Chevrolet LT7 Specs: 4.057 x 3.385 in, 85 hp

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Chevrolet LT7 specs: 262 ci (4.3L) 6-cylinder, 4.057 x 3.385 in (103 x 86 mm) bore and stroke, 22.8:1 compression. Rated 85 hp, 1982.

The Chevrolet 262ci (LT7) is oversquare — the 4.057" bore exceeds the 3.385" stroke by 19.9% — a layout that favors airflow and RPM over leverage at the crank. The 3.385" stroke does not reach 4,000 ft/min of mean piston speed until about 7,100 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. A rod ratio of 1.739 is in the range most production engines fall in. Each of the 6 cylinders displaces 43.7 ci (716 cc).

At 22.8:1 this is a compression-ignition engine: the ratio is the heat source that lights the fuel, not a knock limit to be managed.

It is one of 17 engines in the Chevrolet 262ci family, all of them 262 ci — the differences between them are in compression, heads and rating, not displacement.

Dimensions

Displacement262 ci / 4.3 L
Bore4.057"
Stroke3.385"
Cylinders6
ConfigurationV6
Compression ratio22.8:1
Rod length5.885"
Rod ratio1.739
Bore/stroke ratio1.199

Construction

Block materialcast iron
Head materialcast iron
ValvetrainOHV
Fuel typediesel
Advertised HP85 hp
Years1982

What these numbers mean

Bore/stroke character1.199 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves
Mean piston speed at 6,000 RPM3,385 ft/min — conservative for a street engine
Rod ratio1.739 — moderate — the range most production V8s fall in
Displacement per cylinder43.7 ci
Static compression22.8:1 — high enough that pump premium or better is normally required

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What cars have the LT7?

6 factory vehicles, 1982–1985. Each year opens that model's engine table.

Similar engines

← All Chevrolet 262ci engines