Chevrolet Gen V LT LT1, LT2, LT4, LT5 - the direct injection era
The modern small-block with direct injection. C7 Corvette Stingray (LT1), C7 Z06 (LT4), 2019 C7 ZR1 (LT5) and C8 Corvette (LT2). 11.5:1 compression on the NA versions, Eaton supercharger on the LT4 and LT5. Aluminium block with a 9.240″ deck height, AFM/DFM cylinder deactivation on the truck variants.
The Gen V LT is not an LS with direct injection. It has a new head design, a new piston design, a new reluctor, a new fuel system and a new software stack. Many bottom-end parts are interchangeable with the LS Gen IV, but the heads, pistons and injector are not. For engine builders that means the Gen V demands specialist knowledge - LS experience does not carry all the way.
For the enthusiast scene the Gen V is still too new to be a classic. We mostly see them from C7 Z06 owners with track-related problems and LT1 Camaro SS after 100 000+ km with carbon buildup on the intake valves. For general service info, see our V8 engine reconditioning page.
Gen V LT variants
| Variant | Year | Displacement | Power | Comp. | Application |
|---|---|---|---|---|---|
| LT1 | 2014-2024 | 6.2L (376 ci) | 455-460 hk | 11.5:1 | C7 Stingray, 2016-19 Camaro SS |
| LT2 | 2020+ | 6.2L (376 ci) | 495 hk | 11.5:1 | C8 Corvette mid-engine |
| LT4 Supercharged | 2015+ | 6.2L SC | 640-650 hk | 10.0:1 | C7 Z06, Camaro ZL1, CT5-V Blackwing, Escalade-V |
| LT5 Supercharged | 2019 | 6.2L SC | 755 hk | 10.0:1 | C7 Corvette ZR1 (limited 2019) |
| L83 / L8B | 2014+ | 5.3L EcoTec3 | 355-383 hk | 11.0:1 | Silverado, Tahoe, Suburban |
| L86 / L87 | 2014+ | 6.2L EcoTec3 | 420-450 hk | 11.5:1 | Silverado HD, Tahoe, Yukon |
| L84 | 2019+ | 5.3L EcoTec3 + DFM | 355 hk | 11.0:1 | Silverado/Tahoe 2019+ |
Difference between the LT5 Gen V (2019) and the LT5 Gen II ZR-1 (1990-95): Completely different engines. The Gen II LT5 was a Mercury Marine-built quad-cam exotic for the C4 ZR-1. The Gen V LT5 is a pushrod V8 with direct injection + an Eaton 2.65L blower + supplemental port injection. Nothing in common except the “LT5” name.
Direct injection - how does it work and why does it cause problems?
On port-injection engines (LS, LT1 Gen II, Gen I MPFI) the injectors spray fuel into the intake runner - the fuel washes the intake valves every cycle. On direct injection engines the injectors spray straight into the combustion chamber at around 2200 psi. The result: nothing washes the intake valves.
Carbon from the PCV system's oil mist builds up on the intake valve heads after 60 000-100 000 km. Symptoms: misfire codes, a rough idle, power loss, a poor cold start. This is not unique to the Gen V LT - every DI engine (BMW N54, VW EA888, Audi FSI) has the same problem. The difference is that GM's Gen V seems to get it faster than some competitors.
Fix: Walnut blasting every 80 000 km - we blast crushed walnut shells through the intake ports to scrub off the carbon without damaging the valve heads. Or, as prevention: a catch can between the PCV and the intake to trap the oil mist before it vapourises in.
Differences between the Gen V LT and the Gen IV LS3
| Feature | Gen V LT (2014+) | Gen IV LS3 / LSA |
|---|---|---|
| Fuel injection | Direct (in cyl head) | Port (i intake runner) |
| Fuel pressure | ~2200 psi DI | ~58 psi MPFI |
| Cylinder head | New port design + DI injector bore | LS3 rect port (intake) |
| Piston design | Recessed crown för DI spray-cone | Flat-top |
| Reluctor (crank) | 58X (modern) | 24X (Gen III/IV LS) |
| Oil pump | Variable capacity (some) | Fixed-displacement |
| Coil-on-plug | Per cylinder (same as LS) | Per cyl |
| Spark plug position | Centred in the chamber | Side of the chamber |
| HPFP | Cam-driven high-pressure pump | Not applicable |
Gen V LT torque specs
Verified against the Summit Racing Knowledge Base SR-05492 and the Michigan Motorsports LT spec. All bolts are TTY - replace them at every teardown.
Cylinder head (M12 TTY)
Main bearings (6-bolt main)
Note - inner main angle 110°: Differs from the Gen III/IV LS, which uses + 80°. The Gen V has 30° more angle on the inner main. Use the LT-specific spec, not the LS spec.
Connecting rod bolts
Harmonic balancer (complex 4-stage)
Note - no impact wrench on the balancer: The complex loose-and-retighten procedure protects the crankshaft from overload. An impact wrench gives incorrect stretch and can damage the crank keyway.
Intake, exhaust, valve cover, oil pan
Transmission
Common faults on the Gen V LT
Direct injection carbon buildup on the intake valves
All DI engines • High- Symptoms
- Misfire codes (P0301-P0308) after 60 000-100 000 km, a rough idle, a poor cold start, power loss across the whole rev range.
- Cause
- DI sprays fuel straight into the combustion chamber - the intake valves are never washed. The PCV system's oil mist condenses and builds carbon up on the valve heads.
Fix: Walnut blasting every 80 000 km. We remove the intake, block off the exhaust ports and blast crushed walnut shells through the intake ports under vacuum. Takes around 4-6 hours. We do this as part of a cylinder head reconditioning or as a standalone service.
HPFP cam lobe failure
LT1 100 000+ km • High- Symptoms
- P0087 lean code (low fuel pressure), the engine drops into “reduced power” mode, poor acceleration.
- Cause
- The HPFP (high-pressure fuel pump) is driven by a dedicated lobe on the camshaft. The lobe wears over time - a worn lobe gives a shorter pump stroke and lower fuel pressure. Common on the LT1 after 150 000 km.
Fix: Replace the HPFP + inspect the cam lobe. If worn: replace the cam (which means lifting the head). Since you are already in there, do the walnut blasting at the same time. We carry out cam grinding to our own profile and combine it with a cylinder head reconditioning.
DFM 17-cyl mode lifter collapse
L84 truck • High- Symptoms
- Ticking, misfire codes, “reduced power” mode.
- Cause
- Dynamic Fuel Management (DFM) is AFM's successor - it uses 17 different cylinder combinations instead of AFM's fixed 4-cylinder mode. More frequent cycle switches = faster lifter wear.
Fix: Same as the AFM fix - a DFM delete kit + non-DFM cam + new lifters + ECU update. We swap the cam (our own cam grinding) and set up the software.
Wet-sump oil starvation på track (C7 Z06 LT4)
Track day • Critical- Symptoms
- Oil pressure drop in hard cornering, oil starvation message, a seized engine.
- Cause
- The C7 Z06 wet-sump LT4 is not built for sustained track use. A GM TSB recommends limited sessions. Many Z06 engines have let go on Nürburgring/Spa visits.
Fix: An Accusump for track use, a dry-sump conversion (expensive), or choose a C7 Z06 with the dry-sump option (Z07 package).
Oil consumption 5.3L L83 (AFM)
Truck 5.3L • Medium- Symptoms
- 1 qt per 1500 km, blue smoke, oil mist from the PCV.
- Cause
- The same piston ring + PCV system issue as the LS-era 5.3L. AFM accelerates the wear.
Head gasket & deck warpage
Overheated engines • High- Symptoms
- Coolant in the oil, white smoke from the exhaust, over-pressure in the expansion tank.
- Cause
- The aluminium head + aluminium block expand at different rates. Overheating warps the deck of the block - which needs measuring and usually resurfacing before a new gasket goes on.
Crank bearing & bottom-end wear (high mileage)
200 000+ km • Medium- Symptoms
- Low oil pressure when hot, knocking from the bottom end under load, metal flakes at the oil change.
- Cause
- Normal wear of the crankshaft main journals and big-end bearings after high mileage. On the LT4 + supercharger the loads are higher.
Gen V LT problems? Carbon? HPFP? AFM?
Direct injection rebuilds demand specialist knowledge. We have the equipment for walnut blasting and DI systems. Call us or send in a quote request. You can ship the engine or part to us by post, or bring it to our workshop in Tyreso.