1936-1947 Harley-Davidson EL Export Knucklehead: 61ci OHV Big Twin for the Export Market

The Harley-Davidson EL Export Knucklehead is best understood not as a separate engine design, but as an export-market delivery of Harley-Davidson’s 61 cubic inch EL: the high-compression version of the first overhead-valve Harley Big Twin. Introduced for 1936, the EL sat at the center of one of Milwaukee’s most consequential engineering changes, replacing the visual and mechanical language of the side-valve era with a compact, high-set rocker-box engine that collectors later christened the Knucklehead.

For export customers, the EL carried more than American styling. It represented Harley-Davidson’s attempt to sell a modern, fast, large-capacity OHV motorcycle into markets where British singles and twins, European side-valves, Indian V-twins, and locally taxed displacement classes shaped buying decisions. Surviving export-market ELs are especially interesting because their identity often rests on paperwork, agency history, instruments, lighting, and delivery details rather than an obvious factory badge reading export.

Best Known For: the export-market form of Harley-Davidson’s 61ci EL Knucklehead, the high-compression OHV Big Twin that established the mechanical architecture and collector vocabulary of the pre-Panhead Harley performance era.

Quick Facts

The following table summarizes the EL Export as a collector and restoration subject. It deliberately avoids unsupported production totals or performance claims, because export documentation and surviving-machine histories vary considerably by market.

What matters to a buyer is not simply the word export. The strongest examples are those with credible chain-of-custody evidence: original import papers, foreign registration history, dealer or distributor records, matching period instruments, and engine-number documentation consistent with the claimed year and model.

Why the EL Export Matters

The EL deserves its own discussion because export-market Knuckleheads sit at the intersection of engineering history and documentary history. Mechanically, the EL was Harley-Davidson’s modern OHV Big Twin. Commercially, an export EL shows how that new American performance motorcycle was presented outside the United States, often in markets with different licensing rules, speedometer requirements, lighting regulations, fuel quality, taxation, and dealer support.

Collectors tend to value early OHV Harleys by year, completeness, originality, and documentation. An export-market EL adds another layer: whether the machine can be connected to a genuine overseas delivery rather than being a domestic EL later fitted with a kilometer speedometer or foreign-market accessories. That distinction is not academic. It can affect restoration decisions, judging standards, and the historical narrative attached to the motorcycle.

The Knucklehead also marks a sharp break in Harley-Davidson identity. The exposed pushrod tubes, alloy rocker boxes, dry-sump plumbing, and taller OHV silhouette gave the motorcycle a different presence from the VL and U-series flatheads. It looked faster because it was mechanically more ambitious, and its later role in bob-job and chopper culture made the EL far more than a catalog model.

Historical Context and Development Background

Harley-Davidson’s Position in the Mid-1930s

When the EL appeared in 1936, Harley-Davidson was operating in a difficult environment. The Depression had damaged motorcycle sales, automobiles had become cheaper and more common, and the domestic market leaned heavily on police, commercial, sidecar, and enthusiast customers. Harley’s big twins were respected, but the side-valve VL line was no longer the last word in performance engineering.

Indian remained the principal American rival, especially with the Chief, while British makers were strongly associated with sporting singles and lighter machines in many export territories. Harley-Davidson’s answer was not a lightweight roadster but a large, powerful OHV V-twin that retained Big Twin durability, long-distance stability, and American touring character.

Why Overhead Valves Mattered

The 61ci OHV engine was a major departure from Harley’s established side-valve practice. By placing the valves in the head and operating them through pushrods and rocker arms, the EL could breathe better at higher engine speeds and produce stronger performance from a comparatively compact displacement. The distinctive rocker boxes gave rise to the later collector nickname Knucklehead, because the covers resemble clenched knuckles when viewed from the side.

The first-year 1936 machines have long been treated as a special collecting field because of early production details and the rapid factory development that followed. The OHV system was advanced for Harley-Davidson, but it also brought new sealing, oiling, and heat-management demands. Subsequent refinements helped turn the Knucklehead from a bold new engine into one of the defining American motorcycles of the prewar and immediate postwar period.

Export Conditions and Wartime Disruption

Export-market ELs were sold through agents, distributors, and overseas dealers, but the historical record is less tidy than domestic catalog pages suggest. Some machines were delivered new to foreign civilian buyers; others served police, commercial, or governmental roles. During the Second World War, civilian production and export availability were constrained by military priorities, shipping, material controls, and destination-market conditions.

Harley-Davidson’s wartime reputation was shaped mainly by military machines such as the WLA, not by the EL. Even so, the civilian Knucklehead survived the period and re-emerged strongly in 1946 and 1947, just before the Panhead replaced the Knucklehead for 1948. A documented export EL from those late years is therefore both a postwar civilian motorcycle and one of the last examples of the rocker-box architecture that created the Knucklehead name.

Engine and Drivetrain

The EL engine is a 45-degree air-cooled V-twin with overhead valves operated by pushrods. Its displacement was 61 cubic inches, commonly described in period and modern literature as approximately 1,000 cc. The EL designation identified the higher-compression version of the E-series 61ci OHV Big Twin, though exact compression figures and carburetor details should always be checked against year-specific factory literature and judging references.

Fuel was supplied by a Linkert carburetor on production Knuckleheads, with specific carburetor applications varying by year and specification. Ignition was battery-and-coil based with distributor/circuit-breaker equipment appropriate to the period, and the motorcycle used a 6-volt electrical system. The dry-sump lubrication system was central to the engine’s character and to its restoration demands; oil pump condition, case condition, rocker oiling, and return function are not minor details on a Knucklehead.

Drive passed through a primary chain to a multi-plate clutch and separate four-speed gearbox, with the rider operating a tank-mounted hand shifter and foot clutch in standard period fashion. Final drive was by chain. The whole arrangement makes sense only when judged by 1930s and 1940s expectations: the EL was not merely an engine bolted into a chassis, but a complete hand-shift Big Twin operating system.

Documented Engine and Drivetrain Specifications

This table keeps to the mechanical specifications that are broadly documented for the EL Knucklehead family. Year-by-year details such as carburetor number, generator equipment, and internal running changes should be verified against the exact production year of the motorcycle being evaluated.

Horsepower is often quoted in modern references at roughly 40 hp for the EL, but careful restorers treat period performance figures with caution unless they are tied to a specific year and source. More important in use is the EL’s torque spread and ability to pull road speed without the frantic engine speed expected from smaller contemporary machines.

Chassis, Suspension, and Braking

The EL used Harley-Davidson’s rigid Big Twin chassis format with a leading-link spring fork at the front and no rear suspension beyond the sprung saddle and tire compliance. It was a substantial motorcycle, and that mass worked in its favor on the open roads for which the Big Twin was intended. The chassis gave the EL a planted, long-legged feel rather than the quick steering of a British sporting single.

The visual impression is inseparable from the mechanical layout: long tanks, valanced fenders on many period configurations, exposed pushrod tubes, a low saddle, and the compact but visually prominent OHV top end. Export examples may show market-specific instruments, lighting, horn equipment, or registration hardware, but the underlying stance remains unmistakably that of a late-1930s or 1940s Harley Big Twin.

Chassis and Equipment Reference

The export designation should not be read as a different frame family. The following points identify the standard EL mechanical layout, while acknowledging that destination-market equipment could vary.

The braking system is one of the clearest reminders that the EL belongs to the pre-hydraulic era. A properly set-up machine can be ridden briskly within its period envelope, but the rider must plan stopping distances, use engine braking intelligently, and respect the difference between 1940s drums and later hydraulic or disc systems.

Riding Experience and Mechanical Character

Starting an EL is a ritual, not a button press. Fuel, choke, ignition, throttle position, and kick technique all matter, and a well-sorted Knucklehead rewards a rider who understands the machinery rather than abuses it. The engine comes alive with a hard, uneven Big Twin cadence, sharper and more mechanical than a side-valve U-series, with the rocker boxes adding their own upper-end presence.

The hand-shift and foot-clutch layout changes the rhythm of riding. Low-speed maneuvers demand coordination, especially in traffic or on gradients, and the rider quickly learns to think ahead. Once moving, the EL’s appeal is its broad, muscular delivery rather than high-rev urgency. It pulls with authority from modest engine speeds and gives the sensation of a large flywheel motor working through long mechanical linkages.

Gear changes through the separate four-speed gearbox are deliberate. A good transmission feels positive rather than light, and clutch adjustment makes a large difference to the quality of the ride. The throttle response is period-correct: not instant in the modern sense, but direct enough that a properly carbureted EL feels alive and flexible.

On the road, the rigid rear frame requires respect. Smooth pavement lets the motorcycle settle into a stable, rolling gait; rough surfaces remind the rider that the saddle and tires are doing the rear suspension’s work. The front spring fork is part of the charm and part of the limitation, giving the motorcycle its unmistakable stance while requiring a measured approach to braking and corner entry.

Identification and Originality

What Makes an Export EL an Export EL?

The most important point is that export status is usually a matter of delivery history and market equipment, not a wholly separate EL engine family. A genuine export-market motorcycle may be supported by overseas registration documents, customs papers, distributor or dealer invoices, period photographs, or long-term provenance in a foreign market. Without that evidence, a motorcycle fitted with a kilometer speedometer should not automatically be treated as a factory export machine.

Collectors should inspect the engine number carefully because on Harley-Davidsons of this era the engine number is central to identity and titling. These motorcycles do not use a modern frame VIN system. Frames, cases, and major components should instead be evaluated through year-correct construction details, casting and forging characteristics, belly numbers or case-matching evidence where applicable, and consistency with recognized marque references.

Model-Code Clues and Year-Correct Details

The EL model code identifies the 61ci high-compression OHV Big Twin. The code alone does not prove export delivery. A correct export EL should first be a correct EL for its claimed year, then show credible evidence of export-market delivery or use.

Year correctness is where many otherwise attractive Knuckleheads become complicated. Tanks, fenders, wheels, speedometers, oil pumps, carburetors, generators, horns, lights, saddles, handlebars, and even entire front ends were commonly replaced during decades of use. Postwar riders also modified Knuckleheads into bob-jobs, racers, work bikes, and later choppers, which means originality can be very different from mere old appearance.

Common Swapped and Reproduction Parts

The Knucklehead aftermarket is strong, which is good for keeping motorcycles on the road but challenging for judging originality. Reproduction sheetmetal, tanks, rocker boxes, primary covers, controls, lighting, and trim can be useful in restoration, yet they reduce the evidentiary value of a claimed original export machine if not disclosed. A serious inspection should distinguish between period replacements, modern reproduction parts, and original components that have been refinished.

Paint and badging require the same caution. Factory-correct color, striping, and tank emblem details vary by year, and export machines may have been repainted early in their lives to suit local police, commercial, or agency requirements. The safest approach is to document what is present, compare it to year-specific Harley references, and avoid building a provenance claim around cosmetic details alone.

Model Code and Variant Breakdown

The EL Export is best understood in relation to the surrounding Harley-Davidson Big Twin range. This table separates formal model identity from market description, because export is often a delivery category rather than a separate model code stamped into the engine number.

This distinction matters in the market. A motorcycle advertised as an EL Export should be judged first as an EL, then as an export-delivery machine. If the seller cannot show evidence for the second claim, the motorcycle may still be valuable, but the export description should be treated as unproven.

Performance and Dimensional Specifications

Period and later references commonly associate the EL with approximately 40 horsepower, but output figures should be handled carefully because test methods, factory claims, and year-specific changes are not always presented consistently. The safest documented specification is displacement and architecture: a 61 cubic inch OHV 45-degree V-twin with the Big Twin four-speed driveline.

Top speed claims, quarter-mile times, 0-60 mph figures, and exact curb weights are not consistently documented across export-market ELs in a way that should be repeated as universal data. Equipment, gearing, sidecar fittings, police equipment, tire choice, state of tune, and market-specific accessories all affect real-world performance. In period use, the EL was prized because it was fast and tractable for a large road motorcycle, not because it belonged to a modern stopwatch culture.

Compared With Related Models

EL Export vs Domestic EL

Mechanically, an export-market EL is generally the same core motorcycle as a domestic EL of the same year unless specific market equipment or gearing is documented. The differences a collector should look for are delivery provenance, instrumentation, lighting, registration fittings, and agency history. A domestic EL converted later for overseas use is not the same thing as a documented factory or distributor export delivery.

EL vs E

The EL is the higher-compression member of the 61ci OHV family. The E shares the same basic Knucklehead architecture but was specified for lower-compression use. For collectors, the difference is meaningful because the EL carries the performance identity most closely associated with the early 61ci OHV Harley.

EL vs FL 74ci Knucklehead

The FL brought larger displacement to the Knucklehead line and is often what casual enthusiasts picture when they think of postwar Big Twins. The EL, however, is the original 61ci concept and has particular appeal to collectors who value the first-generation OHV format. A 61ci EL that has been converted with later 74ci parts, or assembled from mixed components, should be described honestly rather than passed off as an untouched EL.

EL vs U-Series Flathead

The U and UL flatheads are wonderful motorcycles in their own right, especially for sidecar and touring use, but they belong to a different engineering philosophy. The EL’s OHV top end gave it a sporting edge and visual identity the side-valves do not have. That is exactly why many buyers cross-shop them: the flathead offers rugged period charm, while the EL represents Harley’s leap into modern overhead-valve Big Twin performance.

EL vs WLA Military 45

The WLA is far more directly tied to wartime service and military collectability. It is also a smaller side-valve motorcycle. An EL Export may have wartime or government-adjacent history in some cases, but it should not be conflated with the WLA’s military production story unless documentation supports that claim.

Restoration and Ownership Notes

Restoring an EL Export correctly is not difficult because information is absent; it is difficult because the motorcycle has often lived several lives. Many Knuckleheads were ridden hard, repaired with whatever parts were available, updated with later Harley components, stripped for bob-job use, or rebuilt cosmetically before modern judging standards became strict. That history can make an honest old machine more interesting, but it complicates claims of factory originality.

Parts availability is better than for many prewar motorcycles, thanks to strong specialist support and a substantial reproduction market. The challenge is selecting parts that match the year, finish, and intended level of restoration. A concours-oriented export EL needs far more than a running Knucklehead engine in a rigid frame; it needs correct small hardware, correct instruments, appropriate electrical equipment, and documentation tying the machine to its claimed identity.

Mechanically, the engine deserves specialist attention. Case condition, oil pump function, rocker-box sealing, valve guides, flywheel assembly, cam chest wear, and cylinder integrity all matter. A Knucklehead can be reliable when built correctly, but it is unforgiving of casual assembly, poor oil control, mismatched cases, incorrect clearances, or worn driveline components hidden beneath polished covers.

Frame and engine number integrity is central. A replacement frame or restamped engine can seriously affect value, legality, and historical credibility. Buyers should involve a marque expert before purchase rather than after discovering that an attractive motorcycle is an assembly of unrelated parts.

Buyer and Restoration Inspection Points

A pre-purchase inspection of an EL Export should be performed with two separate questions in mind: is it a correct EL, and is the export story documented? The following table reflects the areas that tend to decide whether a motorcycle is a serious collector machine or simply an appealing Knucklehead-style rider.

The best inspections are unromantic. A glossy paint job and a famous nickname do not answer the hard questions. A documented, mechanically honest EL with correct major components will always be a stronger motorcycle than a cosmetically perfect machine with uncertain numbers and a vague export story.

Collector and Market Relevance

The EL Knucklehead occupies one of the most desirable territories in Harley-Davidson collecting: early OHV Big Twins with prewar engineering roots and postwar cultural impact. The export-market angle adds scarcity and narrative, but only when supported by evidence. Collectors tend to prize early year-correct components, uncut frames, original cases, correct spring forks, original sheetmetal, period instruments, and clear ownership history.

Exact export production numbers are not consistently documented in a way that should be treated as a single reliable figure. That uncertainty can make genuine examples more intriguing, but it also invites overstatement. A serious seller should be able to separate what is factory fact, what is period evidence, and what is family or dealer lore.

The Knucklehead’s market strength also comes from its afterlife. These motorcycles were prime material for postwar bob-jobs and later choppers because the engine looked magnificent, made useful power, and carried Harley identity in its most concentrated form. That custom history is culturally important, but it means original ELs were consumed by the very enthusiasm that now makes untouched examples valuable.

Cultural Relevance

The EL was not primarily a factory race motorcycle in the way Harley’s smaller competition machines were, and it should not be described as one. Its cultural role was broader: fast road motorcycle, police and agency mount where specified, long-distance touring machine, and later the raw material for American custom culture. In export markets, it also served as an ambassador for a distinctly American idea of performance: large displacement, long wheelbase, deep torque, and mechanical presence.

After the war, surplus skills, mechanical improvisation, and club culture transformed many Big Twins. Fenders were shortened, tanks changed, lights removed, bars swapped, and engines tuned. The Knucklehead became a centerpiece of that movement because it offered both speed and sculpture. Few engines are so visually self-explanatory: rocker boxes, pushrod tubes, cylinders, carburetor, and timing chest all tell the viewer what is happening.

For export-market machines, the cultural story can be even richer. A documented EL that spent its working life in Australia, Britain, Europe, Latin America, South Africa, or another overseas market carries local motorcycling history as well as Milwaukee history. That is why provenance should be preserved rather than erased during restoration.

FAQs

Is the Harley-Davidson EL Export a separate model from the standard EL?

Usually no. The EL Export is best understood as an export-market delivery or specification of the 61ci EL Knucklehead rather than a separate engine family. Export identity is normally supported by destination equipment and documentation such as foreign registration, import papers, distributor records, or period photographs.

What engine does the 1936-1947 Harley-Davidson EL Knucklehead use?

It uses Harley-Davidson’s 61 cubic inch air-cooled 45-degree overhead-valve V-twin. The EL was the high-compression version within the 61ci E-series Knucklehead family. The Knucklehead nickname comes from the distinctive rocker-box shape, not from a factory model name.

How do I identify a genuine EL Export Knucklehead?

First confirm that the motorcycle is a correct EL for its claimed year by examining the engine number, major components, frame, fork, sheetmetal, carburetor, ignition, and year-specific details. Then look for export proof: overseas delivery paperwork, old registration records, distributor history, market-specific instruments, and period photographs. A kilometer speedometer alone is not conclusive.

What is the difference between an EL and an FL Knucklehead?

The EL is the 61ci high-compression Knucklehead. The FL is the larger 74ci Knucklehead introduced during the Knucklehead period. The two share the OHV Big Twin family identity, but displacement and certain year-specific components differ, so mixed EL/FL assemblies should be described accurately.

Are 1936 first-year EL Knuckleheads different from later examples?

Yes, 1936 is a specialist year with early-production details and particular collector interest. The first OHV Big Twins underwent development and refinement after introduction, especially in areas connected with oiling and sealing. Anyone buying or restoring a 1936 EL should consult year-specific references and recognized marque experts.

Are parts available for an EL Knucklehead restoration?

Yes, specialist support and reproduction parts are relatively strong compared with many prewar motorcycles. The difficulty is not simply finding parts, but finding or verifying parts correct for the exact year and claimed specification. Reproduction components can make a rider excellent while reducing originality if represented as factory parts.

What makes an export-market EL more collectible?

Documentation. A true export-market EL with credible overseas delivery history, correct major components, and preserved market equipment has a stronger story than an ordinary EL with later accessories. Collectors value provenance because export production and delivery histories are not always neatly recorded.

Collector Takeaway

The Harley-Davidson EL Export Knucklehead matters because it places the first OHV Harley Big Twin in a global context. The domestic EL was already a major engineering step; an export-market EL shows how that step reached riders and agencies outside the United States, where the motorcycle had to prove itself against very different roads, taxes, fuel, regulations, and expectations.

For collectors, the best EL Export is not the shiniest one. It is the motorcycle whose mechanical identity, year-correct parts, engine-number integrity, and export provenance all agree. When those elements align, the machine becomes something unusually satisfying: a 61ci Knucklehead with the right engineering, the right silhouette, and a documented life beyond Milwaukee’s home market.