Dealer-accessory Twin-H
1951Approximately 160 hp class
Early dual-carb performance kit
Hudson 308 Twin-H Power enginePhoto: Christopher Ziemnowicz (CZmarlin) · Public domain
Hudson · Hornet 308
Hudson 308 Twin-H Power
The dual-carburetor Hornet package that made Hudson's flathead six a genuine factory performance engine.
308
Cubic inches
Twin-H Power replaced the single-carb intake with dual one-barrels and revised exhaust hardware, giving the Hornet better mixture distribution and a meaningful factory/dealer-backed power increase.
Key variants
All variantsDealer-accessory Twin-HFactory Twin-H 308
Displacement
308 ci
Bore
3.8125"
Stroke
4.5"
Years
1951 dealer kit · 1952–1956 factory availability era
Key Takeaway
Twin-H Power kept the 308's basic flathead architecture but replaced the single-carb intake with two Carter one-barrels on a dual-runner manifold. Better mixture distribution and revised exhaust hardware produced a meaningful factory-backed performance increase.
Technical Specifications
- Compression
- 7.2:1 in documented 1954 Hornet Twin-H specification
- Horsepower
- Approximately 160 hp in early Twin-H descriptions; 170 hp in documented 1953–1954 factory ratings; later Hudson ratings reached about 175 hp
- Torque
- 278 lb-ft @ 2600 rpm in documented 1954 Hornet Twin-H specification
- Architecture
- L-head inline six with dual-carb performance induction
- Block
- Cast iron
- Cylinder heads
- Cast iron/aluminum depending configuration
- Valvetrain
- Side-valve L-head, mechanical lifters
- Aspiration
- Naturally aspirated
- Fuel delivery
- Twin Carter WA-1 one-barrel carburetors on cast-iron intake
- Firing order
- 1-5-3-6-2-4
Twin-H Power kept the 308's basic flathead architecture but replaced the single-carb intake with two Carter one-barrels on a dual-runner manifold. Better mixture distribution and revised exhaust hardware produced a meaningful factory-backed performance increase.
Internal Specifications
Variant-specific values are labeled. Engine families that span multiple years or RPOs can have different heads, cams, induction and rotating parts, so the exact code/year always takes priority.
Identification & Output
- Engine codes / RPO
- Twin-H Power 308 — a factory/dealer performance package on the Hornet 308 rather than a separate displacement code; verify dual Carter WA-1 induction, linkage, head/compression and engine serial
- Casting numbers
- Twin-H identification is package-based rather than proven by one block casting. Verify 308 block dimensions/serial plus dual-carb intake, correct carburetors, air cleaners, linkage and head specification.
- Power rating
- Period brake horsepower / SAE gross-era rating
- Horsepower RPM
- Approximately 160 hp in early Twin-H descriptions; 170 hp in documented 1953–1954 ratings; later ratings approximately 175 hp
- Torque RPM
- 278 lb-ft @ 2600 rpm in documented 1954 Twin-H specification
Operating Specs
- Production notes
- Twin-H used two Carter WA-1 one-barrel carburetors on a cast-iron dual-intake setup. It began as a dealer-accessory package in 1951 and became a factory Hornet option in the early 1950s.
Compatibility Notes
- A visually similar dual-carb setup is not automatically factory-correct Twin-H; verify intake casting, WA-1 carburetor specifications, linkage, air cleaners and application.
- Twin-H can be fitted to related Hudson sixes with adaptation, but carburetor calibration and head/compression must match the engine rather than copying a 308 tune blindly.
Notable Applications
Hudson Hornet Twin-HDealer-installed Hudson Hornet performance packagesHudson Hornet NASCAR/stock-car competition
Strengths
- Factory-backed dual-carb induction
- Better mixture distribution
- Iconic NASCAR-era hardware
Weaknesses / Watch-outs
- Dual-carb synchronization required
- Flathead airflow still limits ultimate rpm
- Original manifolds and carburetors are valuable
Common Upgrades
- Carburetor blueprinting
- Higher-compression head
- 7X-style camshaft and split exhaust
Racing History & Legacy
Twin-H Hornets became the signature Hudson stock-car combination. Hemmings documents 27 wins in 34 NASCAR Grand National events in 1952 and 22 wins in 37 races in 1953, while NASCAR records Hudson-powered champions in 1951, 1952 and 1953.
Twin-H Power made dual carburetors a recognizable Hudson performance trademark and connected showroom Hornets directly with the company’s dominant stock-car image.
References & Image Credit
Engine image: Christopher Ziemnowicz (CZmarlin) · Public domain · source
Hemmings — Twin-H package and output
historical reference
Hemmings — Twin-H NASCAR performance
racing history
1954 Hudson full-line brochure — Twin-H specifications
manufacturer brochure
Hemmings — Hudson Twin-H NASCAR history
racing history
Hudson Motor Car technical service bulletin — 1948–56 six-cylinder engine information
factory service bulletin
1954 Hudson technical data — six-cylinder firing order and ignition specifications
factory technical reference
Hudson Motor Car technical service bulletin — 1948–56 six-cylinder engine information
factory service bulletin
Approved catalog media — Wikimedia Commons
licensed media
Key Factory / Build Variants
Factory Twin-H 308
1952–1956170 hp documented 1953–1954; later about 175 hp
Signature production Hornet performance system
Engineering Notes Worth Knowing
01
308 cu in / 5.0 L with 3.8125 x 4.50-inch bore and stroke.
02
Twin-carb L-head inline-six.
03
Two Carter WA-1 one-barrel carburetors on a cast-iron intake.
04
Factory output reached roughly 160–175 hp depending year; documented 1954 torque was 278 lb-ft.
History · context · related reading
The Story Behind Hudson 308 Twin-H Power
Twin-H Power made Hudson performance visible under the hood. Two carburetors became the signature hardware of the Hornet era and connected showroom cars directly with the company's winning stock-car image.
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