LT4 Engine: Specs, Horsepower, LT4 vs LT1 and LSA, and the LT4 Crate Engine
The LT4 is GM’s supercharged 6.2-liter (376 cubic inch) Gen V small block V8, introduced in the 2015 Chevrolet Corvette Z06 at 650 HP and 650 lb-ft. It pairs direct fuel injection with an Eaton supercharger on an aluminum block, and it has also powered the Camaro ZL1 and Cadillac’s V-series sedans. GM Performance sells it new as a crate engine.
LT4 engine specs
| Specification | LT4 |
|---|---|
| Displacement | 6.2L (376 cubic inches) |
| Family | GM Gen V small block (LT) |
| Bore x stroke | 4.065″ x 3.622″ |
| Block and heads | Aluminum |
| Supercharger | Eaton R1740 TVS (1.7 liter) with intercooler |
| Compression ratio | 10.0:1 |
| Fuel system | Direct injection |
| Valvetrain | Pushrod, two valves per cylinder, titanium intake valves, variable valve timing |
| Rotating assembly | Forged steel crankshaft, forged aluminum pistons |
| Factory rating | 650 HP and 650 lb-ft (Corvette Z06, Camaro ZL1) |
How much horsepower does an LT4 make?
GM rated the LT4 at 650 HP and 650 lb-ft in the 2015 to 2019 Corvette Z06 and in the Camaro ZL1. Cadillac’s versions were rated at 640 HP in the CTS-V and 668 HP in the CT5-V Blackwing. The GM Performance LT4 crate engine (part 19431955) is rated at 650 HP.
LT4 vs LT1
| LT1 (Gen V) | LT4 | |
|---|---|---|
| Displacement | 6.2L (376 ci) | 6.2L (376 ci) |
| Induction | Naturally aspirated | Eaton supercharger with intercooler |
| Compression ratio | 11.5:1 | 10.0:1 |
| Fuel system | Direct injection | Direct injection |
| Factory rating | 455 HP (Corvette Stingray, Camaro SS) | 650 HP (Corvette Z06, Camaro ZL1) |
The two engines share their bore, stroke and basic Gen V architecture. The LT4 lowers compression for boost and adds forged aluminum pistons, titanium intake valves and the supercharger. We do not sell the LT1; for its Gen IV predecessor, see our LS3 engine guide.
LT4 vs LSA
The LSA is the supercharged 6.2L from the previous Gen IV (LS) family, rated at 556 HP in the 2009 to 2015 Cadillac CTS-V and 580 HP in the 2012 to 2015 Camaro ZL1. It uses port fuel injection and a larger 1.9-liter Eaton supercharger. The LT4 moved to the Gen V design with direct injection, a more compact 1.7-liter supercharger and 650 HP. LSA parts are not interchangeable with the LT4. If you are building a supercharged LS instead, the GM Performance 6.2L LSA aluminum block is available bare.
LT4 vs LT5 and LS3
- LT5: the engine of the 2019 Corvette ZR1, rated at 755 HP and 715 lb-ft. It adds port injection to direct injection and uses a larger supercharger than the LT4.
- LS3: GM’s naturally aspirated 6.2L Gen IV engine with port injection, rated at 430 HP in the Corvette. It is simpler to swap and wire, but makes far less power than an LT4.
Not to be confused with the 1996-97 LT4
GM also used the LT4 name for a 5.7L Gen II small block in the 1996 Corvette Grand Sport and manual-transmission 1996 to 1997 Corvettes, rated at 330 HP. It is a completely different engine from the supercharged LT4 described here.
Swapping an LT4 crate engine
An LT4 swap needs more than an LS swap:
- Engine control: a controller and harness made for the LT4. Check whether the listing includes one before you order.
- Fuel system: direct injection uses an engine-driven high-pressure pump, which must be fed by a suitable in-tank low-pressure pump and lines.
- Intercooler cooling: the supercharger’s intercooler runs on its own coolant circuit, with a pump and front-mounted heat exchanger.
- Oil pan: the factory pans often do not clear older chassis. The Moroso GM LT engine swap oil pan is an 8-quart, center-sump aluminum pan made for Gen V LT engines.
- Accessories and transmission: an accessory drive that fits your engine bay and a transmission rated for the torque.
See all LS and LT crate engines and oiling systems. The LT4 crate engine is $19,745.46, with flat $75 shipping to any US state.
Frequently asked questions
Is the LT4 a 6.2?
Yes. The LT4 displaces 6.2 liters, or 376 cubic inches, from a 4.065″ bore and 3.622″ stroke.
How much horsepower does an LT4 have?
GM rated it at 650 HP and 650 lb-ft in the Corvette Z06 and Camaro ZL1. The GM Performance LT4 crate engine we list is rated at 650 HP.
What is the difference between the LT1 and the LT4?
Both are 6.2L Gen V V8s with direct injection. The LT4 adds an Eaton supercharger, forged pistons and titanium intake valves, and lowers compression from 11.5:1 to 10.0:1, raising output from 455 HP to 650 HP.
Is the LT4 the same as the LSA?
No. The LSA is a supercharged Gen IV LS engine with port injection, rated at 556 to 580 HP. The LT4 is a Gen V engine with direct injection and a different supercharger, rated at 650 HP.
What supercharger does the LT4 use?
An Eaton R1740 TVS, a 1.7-liter Roots-type supercharger, used with an air-to-water intercooler.
What is the compression ratio of an LT4?
10.0:1.
Related: LS3 engine, GM LS engines explained, LSX engine, LS swap guide, crate engine prices, LT4 crate engine, all guides.
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