GM 7.0 Liter V8 LS7 Engine
The 7.0-liter V8 LS7 is an engine produced by General Motors for use in high-performance vehicles. Being one of a handful of GM engines assembled by hand, the LS7 is part of GM’s 4th-generation V8 Small Block engine family and is notorious for its consistent and smooth power delivery. The LS7 is also one of the most powerful naturally-aspirated engines in the world. It is currently produced for use in a single vehicle — the 2014 Chevrolet Camaro Z/28. Previously, the LS7 was used on the sixth-generation Corvette Z06 and 427 Convertible, both of which are no longer in production, as they have been replaced by the all-new 2015 Corvette Z06.
The LS7 is easily identified under the hood by red engine covers with black lettering. It shares the basic architecture of other Gen IV Small Block V8 engines, but is the largest-displacement variant, featuring pressed-in steel cylinder liners to accommodate the engine’s larger diameter, 4.125-inch (104.8 mm) cylinder bores. It also uses a racing-style dry-sump oiling system that helps ensure adequate oil pressure during high-load cornering.
Each LS7 is assembled by hand by a single builder at GM’s unique Performance Build Center in Wixom, Michigan. The 100,000-square-foot facility weaves the best practices of low-volume niche manufacturers and the established quality and manufacturing standards at GM to ensure the highest-quality specialized engines.
- Cylinder Block: the LS7’s cylinder block shares two key design elements with GM’s original small-block V8: a 90-degree cylinder angle and 4.400-inch bore centers. The LS7 uses unique pressed-in cast iron cylinder liners to accommodate the largest cylinders bores in the engine family. The LS7 block also features very durable, doweled-in, forged-steel main bearing caps, which hold the balanced, forged-steel crankshaft in place and reduce crank flex. The Gen IV block was developed with math-based tools and data acquired in GM’s racing programs, and provides a light, rigid foundation for an impressively-smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine’s structure. A structural oil pan further stiffens the powertrain.
- Deck Plate Honing: a precision machining process typically reserved for high-performance engines is used on the LS7 cylinder block to maximize engine life, reduce friction between engine parts, and increase horsepower. It is advantageous in applications where cylinder head pressures are greater than average – such as with a supercharged engine – to ensure cylinder sealing and prevent scuffing of the piston against the bore wall. In the LS7 engine, this means improved bore life and ring sealing. True bores and better sealing are keys to optimizing power.
- Titanium Connecting Rods: lightweight titanium connecting rods are used in the LS7 to reduce the pressure on the rod end bearings and the main bearings, and allow the bearings to be optimally sized for the least amount of friction. The lightweight rods are matched with pistons that feature tapered wrist pins to reduce weight. The piston rings are anodized to reduce blow-by and friction, while the skirts are coated with a polymer material to limit bore scuffing and reduce noise.
- Racing-Derived Cylinder Heads: the LS7’s large displacement would mean little in terms of horsepower if the engine could not draw in and then expel enough air to take advantage of the powerplant’s size. To that end, the LS7 is fitted with high-flow cylinder heads that are derived from racing heads first proven on the track with the Corvette Racing team. The heads feature fully CNC-machined intake, exhaust ports, and 70cc combustion chambers to reduce airflow restrictions, while the high machining consistency of the machining procedure enable’s the LS7’s high, 11.0:1 compression ratio.
- High-Flow Intake Manifold with Acoustic Shell: the LS7’s intake manifold ports are designed to match the cylinder head. The composite manifold is manufactured with a lost core process to improve runner-to-runner variation and to reduce flow losses. Acoustic foam is sandwiched between the outside top of the intake manifold and an additional “skull cap” acoustic shell to reduce radiated engine noise.
- Dry Sump Oiling System: Corvettes equipped with a manual transmission feature a dry sump oiling system which promotes exceptional lubrication system performance during extended high-rpm use under high cornering loads.
- Advanced Electronic Throttle Control: with ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. The ETC system can deliver outstanding throttle response and greater reliability than a mechanical connection.
- 58X Ignition System: the LS7 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate and accurate information on the crankshaft’s position during rotation, allowing the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.
- Hydroformed Exhaust Manifolds: the exhaust manifolds are made of hydroformed stainless steel, which is lighter than cast iron, and feature a unique four-into-one collector designed to maximize airflow. Exhaust pipes on the LS7-equipped Corvette Z06 are three inches in diameter, compared to the 2.5-inch pipes on Corvettes built with the 6.0L LS2.
|Type:||7.0L Gen IV V8 Small Block|
|Displacement:||7008 cc (427.6 ci)|
|Valve configuration:||Overhead valves|
|Valves per cylinder:||2|
|Assembly site:||Performace Build Center in Wixom, Michigan|
|Valve lifters:||Hydraulic roller|
|Firing order:||1 – 8 – 7 – 2 – 6 – 5 – 4 – 3|
|Bore x stroke:||104.8 X 101.6|
|Bore Center (mm):||111.76|
|Bore Area (cm2) (total engine bore area):||689.75|
|Fuel system:||Sequential fuel injection|
|Fuel Type:||Premium Fuel required|
|Engine Mass (kg/lbs):||206 / 454|
|Horsepower hp (kw)|
|Chevrolet Camaro Z/28:||505 hp (377kW) @ 6100 SAE Certified|
|Chevrolet Corvette Z06/427 Convertible (Discontinued):||505 hp (377kw) @ 6300 RPM SAE Certified|
|Torque lb.-ft. (Nm)|
|Chevrolet Camaro Z/28:||481 lb.-ft. (652Nm) @ 4800 SAE Certified|
|Chevrolet Corvette Z06:||470 lb.-ft. (637Nm) @ 4800 RPM SAE Certified|
|Maximum Engine Speed:||7100 rpm|
|Positive crankcase ventilation|
|Cylinder head:||Cast aluminum|
|Exhaust manifold:||Stainless Steel|
|Main bearing caps:||Forged steel|
|Crankshaft:||Forged 4140 steel|
|Connecting rods:||Forged Titanium|
|Extended life spark plugs|
|Titanium Intake Valves|
|Extended life coolant|
|Oil level sensor|
|Oil Life System|
|Chevrolet Camaro Z/28 (Coupe)||MM6-TR6060|
|Chevrolet Corvette C6 Z06 and 427 Convertible (Discontinued)|