Dodge LA 318 2-bbl, Electronic Lean Burn Specs: 3.909 x 3.311 in, 145 hp

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Dodge LA 318 2-bbl, Electronic Lean Burn specs: 318 ci (5.2L) 8-cylinder, 3.909 x 3.311 in (99.3 x 84.1 mm) bore and stroke. Rated 145 hp, 1977.

The Dodge LA 318 2-bbl, Electronic Lean Burn is oversquare — the 3.9094" bore exceeds the 3.311" stroke by 18.1% — a layout that favors airflow and RPM over leverage at the crank. The 3.311" stroke does not reach 4,000 ft/min of mean piston speed until about 7,250 RPM, so piston speed is not what limits this engine's revs — valvetrain and breathing are. A rod ratio of 1.849 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 8 cylinders displaces 39.8 ci (651 cc).

It is one of 15 engines in the Dodge 318ci family, all of them 318 ci — the differences between them are in compression, heads and rating, not displacement.

Dimensions

Displacement318 ci / 5.2 L
Bore3.9094"
Stroke3.311"
Cylinders8
ConfigurationV8
Compression ratio8.5–8.6:1 (published figures vary)
Rod length6.123"
Rod ratio1.849
Bore/stroke ratio1.181

Construction

Block materialcast iron
Head materialcast iron
ValvetrainOHV
Fuel typegas
Firing order1-8-4-3-6-5-7-2
Advertised HP145 hp
Years1977

Factory ratings by year

YearVersionHP @ rpmTorque @ rpmComp.
1977net145 @ 4000——

Factory specification sheet.

What these numbers mean

Bore/stroke character1.181 — oversquare — bore exceeds stroke, which favours higher RPM and larger valves
Mean piston speed at 6,000 RPM3,311 ft/min — conservative for a street engine
Rod ratio1.849 — long — less side loading on the cylinder wall, favours high RPM
Displacement per cylinder39.8 ci

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What cars have the LA 318 2-bbl, Electronic Lean Burn?

9 factory vehicles, 1968–1987. Each year opens that model's engine table.

Similar engines

← All Dodge 318ci engines