder). The rear cylinders could seize because of this.

When the British captured BMW R 12 motorcycles in North Africa and provided a few to the United States, the German machines appeared to provide the answer to the U.S. Army’s major concerns with the WLA. The BMW had a relatively maintenance-free driveshaft to provide power to the rear wheel. The BMW’s horizontally-opposed twin cylinders were both out in the airstream, and as a result the BMW engine ran about a hundred degrees cooler than the Harley and Indian engines. The shaft drive did away with the chain and its wear and adjustment issues. The giant oil bath air cleaner was in a great location. And the BMW had a foot shifter and a hand clutch, a much easier to operate arrangement.

The Army asked both Harley-Davidson and Indian to develop prototypes based on the BMW R 12. Harley-Davidson’s answer was the XA, which looked, for all intents and purposes, as if the BMW engine and shaft drive had been grafted into a standard WLA. In reality, what had happened was very close to that. Harley reverse-engineered the BMW drive train and mated its version into the WLA chassis. The first few, including the prototype, even had the Harley springer front end.

A closeup of the 750cc flathead Harley boxer twin.

Another view of a non-sidecar-equipped Harley XA. Note the twin carbs, the air cleaner location behind the generator, and the foot shift.

The Army was impressed with both the Harley and Indian BMW clones, and they gave both manufacturers production contracts. Harley and Indian each built 1,000 machines based on the BMW design. Harley’s XA was more of a direct copy; Indian’s design had the cylinders tilted up like a modern Moto Guzzi. But while the Harley and Indian development work was under way, the army had been experimenting with other transportation concepts and found that the 4WD Willys (the Jeep) was a much better all-around military vehicle. The Army shifted its resources to Jeep acquisition and did not take delivery on the motorcycles Harley and Indian had already produced. The Army can be fickle like that.

Both Harley and Indian did not pursue BMW clones, since neither company saw any significant civilian demand. Both manufacturers sold their machines to the public and walked away from further development. Today, both the Harley XA and its Indian counterpart are highly collectible.

The Real Knuckleheads?

On that topic of knuckleheads mentioned above…no, not the EL model mentioned several paragraphs up, but the guys running the show in the War Department and over at Indian. You see, the War Department’s spec for their desired military motorcycles called for a 30.5 cubic inch motorcycle (a 500cc twin). Indian snapped to and developed the Model 741 you see in the video below. Harley thought about things for a minute and told the Army they didn’t make a 500cc motorcycle, and they let the Army know they weren’t about to start. Harley further informed the, er, knuckleheads that they made a very good 45 cubic inch motorcycle, and if the Army wanted Harleys, that’s what they could buy.

The knuckleheads (the ones in uniform, not the EL motorcycles) quickly found out that Harley was right. The troops let the brass know that Harleys were better motorcycles, and that’s why the Army ordered many more Harley WLAs than Indians.

There’s one more area in which Harley had to set the knuckleheads straight. During the war, the Army told Harley and Indian to cancel all civilian motorcycle production and make only military motorcycles. Indian saluted and executed. Harley let the War Department know they could go pound sand. By keeping their civilian production going, Harley preserved their customer base. After the war, Harley prospered. Indian? Well, you know how that story ends.

I wrote a story for Motorcycle Classics magazine about the Indian 30-50 (Indian’s World War II workhorse) a few years ago. You can view it here. I also have a video of that bike you might enjoy:

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Shinya Kimura at the Harley Museum

By Joe Berk

Astute readers will remember our post on Shinya Kimura, an artist who works with metal and motorcycles to create motorcycle art. I was both pleased and surprised to see one of his creations at the Harley Museum during our recent Milwaukee content safari.

“Spike,” Mr. Kimura’s custom Knucklehead, was in a Harley museum hall that focused on custom motorcycles, and even before I saw his name, I knew whose work it was.

I believe “Spike” is the very same motorcycle featured in this video:

The Shinya Kimura shop, located in Azusa, California (not far from CSC Motorcycles) is one of the more interesting places I’ve ever visited. I think you would enjoy it, too, although it is not open to the public. I was there on business reasons, and I captured some great photos. If you have a chance, check out our earlier blog.

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The Harley-Davidson Museum

By Joe Berk

I’ve been a motorcycle guy nearly all my life and I’ve owned several motorcycles. Only two of them were Harleys; the first was beautiful but terrible in many ways (a ’79 Electra Glide Classic). The second was beautiful and it was a great machine (a ’92 Heritage Softail). I think Harley’s styling on past models has been awesome. Bottom line? I’m not a Harley fanatic and I’m not a hater. It’s not likely I’d ever buy another Harley, unless I came across a cheap XR-1000 (and that’s probably not in the cards). All that said, I can tell you that the Harley-Davidson Museum is the best motorcycle museum (and maybe the best anything museum) I’ve ever visited (and I’ve visited a lot of them).

First, a bit of logistics about the Museum and our upcoming blogs. We were in Milwaukee specifically to visit the Museum along with a few other Milwaukee highlights. The Harley Museum is too much to take in with just a single visit, and it is definitely too much to cover in a single blog. Our Milwaukee schedule allowed only one Harley Museum visit, but I’ll cover it in three or four blogs. This is the first.

Sticking to the logistics for a moment, the Museum is easy to get to. Plug it into Waze and you’ll drive right up to their front door. There’s plenty of parking, and we snagged a handicap parking spot right at their front door (my handicap tag is the silver lining to a 2009 motorcycle accident). We visited the Museum on a weekday, so it was not too crowded. I’m guessing that’s not the case on the weekends.

Admission is reasonable at $24 per person; for us it was a little less because we qualify for the geezer discount (that knocks it down to $20 per person). Knowing Harley’s customer base, I think a lot of folks get in for $20.

The interior lighting was subdued. Flash photography is allowed, but it’s hard to get decent photos with flash. Nearly everything you see here is with ambient lighting. I had to crank up the Nikon’s ISO, so you may see some graininess in my photos. Mea culpa.

The Museum has three floors, and the building is huge. There are several permanent exhibits and a few special exhibits (ones that change from time to time). The exhibits (both permanent and special) include:

- - Motorcycle Galleries.
  - Mama Tried.
  - Mi Papi.
  - The Engine Room.
  - The Archives.
  - Military Motorcycles.
  - Clubs and Competition.
  - The Tank Wall.
  - Art and Engineering.

Motorcycle Galleries

The Motorcycle Galleries are on the first and second floors, and they dominate the Museum. The Motorcycle Galleries is an appropriate name. The first part is a 180-foot, three-motorcycle-wide display of motorcycles from Harley’s first 50 years, starting with their very first model. The second part features later Harleys.

It was a well assembled exhibit and the motorcycles are beautiful. As I walked the line and took in the motorcycles, I realized I had seen more than a few of these bikes in books. Seeing them in person was special.

Mama Tried

Mama Tried was a custom bike exhibit, containing all sorts of custom Harleys (not the wigged-out choppers you see at the motorcycle shows). I’m not sure what the name (Mama Tried) is supposed to mean, but I thought the exhibit was good. I was liked seeing the Knucklehead customized by Shinya Kimura, whom we’ve written about before.

Mi Papi Has A Motorcycle

You may remember that Joe Gresh wrote an ExNotes review a few years ago about the Spanish language kid’s book, Mi Papi Has A Motorcycle. The book impressed Gresh; apparently, it had the same effect on the Museum staff. There’s an entire hall with large storyboards taken from the book.

The Engine Room

The Engine Room was enlightening. I always found the history and names of Harley engines confusing. VL, UL, flatheads, you know…what do all those designations actually mean? I’m a mechanical engineer and I never could follow it all. The Engine Room made it all clear. We’ll have a future blog on it. This was one of the best parts of the Harley Museum.

The Archives

The Archives were something I’d read about before. An elevator takes you to the third floor. The archives are not open to the public, but you can peer in through a double wire fence. One of Elvis Presley’s motorcycles was near the fence.

Military Motorcycles

The Military Motorcycles exhibit features the Harleys used in World War II and it was the best exhibit of its type I’ve ever seen. This is a topic I’ve been interested in for a l0ng time, going back to before I wrote The Complete Book of Police and Military Motorcycles. There will be a separate blog on this exhibit. It was awesome.

Clubs and Competition

The Clubs and Competition exhibit features a board track with vintage race bikes and projected images of motorcycle racers (and accompanying engine sounds), vintage Harley hill climbers, and Joe Petrali’s land speed record Knucklehead. The Petrali streamliner was awesome.

The Tank Wall

The Tank Wall and the tank exhibits were intriguing. I’ve seen photos of it many times, but to see it in person had more of an impact. To me, the tanks and the engine are what make a Harley. It’s well done. I felt like a kid in a candy store more in this part of the Museum than anywhere else.

Art and Engineering

The Museum has a relatively new Art and Engineering exhibit, which is intended to show how art combines with engineering at Harley-Davidson. I was disappointed, especially because it was one of the main reasons I visited. I felt it was superficial and that it was basically a Harley-Davidson commercial, with almost nothing beyond a very light explanation of how Harley engineering is influenced by art. I get it; they go from sketches to clay mockups to metal, and they select colors along the way. Got it. They use CAD. Got it. Willie G is a wonderful human being, and so was an earlier designer/stylist named Brooks Stevens. Got it. I kind of knew all of that before I got on the airplane to go to Milwaukee (except for the part about Brooks Stevens; that was new to me).

When the motorcycling world discovered Willie G 50 years ago (in the days of the Super Glide, the XLCR Cafe Racer, the Electra Glide Classic, the Low Rider, etc.) there were lots of stories about how Harley went to motorcycle events and studied how riders customized their motorcycles. That was good stuff and those were good creativity inputs, but there was none of that in this exhibit. I was hoping to understand how Harley selected the style and the performance parameters for the new Sportster (a nice-looking motorcycle) and the Pan America (an ugly motorcycle, but all ADV bikes are), and maybe gain some insights into where Harley might go in the future. There was none of that.

I’m probably not a fair judge in this area. I taught engineering for 27 years at Cal Poly Pomona, I’ve had motorcycle engineering assignments related to Harley and other companies, and I wrote a book about engineering creativity. To be fair to Harley, they weren’t targeting retired engineering professors when they created the Art and Engineering exhibit. The exhibit had nice visuals, but for me it was devoid of any meaningful content. That said, we took in nine exhibits at the Harley Museum and only this one didn’t measure up to what I expected. The rest were all outstanding, and 8 out of 9 wins is a pretty good score in anybody’s book.

So there you have it: My Harley-Davidson Museum impressions. Sue and I had a good time. We were there for about three hours, but it would have been easy to spend the entire day. My disappointment in the Art and Engineering exhibit notwithstanding, I strongly recommend that anyone who rides or has even a passing interest in the American icon that is Harley-Davidson visit the Museum. It’s a bucket list destination. I’m glad I went.

At the tail end of our path through the Harley Museum, there’s an area with current model Harleys where you can sit on the bikes and take pictures. A nice guy from the Czech Republic offered to take a picture of Susie and me with my cell phone. It looks good. Our smiles are real.

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