1954 Manhattan Super Power
1954140 hp @ 3900 rpm; 210 lb-ft @ 2000 rpm
Factory McCulloch-supercharged production version
TorqueList Original Technical Art
Kaiser 226 Supercharged Six
Inline6 · Supercharged
Kaiser-Frazer · Supercharged Supersonic Six
Kaiser 226 Supercharged Six
The McCulloch-supercharged 226 that gave the 1954–55 Manhattan 140 horsepower without switching to a V8.
226.2
Cubic inches
With no in-house V8 ready, Kaiser used a McCulloch supercharger to push its old 226 to 140 hp and keep the Manhattan competitive during the horsepower race.
Key variants
All variants1954 Manhattan Super Power1955 Manhattan Super Power
Displacement
226.2 ci
Bore
3.3125"
Stroke
4.375"
Years
1954–1955
Key Takeaway
Kaiser retained the basic 226 flathead six but added a McCulloch VS57 centrifugal supercharger and Carter two-barrel system. Boost let the company raise output substantially without the cost of developing an entirely new engine.
Technical Specifications
- Compression
- Approximately 7.3:1 in 1954 Manhattan specification
- Horsepower
- 140 hp @ 3900 rpm
- Torque
- 210 lb-ft @ 2000 rpm
- Architecture
- Supercharged L-head inline six
- Block
- Cast iron
- Cylinder heads
- Cast iron
- Valvetrain
- Side-valve L-head with solid lifters
- Aspiration
- Centrifugally supercharged
- Fuel delivery
- Carter two-barrel carburetor with McCulloch VS57 centrifugal supercharger
- Firing order
- 1-5-3-6-2-4
- Main bearings
- 4
Kaiser retained the basic 226 flathead six but added a McCulloch VS57 centrifugal supercharger and Carter two-barrel system. Boost let the company raise output substantially without the cost of developing an entirely new engine.
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
- L6-226 / 226 Super Power — factory McCulloch-supercharged Kaiser Manhattan configuration; the blower package did not create a different displacement family
- Casting numbers
- Uses the Kaiser 226 L-head family; 'Kaiser Supersonic' head script is documented on Kaiser-built engines, while the exact block casting should be verified on the individual core rather than inferred from the supercharger package alone.
- Power rating
- Period brake horsepower / SAE gross-era rating
- Horsepower RPM
- 140 hp @ 3900 rpm
- Torque RPM
- 210 lb-ft @ 2000 rpm
Operating Specs
- Production notes
- Standard on 1954–1955 Kaiser Manhattan models; the supercharged version raised the naturally aspirated 226 from roughly 118 hp to 140 hp.
Compatibility Notes
- A factory-supercharged 226 requires blower-specific brackets, drive hardware, carburetion/fuel-system pieces and calibration; a naturally aspirated 226 core alone does not make a correct Super Power assembly.
- Kaiser parts references list a supercharger-specific fuel pump, so restoration should preserve the distinction between supercharged and non-supercharged fuel-system hardware.
Notable Applications
1954 Kaiser Manhattan1955 Kaiser Manhattan
Strengths
- 140 hp from existing 226 architecture
- Strong period torque
- Rare factory-supercharged independent-make history
Weaknesses / Watch-outs
- Supercharger system adds complexity
- Flathead airflow remains limiting
- Rare original hardware
Common Upgrades
- Supercharger rebuild
- Modern ignition
- Careful carburetor calibration
Racing History & Legacy
The supercharged 226 was conceived as a factory performance upgrade rather than a dedicated race engine. Period road tests cited by the VS57 history show roughly a 25% improvement in 0–60 acceleration versus the prior naturally aspirated car and describe the 1954 Manhattan as the second-fastest six-cylinder car available that year.
The 1954–55 Manhattan made Kaiser one of the noteworthy early American adopters of factory centrifugal supercharging, using the McCulloch VS57 to raise the long-serving 226 from roughly 115–118 hp to 140 hp.
References & Image Credit
Hemmings — 1954 Kaiser Manhattan supercharger
historical reference
Hagerty — 1954 Kaiser Manhattan 226/140
vehicle spec
1954 Kaiser Manhattan supercharged 226 specifications
period spec reference
Kaiser Bill — 1951–53/1954–55 Kaiser restoration notes and 226 engine history
specialist restoration reference
Kaiser-Frazer parts cross-reference — 226 and 161 service-part interchange
specialist parts reference
Willys 1954–1960 factory service manual — L6-226 engine and firing order
factory service manual
VS57 — factory-supercharged Kaiser Manhattan history
specialist supercharger history
Key Factory / Build Variants
1955 Manhattan Super Power
1955140 hp class
Final U.S.-production supercharged Kaiser passenger-car version
Engineering Notes Worth Knowing
01
226.2 cu in / 3.7 L with 3.3125 x 4.375-inch bore and stroke.
02
Supercharged L-head inline-six.
03
McCulloch VS57 centrifugal supercharger with Carter two-barrel carburetion.
04
Factory rating: 140 hp and 210 lb-ft.
History · context · related reading
The Story Behind Kaiser 226 Supercharged Six
With no V8 ready during the horsepower race, Kaiser took a different route: supercharge the engine it already had. The result gave the Manhattan a meaningful performance increase and made Kaiser an early adopter of factory centrifugal boost.
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