GM 6.2L LT1 Engine Specs, Problems, Reliability, Info

6.2 LT1 Gen5 Small Block V8

The LT1 is a naturally-aspirated 6.2-liter direct-injected V8 gasoline engine, a member of GM's Gen V Small Block engine family. Its debut took place in 2014 with the new Chevrolet Corvette Stingray (seventh generation C7). Nevertheless, it swiftly found its way into other models within the General Motors lineup, including the Chevrolet Camaro SS and Chevrolet Camaro LT1. Although the name “LT1” sounds familiar, this new engine has been significantly redesigned and upgraded compared to previous 5.7-liter models (1970-1972 LT1 Gen I and 1991-1997 LT1 Gen II). In this article, we have tried to gather all the important information about this engine, including its features, specifications, pros and cons.

LT1 Engine Overview

The new 6.2L LT1 is built around an aluminum cylinder block with cast-in iron cylinder liners. It features a 90-degree cylinder angle, 4.400-inch bore centers, a 4.06-inch (103.25 mm) bore and a 3.62-inch (92 mm) stroke (stroke size is the same across all Gen5 small block engines). The LT1 comes with a forged-steel crankshaft located with nodular main bearing caps, I-beam powder-metal 6.098-inch-long connecting rods, and cast aluminum domed pistons with reliefs for the exhaust valve and direct injector. Pistons are also cooled by oil-spraying jets. The LT1 engine is equipped with a dual-pressure control and variable displacement vane oil pump driven by the crankshaft. The Corvette LT1 comes with a dry sump 9.8-quart-capacity oiling system (Z51 Performance Package), or with a wet sump (6.0-quart aluminum oil pan).

This engine features a cam-in-block architecture, which includes a single hydraulic roller-lifter camshaft inside the block, 7.85-inch-long pushrods and roller-pivot rocker arms. On top of the block, there are aluminum OHV 8-valves cylinder heads with high-flow straight, rectangular intake ports and oval-shaped exhaust ports. The hollow-stem intake valve has a diameter of 2.126 inches (54 mm), diameter of the sodium-filled exhaust valves is 1.590 in (40.4 mm). Intake valve angle is 12.5 degrees, exhaust valve angle — 12.0 degrees.

The camshaft comes with a vane-type phaser of the dual-equal camshaft phasing system that adjusts timing at the same rate for both intake and exhaust valves. The cam also has an additional “trilobe” at the back that drives the high-pressure fuel pump for the direct injection combustion system. The camshaft has the following specs: 200/207 duration (int./exh.), 0.551 in./0.524 in. valve lift (int./exh.). Dual-Equal Cam Phasing works together with Active Fuel Management (AFM) technology. The AFM can turn off half of the cylinders when the load is low to save fuel. When the load increases, all eight cylinders are activated again, providing maximum power.

All Gen V engines feature Direct Injection: fuel is injected directly into the combustion chambers, instead of intake ports. This system includes direct fuel injectors and a high-pressure fuel pump, in addition to a conventional fuel pump in the tank. The fuel pressure can reach up to 15 Mpa (150 bar). The HP pump is driven by a camshaft and is located in the valley between two cylinder heads, beneath a high-flow intake manifold made of composite material. The intake manifold is fitted with a drive-by-wire, 4-bolt, electronic throttle body with an 87 mm bore diameter. The LT1 also came with 58X ignition system with individual coils (coil-near-plug) for each iridium-tip spark plug and the latest E92 engine controller.

The End Result

The new 6.2L LT1 Gen V Small Block engine shows impressive power and efficiency. It produces up to 460 hp at 6,000 rpm and 465 lb-ft at 4,600 rpm, while the max engine speed is 6,600. This level of performance and economy makes it possible to compete even with modern supercharged engines. This has made it a popular choice among car enthusiasts who appreciate the balance of dynamics, handling and driving comfort.

Engine Specs

GM 6.2L LT1 Reliability and Longevity

The 6.2L LT1 V8 is generally considered a reliable, strong and powerful engine. However, it is a modern Small Block with GDI, AFM and electronics, so it can experience failures. Here are some of the most common problems that affect these engines:

• Carbon Build-up: The engine may experience accumulation of carbon deposits on intake valves. This is a typical problem for almost every GDI engine.
• AFM System Problems: The AFM system is known to cause excessive oil consumption and lifter problems.
• NHTSA Investigation and a 2021-2024 Vehicle Recall: The recall was made for 6.2L L87 engines and some LT1 engines. Connecting rods and/or crankshafts may have manufacturing flaws, which can lead to a loss of power or even complete engine failure (engine seizure or connecting rod breaching the engine block).
• Spun Bearing and Oil Starvation: A spun bearing is usually the end result of a chain of events, separated from manufacturing defects. Usually, it is caused by oil starvation due to insufficient oil flow or oil contamination. 5W-30 Dexos1 synthetic oil was standard before the recall. Now, GM recommends to use 0W-40 DexosR-certified oil for both street and track applications.

The 6.2-liter LT1 V8 is a reliable and durable engine that can handle significant power. Most problems with LT1 occur due to poor maintenance, aggressive high-RPM driving, and natural wear and tear over significant mileage. So, if you want the engine to last as long as possible, you need to keep it well maintained, use a performance engine oil (change every 5-7k miles) and premium gas only. With this strategy, the 6.2L Gen5 LT1 engine in its stock configuration can last more than 250,000 miles.

LT2 Engine

The LT2 is a successor to the LT1. This 6.2-liter NA small block V8 engine debuted in the 2020 Corvette Stingray, which features a mid-engine layout.

LT4 Engine