Pontiac 195ci 10.25:1 Specs: 4.063 x 3.75 in, 120-166 hp

See other engines in this family

Pontiac 195ci specs: 195 ci (3.2L) 4-cylinder, 4.063 x 3.75 in (103.2 x 95.3 mm) bore and stroke, 10.25:1 compression. Rated 120-166 hp, 1961–1963.

The Pontiac 195ci is oversquare — the 4.063" bore exceeds the 3.75" stroke by 8.3% — a layout that favors airflow and RPM over leverage at the crank. The 3.75" stroke puts mean piston speed at 4,000 ft/min around 6,400 RPM, which is where a production bottom end is generally considered at its limit. A rod ratio of 1.767 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 4 cylinders displaces 48.8 ci (799 cc).

10.25:1 is in the range that usually runs on pump premium.

It is one of 2 engines in the Pontiac 195ci family, all of them 195 ci — the differences between them are in compression, heads and rating, not displacement. 9 factory variants share these dimensions, rated from 120 to 166 hp across 1961–1963.

Dimensions

Displacement195 ci / 3.2 L
Bore4.063"
Stroke3.75"
Cylinders4
Compression ratio10.25:1
Rod length6.625"
Rod ratio1.767
Bore/stroke ratio1.083
Piston deck clearance0"

Construction

Induction1-1
Advertised HP120–166 hp
Years1961–1963

What these numbers mean

Bore/stroke character1.083 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves
Mean piston speed at 6,000 RPM3,750 ft/min — in the range typical of performance street engines
Rod ratio1.767 — long — less side loading on the cylinder wall, favours high RPM
Displacement per cylinder48.8 ci
Static compression10.25:1 — in the range that usually runs on pump premium

Cylinder head

Intake valve diameter1.88"
Exhaust valve diameter1.6"
Chamber volume71.3 cc
Rocker ratio1.5:1
Lifter typehydraulic

Run the numbers for this engine

Each link opens the calculator with this engine's specs already filled in.

Variants sharing these dimensions (9)

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

YearAdvertised HPCode
1961120 hp—
1961140 hp—
1961155 hp—
1962120 hp—
1962140 hp—
1962166 hp—
1963120 hp—
1963140 hp—
1963166 hp—

Factory cars with this engine

Similar engines

← All Pontiac 195ci engines