1929–1930 Dodge Brothers DA Six Roadster: 112-Inch Wheelbase

Dodge Brothers offered the DA Six during the 1929 and 1930 model-year period, and the roadster combined a 112-inch-wheelbase chassis with a 208-cubic-inch L-head inline-six. Factory specifications commonly rated that engine at 63 horsepower at 3,000 rpm, delivered through a three-speed manual gearbox and rear-wheel drive.

The DA arrived soon after Chrysler acquired Dodge Brothers in 1928, but it retained the Dodge Brothers name, the marque's reputation for sturdy construction, and four-wheel hydraulic brakes. The roadster was the light, open member of a broad DA body catalog that also included closed coupes and sedans.

Best known for bringing six-cylinder power and hydraulic braking to a compact Dodge chassis, the DA roadster now attracts collectors who want a usable prewar open car without the scale, complexity, or purchase pressure associated with the era's senior models.

Its appeal is also visual. The long hood, compact passenger compartment, exposed running boards, upright radiator shell, separate headlamps, and abbreviated rear deck give the roadster cleaner proportions than the more practical DA sedans. Correctly restored examples have a light, purposeful stance that is easily lost when fitted with incorrect wheels, oversized tires, modern upholstery, or excessive accessories.

Quick Facts

The following table summarizes the specifications that define the DA Six roadster and separate it from adjacent Dodge Brothers series. Model-year descriptions can differ among references because production dates, sales dates, and registration years were not always recorded in the same way.

The DA designation matters because it identifies the chassis and mechanical family, not merely a styling package. Registration paperwork that says only “Dodge,” “Six,” or “Roadster” is not enough to establish that a surviving car began life as a genuine DA roadster.

Why the DA Six Roadster Matters

The DA put a six-cylinder engine into a 112-inch-wheelbase Dodge at a time when buyers increasingly expected smoother power than a four-cylinder car could provide. Its 63-horsepower rating was modest by later standards, but it was appropriate for contemporary roads, fuel, tires, and braking distances.

The four-wheel hydraulic brake system is central to the car's historical value. Many inexpensive cars of the late 1920s still relied on mechanically operated brakes, while Dodge had already committed to hydraulics. That system gave the DA a practical advantage when properly maintained, although age, moisture, deteriorated hoses, and corroded cylinders can erase it completely.

The roadster also records a rapidly disappearing body form. It offered minimal weather protection, a folding top, side curtains rather than wind-up side glass, and little enclosed luggage space. Buyers soon moved decisively toward closed cars, making authentic open DA bodies much less common among survivors than four-door sedans.

Historical Context and Development

Dodge Brothers After the Chrysler Acquisition

Chrysler Corporation purchased Dodge Brothers in 1928 from Dillon, Read & Company. The acquisition gave Chrysler a large manufacturing base, an established dealer network, and a marque known for conservative, durable automobiles. The DA was sold during the first phase of Chrysler control, before the Dodge identity and component system became more deeply integrated into Chrysler's corporate engineering structure.

The timing was difficult. The DA entered the market as American manufacturers expanded six-cylinder offerings, then encountered the economic contraction that followed the October 1929 stock-market crash. Chevrolet promoted high-volume six-cylinder motoring, while Plymouth competed below Dodge and Chrysler served buyers seeking greater size or equipment. Buick, Nash, Studebaker, Pontiac, and other makes further crowded the six-cylinder field.

Design Priorities

Dodge emphasized a useful combination of smoothness, structural strength, hydraulic brakes, and familiar controls rather than sporting specification. The roadster shared its basic chassis and powertrain with heavier DA bodies, so its lower body mass gave it the liveliest response in the family without requiring a different engine tune.

Styling followed late-1920s American practice. The radiator stood nearly vertical, the hood was visually separated from the cowl, and the fenders remained distinct from the body. Steel exterior panels depended on a substantial internal framework, including wood in the body structure, a construction method that has major consequences for restoration.

The DA was not a homologation model and had no factory competition program comparable with later performance Dodges. Its historical case rests on production-car engineering and body-style rarity, not a manufactured racing pedigree.

Engine and Drivetrain

Side-Valve Six-Cylinder Construction

The DA engine is a water-cooled inline-six with its valves mounted in the block beside the cylinders, the layout usually called an L-head or flathead. A single camshaft operates the valves through tappets, while the detachable cylinder head contains no rocker arms or overhead valve gear. The architecture kept height and manufacturing cost under control, though it imposed a less direct combustion path than an overhead-valve design.

Displacement is commonly listed as 208 cubic inches, with a 3.25-inch bore and 4.1875-inch stroke. The long stroke favored low-speed pulling ability rather than high engine speed. Factory output is generally given as 63 horsepower at 3,000 rpm, a figure that should not be confused with modern net horsepower measurement.

A single updraft carburetor supplies the mixture through a relatively simple intake system. Spark comes from a distributor and coil, while a conventional liquid-cooling system circulates coolant through the block, head, radiator, and water pump. Correct ignition timing, unobstructed water passages, and a clean radiator are more important to satisfactory road behavior than attempts to extract additional power.

Lubrication practices and internal bearing work require particular care during rebuilding. Before ordering parts, a rebuilder should identify the exact engine and inspect the crankshaft, bearing construction, oil passages, and previous machining. Assumptions based on later Chrysler flathead sixes can lead to incorrect components or clearances.

Clutch, Gearbox, and Rear Axle

A dry single-plate clutch feeds a three-speed manual gearbox. The transmission predates the fully synchronized gearboxes familiar to modern drivers, so clean shifts depend on deliberate timing and, when changing down, double-declutching. A propeller shaft carries power to a live rear axle.

This table records the principal powertrain specifications consistently associated with the DA. Torque and governed engine-speed figures are omitted because dependable factory values are not consistently reproduced in surviving references.

The headline horsepower figure tells only part of the story. The long-stroke engine delivers its useful effort at low speed, while the low gearing lets the car pull away without excessive clutch slip. Sustained high-speed running is neither the engine's design brief nor a sensible test of a nearly century-old cooling and lubrication system.

Chassis, Suspension, and Braking

The DA uses a separate steel frame with the body mounted above it. A rigid beam axle locates the front wheels, and a live axle serves at the rear, with semi-elliptic leaf springs providing suspension. The layout is simple, strong, and serviceable, but worn shackles, spring pins, steering joints, or loose body mountings can make an otherwise sound car feel imprecise.

Four-wheel internal-expanding hydraulic drum brakes distinguish the DA from cars still using rods and cables. The system needs correct wheel-cylinder operation, sound hydraulic lines and hoses, properly arced linings, round drums, and careful adjustment. A DA with neglected hydraulics can pull sharply or provide little useful pedal despite appearing complete.

Period wheel equipment included steel wheels appropriate to the DA's tire size and hub pattern, with equipment differing by catalog specification and market. Wire-wheel conversions, later hydraulic components, and wheels from related Chrysler products appear on restored cars, so physical fit should never be treated as proof of factory correctness.

The concise chassis table below identifies the architecture a restorer should expect to find. It avoids dimensions and component-brand claims that can change with body style, production date, or replacement history.

The 112-inch wheelbase is short enough to keep the roadster manageable, but its behavior depends heavily on spring condition and frame alignment. Reversing decades of improvised repairs often transforms steering accuracy more effectively than fitting non-original modern components.

Driving Experience and Handling Dynamics

A correctly sorted DA starts with a measured six-cylinder pulse and settles into a slow idle. Throttle response is progressive rather than immediate, and the engine works best when the driver uses its low-speed torque instead of stretching each gear. An updraft carburetor that is worn, incorrectly jetted, or drawing air through a leaking manifold can turn that easy delivery into hesitation and flat spots.

The gearbox asks for patience. First gear gets the car moving, second handles much of the work in town, and top gear suits open roads once the engine has gathered speed. Gear whine is not unusual in an early transmission, but heavy knocking, jumping out of gear, or a clutch that drags should not be dismissed as period character.

Steering is heavy while parking and becomes more communicative once moving. The beam axle follows cambers and broken surfaces more noticeably than an independent front suspension, while the narrow tires and tall body allow visible roll. The roadster's lighter open body makes it feel more responsive than a DA sedan, although chassis flex and body shake increase sharply if the timber structure or mounting points have deteriorated.

Properly rebuilt hydraulic brakes provide a firm, progressive pedal by late-1920s standards. They still demand anticipation because tire contact area, drum cooling, and available friction are limited. A long or sinking pedal signals a defect, not an authentic driving trait.

Identification and Originality

Serial Numbers, Engine Numbers, and the DA Code

The DA predates the standardized 17-character VIN by several decades. It was identified through factory serial and engine numbers, and registration authorities sometimes transferred one number or the other onto later titles. A buyer should compare every visible stamping and plate with the title, period parts books, factory serial listings, and recognized Dodge Brothers club references.

The presence of a DA engine does not prove roadster identity because engines and major chassis parts were shared across body styles. Likewise, an open body mounted on a genuine DA frame may be a later conversion. The serial sequence, frame dimensions, body construction, mounting details, hardware, and documented ownership history must agree.

Engine-number and serial-number consistency is a more useful standard than the modern phrase “matching numbers.” Early manufacturers did not necessarily stamp all major components with one repeated identity number. An unstamped replacement engine or a unit from another DA may be mechanically correct yet reduce historical originality.

Body Details and Correct Equipment

An authentic roadster should show construction and hardware consistent with a factory open body, including the cowl, door openings, top mounting arrangement, windshield, rear deck, seat structure, and body-to-frame attachment points. Welded-over sedan pillars, fabricated door tops, modern square tubing, and irregular subrails are warning signs of a conversion or heavily reconstructed body.

Surviving examples often carry later carburetors, generators, distributors, lamps, wheels, gauges, steering wheels, and hydraulic cylinders. These substitutions may improve serviceability, but they should be disclosed and priced accordingly. A component that looks “old” is not necessarily DA-correct.

Factory colors were sold as coordinated body, molding, wheel, and stripe combinations rather than through the modern retail paint-code system familiar to postwar collectors. Restoration decisions should rely on factory literature, protected paint found during disassembly, period photographs, and documented unrestored cars. Bright metallic finishes, vinyl upholstery, incorrect wood-grain treatment, and modern carpet can make an expensive restoration historically unconvincing.

DA Six Variant and Body-Style Breakdown

The DA was a model family rather than a roadster-only series. Exact catalog wording and availability could differ by model year and market, but these are the principal configurations a researcher is likely to encounter.

There was no factory DA roadster homologation special or recognized competition derivative. Claims of a “racing” DA require period documentation tied to that individual car, not accessories added during a later restoration.

Performance and Dimensional Specifications

Standardized acceleration and top-speed tests were not published for the DA roadster with the consistency expected of postwar road tests. Body weight, axle ratio, tire size, engine condition, and testing method could materially alter results, so unsupported estimates are best excluded.

No single verifiable roadster curb-weight, 0–60 mph, quarter-mile, or maximum-speed result is used here. Period listings may quote shipping weight rather than a fueled road-ready figure, and modern estimates are often repeated without an identifiable factory bulletin or instrumented test.

Compared With Related Dodge Brothers Models

Victory Six

The Victory Six preceded the DA and used a different chassis identity and body architecture. Superficially similar restored cars can be confused when radiator shells, lamps, wheels, or bodies have been exchanged, but a Victory Six should not be represented as a DA merely because it carries a Dodge six-cylinder engine.

Dodge Senior Six

The Senior Six was the larger and more expensive Dodge offering, with greater displacement and a longer chassis than the DA. Its additional size suited heavier closed bodies and buyers seeking more formal accommodation. Senior Six powertrain, axle, wheel, and trim parts should not be assumed interchangeable with DA components.

1930s Dodge Sixes

Subsequent Dodge series adopted revised chassis, body styling, and increasingly integrated Chrysler Corporation engineering. Later flathead-six engines are often easier to locate and may be installed in early cars, but shared architecture does not make them date-correct DA engines. Engine numbers, castings, mountings, accessories, and physical dimensions need comparison before a car is described as original.

Ownership and Restoration Notes

A DA roadster is mechanically straightforward, but a complete restoration is rarely simple. Engine work can require specialist machining, bearing expertise, valve-seat repair, crack inspection, and careful cleaning of oil and cooling passages. Carburetor and distributor rebuilding should preserve the original housings where practical rather than replacing every visible component with a modern substitute.

Cooling problems frequently result from sediment in the block, blocked radiator tubes, a worn pump, incorrect ignition timing, or a lean mixture. Replacing the radiator without cleaning the engine may provide only temporary relief. The fuel tank and lines also deserve inspection because rust and aged sealants can repeatedly contaminate an otherwise rebuilt carburetor.

The hydraulic brakes need complete assessment, not a fluid top-up. Wheel and master cylinders can corrode internally, flexible hoses can collapse, and drums may be worn beyond a useful diameter. Correct lining material and shoe fit matter because these cars generate limited hydraulic pressure compared with a power-assisted modern system.

Body restoration usually consumes more time than drivetrain work. The roadster's doors, cowl, rear quarters, and top geometry depend on sound framing. New wood must be fitted with the body correctly braced and the frame checked for alignment, otherwise door gaps and top fit can change after final assembly.

Routine service includes frequent chassis lubrication, engine-oil checks and changes appropriate to use, ignition-point adjustment, coolant inspection, brake-fluid monitoring, and attention to wheel bearings and steering joints. Original manuals specify service far more frequently than modern owners may expect.

Mechanical service parts can often be sourced through vintage specialists, club networks, and rebuilders, but DA-specific sheet metal, roadster hardware, instruments, and trim are scarce. Reproduction availability is selective. Buying a dismantled project without windshield hardware, top irons, gauges, handles, or roadster-only body fittings can turn an apparently inexpensive car into a long search for parts.

Buyer and Inspection Points

A serious inspection should determine whether the car is a sound DA roadster before evaluating paint quality or accessory count. These checks focus on expensive faults and the areas most likely to reveal an incorrect or incomplete restoration.

A cosmetically aged but complete and structurally honest car is often a stronger basis than a freshly painted example with uncertain identity. Paint can hide modern welds, filler, damaged wood, and body conversions, while missing DA-specific hardware may exceed the cost of correcting visible cosmetic wear.

Collector and Market Relevance

Open cars generally draw stronger collector attention than closed sedans from the same late-1920s series, partly because roadsters survived in smaller numbers and provide a more direct driving experience. The DA adds a usable six-cylinder engine and hydraulic brakes, two features that make touring less demanding than in many lower-priced contemporaries.

Collectors place the greatest value on documented factory roadsters retaining their correct chassis type, period-consistent engine, original body structure, roadster hardware, instruments, lamps, wheels, and trim. An older restoration with authentic materials can be more desirable than a glossy rebuild finished with incorrect upholstery, modern fasteners, or assembled accessories from several Dodge series.

Exact DA roadster production totals are not consistently documented in readily available model references, and survival figures are still less certain. Rarity claims should therefore be supported by factory records, marque-club research, or a traceable registry rather than auction language.

Auction interest tends to reward completeness and open-body authenticity. Modified drivetrains, converted bodies, and unresolved title numbers narrow the pool of knowledgeable buyers, even when the car presents well in photographs.

Cultural Relevance and Club Support

The DA belongs to the period when an open roadster was changing from ordinary transportation into a less practical choice. Closed steel-bodied cars were becoming more affordable, quieter, and better protected from weather, so the roadster's visual appeal could no longer offset its limitations for most buyers.

No major factory racing campaign defines the DA Six roadster. Its modern cultural presence comes chiefly through antique-car touring, concours events, regional shows, and preservation groups such as Dodge Brothers and broader prewar automobile clubs. These networks are valuable because surviving parts books, service bulletins, photographs, and unrestored reference cars often answer questions that general repair manuals cannot.

Period owners and later hobbyists fitted heaters, auxiliary lamps, horns, wire wheels, replacement carburetors, and higher-compression or later engines. Such modifications form part of individual-car history, but they should not be presented as factory DA roadster equipment without documentation.

Frequently Asked Questions

What engine is in the 1929–1930 Dodge Brothers DA Six Roadster?

It uses a naturally aspirated 208-cubic-inch L-head inline-six, commonly rated at 63 horsepower at 3,000 rpm. It has side valves, a single updraft carburetor, distributor ignition, and liquid cooling.

What does the DA code mean on an early Dodge?

DA identifies the Dodge Brothers model series and its associated chassis family. It should be confirmed through the car's serial information, dimensions, mechanical specification, body construction, and period documentation rather than badges alone.

Does a Dodge DA have a modern VIN?

No. The DA predates the standardized 17-character VIN. It was identified through factory serial and engine numbers, and either number may appear on an old title depending on the jurisdiction and registration history.

How can a buyer tell whether a DA roadster is genuine?

Inspect the cowl, door openings, subrails, windshield mounts, top attachments, rear deck, body mounts, and internal woodwork for factory-style open-body construction. Then compare serial and engine information with recognized DA records and look for documentary history. A genuine DA chassis under a converted sedan body is not an original DA roadster.

Did the DA Six Roadster have hydraulic brakes?

Yes. The DA used four-wheel hydraulic internal-expanding drum brakes. Their effectiveness depends on cylinder condition, sound hoses and lines, round drums, correct linings, and proper adjustment.

What are the most expensive DA roadster restoration problems?

Rotten body wood, an incomplete or converted roadster body, a cracked or heavily worn engine, damaged brake drums, missing top and windshield hardware, and unresolved serial-number paperwork can dominate restoration cost. DA-specific trim and open-body fittings are generally harder to replace than normal service parts.

Are parts available for a Dodge Brothers DA Six?

Routine ignition, fuel, brake, bearing, gasket, and engine-rebuilding needs can often be handled through vintage specialists and club networks. Correct sheet metal, gauges, lamps, wheels, roadster top hardware, windshield pieces, and trim are much less plentiful, making completeness especially valuable.

Collector Takeaway

The DA Six roadster deserves attention for three concrete reasons: its 208-cubic-inch six gives it useful low-speed flexibility, its four-wheel hydraulic brakes were advanced for its price era, and its open body survived in far smaller numbers than the sedans that carried the same chassis. Those facts make it both a credible touring car and a demanding restoration subject.

The best example is not necessarily the one with the deepest paint. It is the car whose DA identity, roadster body, serial history, frame, engine specification, timber structure, and scarce open-body fittings agree. Preserve those elements, rebuild the brakes and cooling system without shortcuts, and the result explains late-1920s Dodge engineering far more clearly than any over-restored showpiece assembled from convenient substitutes.