GMC LU2 Specs: 4.00 x 3.48 in, 175 hp

See other engines in this family

The same engine also has a main page: Chevrolet LU2.

GMC LU2 specs: 262 ci (4.3L) 6-cylinder, 4.00 x 3.48 in (101.6 x 88.4 mm) bore and stroke. Rated 175 hp, 1990–1991. Used in the GMC Safari.

The GMC 262ci (LU2) is oversquare — the 4" bore exceeds the 3.48" stroke by 14.9% — a layout that favors airflow and RPM over leverage at the crank. The 3.48" stroke puts mean piston speed at 4,000 ft/min around 6,900 RPM, which is where a production bottom end is generally considered at its limit. Each of the 6 cylinders displaces 43.7 ci (716 cc).

It is one of 4 engines in the GMC 262ci family, all of them 262 ci — the differences between them are in compression, heads and rating, not displacement. 2 factory variants share these dimensions, rated at 175 hp across 1990–1991.

Dimensions

Displacement262 ci / 4.3 L
Bore4"
Stroke3.48"
Cylinders6
ConfigurationV6
Bore/stroke ratio1.149

Construction

Fuel typegas
Firing order1-6-5-4-3-2
Advertised HP175 hp
Years1990–1991

What these numbers mean

Bore/stroke character1.149 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves
Mean piston speed at 6,000 RPM3,480 ft/min — conservative for a street engine
Displacement per cylinder43.7 ci

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Variants sharing these dimensions (2)

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

YearAdvertised HPCode
1990175 hpLU2
1991175 hpLU2

What cars have the LU2?

2 factory vehicles, 1990–1991. Each year opens that model's engine table.

Similar engines

← All GMC 262ci engines