Valve seat recession / burnt valves
high- Typically appears
- Any mileage if run on unleaded fuel without additive
- Estimated repair
- $800 – $2,500
1928 Cadillac
Series 341Roadster
341 CI V8 · Roadster
The 1928 Cadillac Series 341 Roadster is a pre-war American luxury automobile powered by Cadillac's celebrated 341 cubic-inch (5.6L) L-head V8 — the engine that cemented Cadillac's reputation as an engineering leader in the 1920s. Built on a long, stately ladder frame with open coachwork, it represents the pinnacle of American craftsmanship and style during the late Jazz Age. At nearly 100 years old, this is a full-on antique vehicle, not a daily driver, and it demands the knowledge and patience of a dedicated collector or restorer. These cars were hand-fitted in small numbers and originally bodied by Cadillac or independent coachbuilders. Surviving examples range from museum-quality restorations to honest drivers in varying states of preservation. Expect to find a mix of original and replacement parts — sourcing correct NOS (new-old-stock) or quality reproduction components is the primary ownership challenge. This is not a vehicle for standard shop maintenance intervals. It requires a specialist familiar with pre-war mechanicals: non-hardened valve seats, splash-and-pressure oiling hybrids, mechanical fuel pumps, 6-volt positive-ground electrical systems, and drum brakes on all four corners with mechanical actuation. Plan every season carefully, especially Wisconsin winters.
Reliability
3/5
Verified data
Engine
341 CI (5.6L) L-head V8
Drivetrain
RWD
Fuel
Gasoline
MPG
10 city / 14 hwy / 12 combined
Seats
2
Doors
2
Body
Roadster
MSRP
$3,295
Overview
AI-curatedThe 1928 Cadillac Series 341 Roadster is a pre-war American luxury automobile powered by Cadillac's celebrated 341 cubic-inch (5.6L) L-head V8 — the engine that cemented Cadillac's reputation as an engineering leader in the 1920s. Built on a long, stately ladder frame with open coachwork, it represents the pinnacle of American craftsmanship and style during the late Jazz Age. At nearly 100 years old, this is a full-on antique vehicle, not a daily driver, and it demands the knowledge and patience of a dedicated collector or restorer. These cars were hand-fitted in small numbers and originally bodied by Cadillac or independent coachbuilders. Surviving examples range from museum-quality restorations to honest drivers in varying states of preservation. Expect to find a mix of original and replacement parts — sourcing correct NOS (new-old-stock) or quality reproduction components is the primary ownership challenge. This is not a vehicle for standard shop maintenance intervals. It requires a specialist familiar with pre-war mechanicals: non-hardened valve seats, splash-and-pressure oiling hybrids, mechanical fuel pumps, 6-volt positive-ground electrical systems, and drum brakes on all four corners with mechanical actuation. Plan every season carefully, especially Wisconsin winters.
Known for
- Smooth, torquey 341 CI L-head V8 — a landmark engine for its era
- Exceptional coachbuilt body quality and period luxury appointments
- Long wheelbase and boulevard ride comfort
- Strong collector community and marque club support (Cadillac-LaSalle Club)
Best for
- Dedicated antique car collectors and restorers
- Car show and concours participants
- Drivers who enjoy unhurried, scenic summer touring
- Owners with access to a pre-war specialist mechanic
Watch for
- 6-volt positive-ground electrical system — incompatible with modern accessories without careful conversion
- Non-hardened valve seats require leaded fuel or lead additive for any sustained driving
- Mechanical four-wheel drum brakes demand dramatically longer stopping distances than modern vehicles
- Original rubber components (hoses, seals, gaskets) are 90+ years old and should be assumed failed or failing
- Reproduction and NOS parts supply is limited and expensive; some items require custom fabrication
Common issues by mileage
6 known6-volt electrical system failures (wiring insulation, generator, voltage regulator)
high- Typically appears
- All mileage — age-related
- Estimated repair
- $300 – $1,800
Fuel system deterioration (sediment bowl, carburetor, mechanical fuel pump, cork/rubber seals)
high- Typically appears
- All mileage — age-related
- Estimated repair
- $200 – $1,200
Mechanical brake adjustment and rod/linkage wear
medium- Typically appears
- All mileage — requires frequent adjustment
- Estimated repair
- $150 – $600
Cooling system leaks (hoses, water pump, radiator — all original rubber and gaskets suspect)
high- Typically appears
- All mileage — age-related
- Estimated repair
- $250 – $1,500
Oil leaks from pan gasket, timing cover, and rear main seal (cork and felt seals)
high- Typically appears
- All mileage — normal for era
- Estimated repair
- $200 – $900
Maintenance schedule
- 1 Every fill-up Use leaded fuel substitute or lead additive with every fill-up
The 341 V8 has non-hardened cast-iron valve seats. Unleaded fuel without a lead substitute will cause valve seat recession and burnt valves over time — a costly repair on a pre-war engine.
- 2 Every 250–500 miles of operation Check and adjust engine oil level
Pre-war engines consume and seep oil at rates modern owners find alarming. Consistent level checks prevent oil starvation in a splash-and-pressure hybrid oiling system that has no tolerance for running low.
- 3 Every season or every 1,000 miles, whichever comes first Change engine oil (use a non-detergent or ZDDP-fortified oil appropriate for flat-tappet engines)
Modern detergent oils can dislodge decades of accumulated varnish and sludge, potentially clogging oil passages. Use non-detergent oil or a specialty classic-car oil with high ZDDP content to protect the flat-tappet camshaft.
- 4 Every season before first drive Inspect and adjust mechanical brakes — check rod linkage, clevis pins, and brake shoe adjustment
Mechanical four-wheel brakes require manual adjustment to maintain even, effective stopping. Uneven adjustment causes brake pull, which at pre-war speeds is a serious safety hazard.
- 5 Annually Inspect all rubber hoses, gaskets, and seals
Even 'replaced' rubber components on a car this age harden and crack. A burst hose or blown gasket mid-tour in Wisconsin summer heat can cause rapid overheating and engine damage.
- 6 Annually, before driving season Test and service the 6-volt battery and generator/voltage regulator
6-volt systems have less reserve than 12-volt. A weak battery or out-of-spec voltage regulator can cause generator overcharge, burning out the entire electrical system.
- 7 Before any storage longer than 30 days Drain fuel completely and add fuel stabilizer if storing
Old-design carburetors and fuel bowls are especially vulnerable to ethanol-blend fuel varnishing. Drained and dried systems are far easier to recommission than gummed-up ones.
- 8 Every 500 miles or seasonally Lubricate all grease fittings (chassis, steering, spring shackles)
1928 chassis have many grease zerks that require manual attention. Dry kingpins and shackle bolts wear rapidly and cause dangerous steering slop.
Always defer to the manufacturer's service manual for warranty-mandated intervals.
Cost of ownership
Annual maintenance
$800 – $4,000
Fuel
Expect 10–13 MPG on a good day. Fuel cost is modest given low annual mileage typical of a show/tour car, but premium or ethanol-free fuel plus lead additive every fill-up adds up. Budget $200–$500/year for a typical touring schedule.
Insurance
Agreed-value collector car insurance is strongly recommended and is typically very affordable for a car driven fewer than 2,500 miles/year — often $300–$700/year through specialty insurers. Standard auto insurance is not appropriate for a vehicle of this value and rarity.
Annual costs are low if the car is already properly restored and you're in a maintenance phase. The risk is one major unplanned repair — a full engine rebuild, coachwork repair, or sourcing rare parts — which can run $5,000–$20,000+ depending on scope. Budget accordingly and maintain a restoration fund. This is a passion purchase, not a cost-efficient vehicle.
Seasonal care
Lake Geneva, WI Winter
- Do NOT drive this vehicle on Wisconsin winter roads. Road salt will aggressively attack original or restored metalwork, frame, and underbody in ways that are extremely difficult and expensive to reverse.
- Store in a dry, climate-controlled or at minimum unheated-but-dry garage. Humidity is the enemy of bare metal, chrome, and leather interiors.
- Drain the cooling system completely or use a period-correct non-silicate antifreeze — confirm compatibility with your specific radiator and water pump seals before using modern long-life coolants.
- Remove the 6-volt battery and store it on a trickle maintainer rated for 6-volt systems. Cold kills already-marginal old batteries quickly.
- Drain the fuel tank and carburetor, or fill completely with ethanol-free fuel plus stabilizer to prevent varnish and phase separation.
- Place the car on jack stands to take weight off tires and prevent flat-spotting during multi-month storage.
Summer
- Monitor coolant temperature closely on warm days — pre-war cooling systems have very little thermal headroom in stop-and-go traffic or at idle. Plan routes that avoid long idling.
- Carry extra water and oil on any tour. This is not a car where you assume a gas station will have what you need.
- Check tire pressure before every outing — the narrow bias-ply or bias-belted tires correct for this era are sensitive to heat buildup and run at much lower pressures than modern radials.
- Inspect the canvas or fabric convertible top and its bows seasonally; UV exposure and heat cycles crack aged fabric and stress bows. Store with the top up or under a fitted indoor cover.
- Check that the vacuum-operated windshield wiper (if original) functions — it loses suction under engine load, which is a real visibility issue in summer rain.
- Keep the car out of direct sun for extended periods when possible; original lacquer paint and leather/cloth interior materials are irreplaceable and degrade rapidly under UV exposure.
Comparable vehicles
1928 Packard
Six (526)
Packard's 1928 entry-level six-cylinder line competed directly with Cadillac for upper-crust American buyers. Strong club support, similar parts challenges, and comparable collector market positioning.
No catalog match1928 Lincoln
Model L
Ford's prestige marque fielded a V8 of its own in this era. The Lincoln Model L sits in the same tier of American pre-war luxury collectibles, with comparable rarity and restoration complexity.
No catalog match1928 Chrysler
Series 72
The Chrysler Series 72 offered a powerful inline-six in a similarly styled open body. Slightly more accessible parts supply in some categories, with a strong collector following.
No catalog match1928 LaSalle
Series 303
LaSalle was Cadillac's companion marque, launched in 1927 with a smaller V8. Shares significant mechanical DNA with the 341 Cadillac and is supported by the same Cadillac-LaSalle Club, making it a natural sibling comparison for collectors.
No catalog match