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GM Vortec 5700 V8 Marine Engine

GM Vortec 5700

General Motors Marine Engines

Vortec, a contraction of "vortex" and "high-tech," refers to the swirling air/fuel mixture that flows into specially constructed cylinder heads.

The Vortec trademark first appeared back in 1988 on a 4.3-Liter, V-6 gas engine that created a vortex of swirling air and fuel in its combustion chambers promoting a better mix of air/fuel. The crate engines are sold to Volvo Penta, MerCruiser, Indmar, and PleasureCraft Marine, who marinize long blocks by adding intake and exhaust manifolds, either a carburetor or fuel injection and marine grade starter and alternator. The 292 horsepower Vortec 5700 displaces 5.7 liters, or 350 cubic inches.

Vortec is the Trademarked Name For a Line of General Motors Engines

Commonly known as "Gen I+" engines this generation of General Motors-based marine V-6s and V-8s ran quieter and offered more reliable operation bolstered by a 10 to 15 percent higher output. Beyond durability and raw power, the biggest attraction for boaters was the flatter torque curve. Gen I+ horsepower is spread up and down the rpm band, instead of being lumped together at the top end. This nets a healthier mid-range, which translates into more usable power to hold plane at lower speeds in order to better negotiate rough water. Another plus is that Gen I+ marine engines were available in both carbureted and electronic-fuel-injected (EFI) versions.All the engine builders had least one Gen I+ in their lineups.

Type 5.7L V-8 Gen 1e Small Block
Displacement 5736 cc
Engine Orientation Longitudinal
Compression Ratio 9.4:1
Valve Configuration Overhead valves (2 valves per cylinder)
Assembly Sites Toluca, Mexico
Valve Lifters Hydraulic roller
Firing Order 1 – 8 – 4 – 3 – 6 – 5 – 7 – 2
Bore x Stroke 101.60 x 88.39 mm
Fuel Type LP & CNG
Horsepower: 216 hp (161 kW) @ 4000 rpm (LP)
196 hp (146 kW) @ 4000 rpm (CNG)
Torque: 308 lb-ft (418 Nm) @ 1400 rpm (LP)
283 lb-ft (384 Nm) @ 1600 rpm (CNG)
Fuel Shutoff N/A
Shipping Weight 432 lb (196 kg)
Emissions Controls Positive crankcase ventilation
Block Cast Iron GM232-M
Cylinder Head Cast iron
Intake Manifold None
Exhaust Manifold None
Main Bearing Caps Cast iron GM232-M
Crankshaft Nodular Iron
Camshaft 5150 steel billet
Connecting Rods Forged - SAE 1141