Ethanol fuel degradation of carburetor and fuel lines
high- Typically appears
- Any mileage / any age on original or older-rebuild fuel system
- Estimated repair
- $400 – $1,800
1929 Cadillac
Series 341Roadster
341 CI V8 · Roadster
The 1929 Cadillac Series 341 Roadster is a pre-Depression-era American luxury automobile powered by Cadillac's legendary 341 cubic-inch flathead V8 — the engine that established Cadillac as the "Standard of the World" through the late 1920s. Built on a long 140-inch wheelbase, these open-body roadsters were coachbuilt expressions of wealth and engineering ambition, featuring a 3-speed sliding-gear transmission, mechanical four-wheel brakes, and striking torpedo-style coachwork. Nearly every surviving example has been restored at least once in its 95-plus year life. This is a collector and show vehicle first, a driver second. Parts availability depends heavily on specialty suppliers, marque clubs (Cadillac-LaSalle Club), and the used-parts network — not your local parts store. Mechanical simplicity works in the owner's favor: no electronics, no fuel injection, no sensors. What breaks is usually cast iron, rubber, or fabric, and a skilled old-iron mechanic can address most of it. Owning a 1929 Series 341 Roadster in Lake Geneva, Wisconsin means storing it properly through long winters. Salt air, freeze-thaw cycles, and moisture are the enemies of the open bodywork, canvas top, and uncoated cast-iron components. Expect to invest as much in storage and cosmetics as in mechanical upkeep.
Reliability
3/5
Verified data
Engine
341 CI Flathead V8
Drivetrain
RWD
Fuel
Gasoline
MPG
8 city / 13 hwy / 10 combined
Seats
2
Doors
2
Body
Roadster
MSRP
$3,295
Overview
AI-curatedThe 1929 Cadillac Series 341 Roadster is a pre-Depression-era American luxury automobile powered by Cadillac's legendary 341 cubic-inch flathead V8 — the engine that established Cadillac as the "Standard of the World" through the late 1920s. Built on a long 140-inch wheelbase, these open-body roadsters were coachbuilt expressions of wealth and engineering ambition, featuring a 3-speed sliding-gear transmission, mechanical four-wheel brakes, and striking torpedo-style coachwork. Nearly every surviving example has been restored at least once in its 95-plus year life. This is a collector and show vehicle first, a driver second. Parts availability depends heavily on specialty suppliers, marque clubs (Cadillac-LaSalle Club), and the used-parts network — not your local parts store. Mechanical simplicity works in the owner's favor: no electronics, no fuel injection, no sensors. What breaks is usually cast iron, rubber, or fabric, and a skilled old-iron mechanic can address most of it. Owning a 1929 Series 341 Roadster in Lake Geneva, Wisconsin means storing it properly through long winters. Salt air, freeze-thaw cycles, and moisture are the enemies of the open bodywork, canvas top, and uncoated cast-iron components. Expect to invest as much in storage and cosmetics as in mechanical upkeep.
Known for
- Smooth, torquey 341 ci flathead V8 — refined for the era
- Prestige coachbuilt open bodywork from Fisher or independent coachbuilders
- Long-wheelbase ride comfort uncommon among 1920s cars
- Cadillac's industry-leading fit and finish standards for 1929
Best for
- Concours d'Elegance and car show enthusiasts
- Cadillac-LaSalle Club members and marque collectors
- Experienced antique-car owners comfortable with pre-war mechanicals
- Seasonal fair-weather drivers who can provide proper enclosed storage
Watch for
- Reproduction and NOS parts are expensive and sometimes unavailable
- Canvas or fabric top condition — restoration runs $3,000–$8,000+
- Ethanol in modern pump gas attacks original fuel-system materials
- Brake system is mechanical (not hydraulic) — requires precise adjustment and skilled knowledge
- Open roadster body is highly vulnerable to moisture, rust, and UV damage
Common issues by mileage
6 knownMechanical brake adjustment and lining wear
high- Typically appears
- Any — requires periodic expert adjustment
- Estimated repair
- $300 – $1,200
Rubber seal, gasket, and hose deterioration
high- Typically appears
- Any — rubber degrades with age regardless of use
- Estimated repair
- $200 – $1,500
Cooling system failure (cracked hoses, weak water pump, clogged radiator)
medium- Typically appears
- Any — cast-iron block traps scale buildup over decades
- Estimated repair
- $400 – $2,500
Electrical system faults (6-volt positive-ground wiring, corroded connections)
medium- Typically appears
- Any — 6V systems are sensitive to voltage drop from corroded grounds
- Estimated repair
- $150 – $1,000
Body and frame rust, canvas top deterioration
medium- Typically appears
- Any — especially cars stored in humid or un-climate-controlled environments
- Estimated repair
- $1,500 – $15,000
Maintenance schedule
- 1 Every fill-up and before any storage period Run ethanol-free premium fuel or treat with ethanol-compatible fuel stabilizer
E10/E15 pump gas corrodes original zinc carb parts, attacks rubber fuel lines, and absorbs water during storage. Ethanol-free fuel (often available at marinas near Lake Geneva) is strongly preferred.
- 2 Every season or after any 500 miles of driving Mechanical brake inspection and adjustment
The 1929 Series 341 uses mechanical (rod-and-cable) four-wheel brakes. They require precise, knowledgeable adjustment to perform safely — not a job for someone unfamiliar with pre-hydraulic systems.
- 3 Every season or every 1,000 miles Engine oil and filter service using non-detergent straight-weight oil
Modern detergent oils can dislodge decades of accumulated deposits in old engines, causing sudden seal leaks. Use non-detergent SAE 30 or a period-correct viscosity unless the engine has been freshly rebuilt with modern seals.
- 4 Every 2 years Cooling system flush and inspection
Cast-iron block and head accumulate scale. Period-correct coolant (low-silicate or plain water with rust inhibitor) is appropriate. Check for cracked hoses and weeping water pump.
- 5 Every season or every 500 miles Lubricate all chassis grease fittings (zerks)
The 1929 chassis has numerous grease points on kingpins, tie rods, and spring shackles. Neglecting these leads to rapid wear on irreplaceable parts.
- 6 Every season Inspect and treat canvas top and convertible fabric
UV exposure and moisture cause canvas to crack, shrink, and mildew. Clean and treat before summer use; store with top properly supported to prevent stress creases.
- 7 Every spring before first start 6-volt battery load test and terminal cleaning
6V systems have very little margin for voltage drop. Corroded terminals or a weak battery will prevent starting and can burn out the generator or coil.
- 8 Every fall before winter storage Full pre-storage inspection: drain float bowls, fog cylinders, stabilize fuel
Long Wisconsin winters mean 5–6 months of storage. Varnish in carb float bowls, dry cylinder walls, and stale fuel are the top causes of spring no-starts and internal damage.
Always defer to the manufacturer's service manual for warranty-mandated intervals.
Cost of ownership
Annual maintenance
$800 – $5,000
Fuel
Ethanol-free premium is strongly recommended; expect 8–12 MPG. At 1,000–2,000 miles/year of typical show-car use, fuel cost is modest — but ethanol-free fuel commands a premium price per gallon.
Insurance
Agreed-value collector car insurance is standard for this vehicle. Annual premiums vary widely by stated value and usage, but agreed-value policies on a show-quality example are often $400–$1,200/year through specialty insurers.
Annual maintenance costs are highly variable and restoration-phase-dependent. A freshly restored, well-sorted car in annual show use might see $800–$1,500/year in routine upkeep. A car needing cosmetic or mechanical restoration work can easily run $5,000–$20,000+ in a single season. Budget separately for proper enclosed winter storage — unheated but dry is the minimum; climate-controlled is ideal in Wisconsin. Parts sourcing through the Cadillac-LaSalle Club and specialty antique suppliers is essential.
Seasonal care
Lake Geneva, WI Winter
- Store in an enclosed, dry space — unheated is acceptable if dry; avoid dirt floors that wick moisture. Climate-controlled is ideal for a car of this value.
- Drain carburetor float bowls completely before storage to prevent varnish buildup from ethanol-blended fuel.
- Add ethanol-free fuel stabilizer to a full tank to prevent moisture absorption and gum deposits.
- Fog cylinders with a light oil through the spark plug holes to prevent corrosion on cylinder walls during long storage.
- Remove or connect a trickle charger to the 6-volt battery — cold kills 6V batteries faster than 12V systems.
- Place vehicle on jack stands or flat wood blocks to relieve tire flat-spotting during 5–6 months of Wisconsin storage.
Summer
- Inspect cooling system thoroughly before summer show season — the flathead V8 runs warm and has no overflow recovery system.
- Check tire condition carefully; antique bias-ply or reproduction tires age-crack regardless of tread depth. Heat accelerates this.
- Inspect canvas top for UV damage and treat with appropriate fabric protectant before extended sun exposure.
- Keep a fire extinguisher in the car — older fuel systems (rubber lines, non-hardened seats) can develop leaks that drip onto hot exhaust.
- Monitor engine temperature closely in stop-and-go show traffic; lack of electric fans and thin coolant passages make overheating a real risk.
Comparable vehicles
1929 Packard
Model 626
Direct luxury competitor to Cadillac in 1929 — similar price tier, straight-eight engine, comparable open-body coachwork. Strong club support and parts network through the Packard Club.
No catalog match1929 Lincoln
Model L
Ford Motor Company's flagship luxury marque for 1929, powered by a large V8. Same collector tier, similar restoration economics, and a dedicated owners club.
No catalog match1929 LaSalle
Series 328
Cadillac's companion marque for 1929 — same GM platform, similar V8, lower original price point. Shares much of the Cadillac-LaSalle Club support network and some parts commonality.
No catalog match1930 Cadillac
Series 353
The direct evolution of the 341 — slightly larger displacement, refined mechanicals, same basic architecture. A 353 competes in the same collector market and can share some parts with the 341.
No catalog matchIf you're shopping for one
Red flags
- No restoration documentation or provenance — could hide structural repairs, incorrect parts, or flood/fire history
- Mismatched body panels, incorrect paint colors, or non-period accessories suggesting a compromised restoration
- Evidence of leaking fuel near the carburetor or on the intake manifold — fire hazard on a car with no modern safety systems
- Soft, spongy, or uneven brake response during any test drive — mechanical brakes require expert adjustment to be safe
- Any rust bubbling under paint on the lower body, running boards, or fenders — open cars trap water in body seams
- Non-original engine, transmission, or rear axle without full disclosure — dramatically affects collector value
What to inspect
- Frame rails and cross-members for rust perforation — look underneath, not just at the surface
- Body sills and floor structure under the carpet or mat for hidden rot
- Engine for correct casting numbers matching 1929 production (not a later replacement block)
- Completeness and originality of all brightwork, lamps, hood ornament, and instrument cluster
- Condition and operation of all four mechanical brakes — test adjustment before any test drive
- Canvas top frame for broken bows, torn fabric, and leaking seams
- Fuel system integrity — smell for fuel leaks around carburetor and braided lines
- Documentation: restoration receipts, marque club judging sheets, ownership history