American Motors 232ci 8.27:1 Specs: 3.75 x 3.50 in, 100-135 hp

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American Motors 232ci specs: 232 ci (3.8L) 6-cylinder, 3.75 x 3.50 in (95.3 x 88.9 mm) bore and stroke, 8.27:1 compression. Rated 100-135 hp, 1971–1974.

The American Motors 232ci is oversquare — the 3.75" bore exceeds the 3.5" stroke by 7.1% — a layout that favors airflow and RPM over leverage at the crank. The 3.5" stroke puts mean piston speed at 4,000 ft/min around 6,850 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.75 is long by production standards — less side-load on the cylinder wall and gentler piston acceleration around TDC, the geometry that tolerates high RPM. Each of the 6 cylinders displaces 38.7 ci (634 cc).

8.27:1 is low by modern standards and generally happy on regular pump fuel.

It is one of 5 engines in the American Motors 232ci family, all of them 232 ci — the differences between them are in compression, heads and rating, not displacement. 4 factory variants share these dimensions, rated from 100 to 135 hp across 1971–1974.

Dimensions

Displacement232 ci / 3.8 L
Bore3.75"
Stroke3.5"
Cylinders6
Compression ratio8.27:1
Rod length6.125"
Rod ratio1.75
Bore/stroke ratio1.071
Piston deck clearance0.02"

Construction

Induction1-1
Advertised HP100–135 hp
Years1971–1974

What these numbers mean

Bore/stroke character1.071 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves
Mean piston speed at 6,000 RPM3,500 ft/min — conservative for a street engine
Rod ratio1.75 — long — less side loading on the cylinder wall, favours high RPM
Displacement per cylinder38.7 ci
Static compression8.27:1 — low by modern standards, generally happy on regular pump fuel

Cylinder head

Chamber volume62.5 cc
Rocker ratio1.6:1
Lifter typehydraulic

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Variants sharing these dimensions (4)

These records share identical bore, stroke, displacement and compression. They differ by model year and factory power rating.

YearAdvertised HPCode
1971135 hp—
1972100 hp—
1973100 hp—
1974100 hp—

Factory cars with this engine

Similar engines

← All American Motors 232ci engines