GM High Feature engine
The GM High Feature engine (also known as the HFV6, and including the 3600 LY7 and derivative LP1) is a family of modern DOHC V6 engines produced by General Motors. The series was introduced in 2004 with the Cadillac CTS and the Holden Commodore (VZ).
It is a 60° 24-valve design with aluminum block and heads and sequential multi-port fuel injection. Most versions feature continuously variable cam phasing on both intake and exhaust valves and electronic throttle control. Other features include piston oil-jet capability, forged and fillet rolled crankshaft, sinter forged connecting rods, a variable-length intake manifold, twin knock control sensors and coil-on-plug ignition. It was developed by the same international team responsible for the Ecotec, including the Opel engineers responsible for the 54° V6, with involvement with design and development engineering from Ricardo plc.
GM's Australian auto division Holden produced a HFV6 engine under the name "Alloytec."
History
The HFV6 was designed, tested, and produced in a joint program by Holden and Cadillac. A majority of designs into the new alloy construction, transmission pairing, and first use in production were all undertaken in Detroit (and manufactured in St. Catharines, Ontario). Holden was charged with developing smaller engines (Holden 3.2 LP1 and Saab 2.8 Turbo LP9) as well as their own Holden 3.6 and 3.0 HFV6 (called the Alloytec V6) for local models.
Cadillac and Holden both tested variations of these engines in the United States and Australia.
2.8
LP1
A 2.8 L (2,792 cc) LP1 variant was introduced in the 2005 Cadillac CTS. It was also used on the Chinese 2008 CTS. It has a 89 mm × 74.8 mm (3.50 in × 2.94 in) bore and stroke, sequential multi-port fuel injection and a 10.0:1 compression ratio. The LP1 was built in St. Catharines, Ontario.
Applications:
LP9

This engine is also known as a A28NET, Z28NET, Z28NEL or B284.
The LP9 is a 2.8L turbocharged version used for the Saab 9-3, Saab 9-5, and other GM vehicles. It has the same bore and stroke as the naturally aspirated LP1, however the compression ratio is reduced to 9.5:1. The engine is manufactured at Holden's Fishermans Bend engine factory in Port Melbourne, Australia, while GM Powertrain Sweden (formerly Saab Automobile Powertrain) is responsible for turbocharging the engine. Global versions of this engine use the same horsepower rating for both metric and imperial markets – mechanical horsepower – while the Europe-only versions are rated in metric horsepower.
Applications:
LAU
The LAU is GM's new code for the LP9 Turbo engine, its usage starting with the 2010 Cadillac SRX. In 2011, production of the Cadillac SRX with the LAU engine ceased, but the engine remained in use in the Saab 9-4X until 2012, when production of that model came to an end.
Applications:
3.0
LF1
The LF1 is a 3.0-litre (2,994 cc) version with a bore and stroke of 89 mm × 80.3 mm (3.50 in × 3.16 in) produced between 2010 and 2014, equipped with spark ignition direct injection (SIDI) and a 11.7:1 compression ratio.
Applications:
LFW
The LFW is a flexible fuel version of the LF1, capable of running on E85, gasoline, or any mixture of the two. Output is identical to the LF1.
Applications:
3.2
Holden has built its own 3.2 L (3,195 cc) version of the High Feature engine in Australia produced between 2005 and 2010 with a bore and stroke of 89 mm × 85.6 mm (3.50 in × 3.37 in). Branded with the Alloytec name like the 3.6L version, this version produces 227 hp (169 kW; 230 PS) at 6600 rpm and 297 N⋅m (219 lb⋅ft) at 3200 rpm. It has a 10.3:1 compression ratio. Its fuel economy is 4–6 km/L (11–17 mpg‑imp; 9.4–14.1 mpg‑US) in city, and 7–9 km/L (20–25 mpg‑imp; 16–21 mpg‑US) on highway.. Holden also produced the 3.2L engines that were used by Alfa Romeo as the basis of its JTS V6 engine.
Applications:
- 2006-2010 Daewoo Winstorm / Chevrolet Captiva / Holden Captiva
- 2006-2010 Opel Antara / Daewoo Winstorm MaXX / Holden Captiva MaXX
- 2008-2012 Suzuki Grand Vitara
3.6
LY7
The 3.6 L; 217.5 cu in (3,564 cc) LY7 engine was developed primarily by Holden and introduced in the 2004 Holden VZ Commodore and 2004 Cadillac CTS sedan. It has a 10.2:1 compression ratio, Sequential multi-port fuel injection, and a bore and stroke of 94 mm × 85.6 mm (3.70 in × 3.37 in). Lower-powered versions only have variable cam phasing on the inlet cam (LE0). Selected models also include variable exhaust. The engine weighs 370 lb (170 kg) as installed.
This engine is produced in several locations: St. Catharines (Ontario), Flint Engine South (Michigan), Melbourne (Australia), Ramos Arizpe (Mexico), and Sagara (Japan) by Suzuki.
Suzuki's engine designation is N36A.
The dual-fuel 235 hp (175 kW; 238 PS) LW2 version was able to run on petrol and autogas. The LW2 engine was based on the low-output LE0 V6. It featured a factory-fitted dual-fuel system developed by IMPCO, different valves, and hardened titanium valve seats. This motor was available exclusively in Holden vehicles from 2005–2012.
Applications:
LLT
The 3.6 L (3,564 cc) LLT is a direct injected version based on the earlier LY7 engine. It was first unveiled in May 2006, and the DI version was claimed to have 15% greater power, 8% greater torque, and 3% better fuel economy than its port-injected counterpart. The LLT engine has a compression ratio of 11.3:1, and has been certified by the SAE to produce 302 hp (225 kW; 306 PS) at 6300 rpm and 272 lb⋅ft (369 N⋅m) of torque at 5200 rpm on regular unleaded (87 octane) gasoline. This engine debuted on the 2008 Cadillac STS and CTS. GM used an LLT in all 2009–2017 Lambda-derived crossover SUVs to allow class-leading fuel economy in light of the new Corporate Average Fuel Economy (CAFE) standards. In these crossovers, the LLT engine produced up to 288 hp (215 kW; 292 PS) and 270 lb⋅ft (366 N⋅m) of torque.
Applications:
LFX
The LFX is an enhanced version of the LLT engine developed jointly by Holden and Cadillac. Introduced in the MY2012 Holden Commodore SV6 and the MY2012 Chevrolet Camaro LS/LT, it is 20.5 pounds (9.3 kg) lighter than the LLT, thanks to a redesigned cylinder head, integrated exhaust manifold, and composite intake manifold. Other components like the timing chains, fuel injectors, intake valves, and fuel pump have also been updated. They also updated the cam phasing and variable valve timing system compared to the LLT. Power and torque are up slightly from the LLT. The compression ratio is 11.5:1. The LFX also features E85 flex-fuel capability.
Applications:
LWR
The LWR is dedicated LPG 3.6-liter engine. Introduced in the MY2012 Holden Commodore, Based on the 3.6-litre LY7 engine, the LWR had a vapour injection system. The vapour injection system injected gas directly into the air intake runner, thereby preventing excess gas from circulating through the air intake system. Although liquid LPG injection generally produces more power, Holden justified vapour injection on the grounds of lower fuel consumption, lower CO2 emissions, reduced pumping and parasitic losses, and start-up reliability in hot weather.
The dedicated LPG LWR engine produced peak power and torque of 180 kW (245 PS; 241 hp) at 6000 rpm and 320 N⋅m (236 lb⋅ft) at 2000 rpm. The LWR engine was mated to GM's six-speed 6L45 automatic transmission and, over the combined ADR 81/02 test cycle, the Commodore Omega achieved fuel consumption of 11.8 L/100 km (24 mpg‑imp; 19.9 mpg‑US) – an improvement of 1.6 L/100 km compared to its dual-fuel LW2 predecessor. Furthermore, the LWR engine exceeded Euro 6 emissions standards.
- Specially hardened valves and valve seats.
- A redesigned cylinder head and manifold for improved air flow.
- Variable exhaust valve timing (the LW2 engine only had variable intake valve timing)
- Specially-developed fuel injectors.
- New pistons with pentroof-style centre-domes and valve eyelets for a higher compression ratio of 12.2:1 (compared to 10.2:1 for the dual fuel engine).
- A new fuel rail and a new LPG fuel filter.
Applications:
LCS
The 3.6 L (3,564 cc) LCS was derived from the direct-injected LLT for use in hybrids, using the two-mode system. Differences from the LLT included a slightly lower compression ratio, 11.3:1, and lower power and torque peaks. It was to debut in the 2009 Saturn Vue Hybrid, where it would have made 262 hp (195 kW; 266 PS) at 6100 rpm and 250 lb⋅ft (339 N⋅m) of torque at 4800 rpm. Fuel economy ratings would have been 6–8 km/L (17–23 mpg‑imp; 14–19 mpg‑US) in city, and 9–11 km/L (25–31 mpg‑imp; 21–26 mpg‑US) on highway. However, GM cancelled its plans for the Saturn Vue Hybrid.
LF3
The 3.6L twin-turbocharged version for the 2014 Cadillac CTS and XTS was announced at the 2013 NYAS.
The engine is rated at 420 hp (313 kW; 426 PS) of power at 5750 rpm and 430 lb⋅ft (583 N⋅m) of torque at 3500–4500 rpm (with 90% of torque being available at 2500–5500 rpm) and helps the CTS achieve 0–60 mph (0–97 km/h) time of 4.6 seconds with an 8-speed automatic transmission.
In essence, the twin-turbo 3.6L V6 is the forced-induction variant of the popular LFX V6 found in the Cadillac ATS, XTS, and SRX, among many other GM models, with several important upgrades, including:
- All-new cylinder block casting
- All-new cylinder head castings
- Strengthened connecting rods
- Forged steel crankshaft
- Continuously variable valve timing
- Large 38.3 mm (1.51 in) intake valves and 30.6 mm (1.20 in) sodium-filled exhaust valves
- Machined, domed aluminum pistons with top steel ring carrier for greater strength
- 10.2:1 compression ratio
- Patented, integrated charge air cooler system with low-volume air ducts
- Twin turbochargers produce more than 12 psi (83 kPa)
- Vacuum-actuated wastegates with electronic control valves
- All-new direct injection fuel system
- Tuned air inlet and outlet resonators, aluminum cam covers, and other features that contribute to exceptional quietness and smoothness
Applications:
LF4
The LF4 is a higher-performance variant of the LF3 for use in the Cadillac ATS-V and Cadillac CT4-V Blackwing. Changes to the LF3 include:
- Turbochargers with low-inertia titanium-aluminide turbines and vacuum-actuated wastegates for more responsive torque production
- Compressors matched for peak efficiency at peak power levels, for optimal track performance
- Patent-pending low-volume charge-cooling system that optimizes packaging efficiency and maximizes boost pressure
- To compliment the quick spooling turbochargers, lightweight titanium connecting rods that reduce inertia of the rotating assembly were used on all ATS-V models, while only manual transmission CT4-V Blackwing models featured titanium connecting rods. 10-speed automatic CT4-V Blackwing models featured steel connecting rods.
- Peak boost increased to 18 psi (1.2 bar), from 12 psi (0.83 bar)
- Higher-flow fuel injectors
- Oil pan baffling for better oil flow at high cornering speeds
Applications:
LFR
The LFR is a bi-fuel variant of the LFX, although multi-point fuel injection is used for both the gasoline and CNG instead of direct-injection.
Applications:
LFY
The LFY is similar to the LFX, but adds stop-start technology and has improved airflow.
Applications:
Fourth generation
Starting with the 2016 Cadillac models, a new generation of High Feature V6s were developed. These new engines have redesigned block architectures with bore centers increased from 103 mm (4.055 in) on prior HFV6 engines to 106 mm (4.173 in) and a redesigned cooling system to target the hottest areas while also facilitating faster warm-up. They also incorporate engine start-stop technology, cylinder-deactivation, 2-stage oil pumps, and updated variable valve timing featuring intermediate park technology for late-intake valve closure. Both engines debuted in the 2016 Cadillac CT6.
3.0 L
LGW
Bore and stroke of 86 mm × 85.8 mm (3.39 in × 3.38 in) are used, along with a 9.8:1 compression ratio and twin turbos with titanium-aluminide turbine wheels. Maximum engine speed is 6500 RPM. Premium unleaded fuel is required.
Applications:
LGY
Bore and stroke of 86 mm × 85.8 mm (3.39 in × 3.38 in) are used, along with a 9.8:1 compression ratio and twin turbos with titanium-aluminide turbine wheels. Maximum engine speed is 6500 RPM. Premium unleaded fuel is required.
Applications:
3.6 L
LGX
Along with the increased bore spacing, the new 3.6 L DI V6 has larger bores than before, growing from 94 mm (3.701 in) to 95 mm (3.740 in) with the same 85.8 mm (3.378 in) stroke as the 3.0L LGW, for a displacement of 3.6 L (3,649 cc). Intake and exhaust valves are also increased in size along with other changes to the cylinder head. The only part shared with the prior generation is the hydraulic lash adjusters in the valvetrain. The LGX was benchmarked against the 3.7L VQ37VHR of the 2015 Infiniti Q40. Compression ratio is 11.5:1 and maximum engine speed is 7200 RPM.
Compared to GM's LFX/LFY 3.6 L engine, the LGX features active fuel management, NVH enhancements and slightly more torque.
The LGX was on Ward's 10 Best Engines for 2016.
Applications:
LGZ
The LGZ is a variant of the LGX designed for use in the Chevrolet Colorado and GMC Canyon.
Applications:
7.2L V12
On March 21, 2007, AutoWeek reported that GM was planning to develop a 60-degree V12 based on this engine family to power the top version of Cadillac's upcoming flagship sedan. This Cadillac would essentially have had two 3.6L High Feature V6s attached crankshaft-to-crankshaft and would have featured high-end technologies including direct injection and cylinder deactivation. If this engine were developed, it would have displaced 7.2 liters, and produced approximately 600 hp (447 kW; 608 PS) and 540 lb⋅ft (732 N⋅m) of torque. Development of the engine was reportedly being conducted in Australia by Holden, with a potential HSV or Statesman application.
In August 2008, GM announced that development of the V12 had been cancelled.
Timing chain issues
Earlier production 2.8L, 3.0L, 3.2L, and 3.6L engines with the three chain design suffered from premature timing chain failures because of a faulty PCV system and extended oil change intervals. Most of the problems occurred on pre-LFX engines.
Holden High Feature engine
Holden sold a HFV6 engine under the name Alloytec. The High Feature moniker on the Holden produced engine is reserved for the twin cam phasing high output version. The block was designed to be expandable from 2.8 L to 4.0 L. High Feature V6 engines were previously produced in Fishermans Bend, Port Melbourne, Australia, and remain in production at the following four manufacturing locations: St. Catharines Engine Plant, St. Catharines, Canada; Flint Engine South in Flint, Michigan, United States; Romulus Engine Plant in Romulus, Michigan; and Ramos Arizpe, Coahuila, Mexico. The assembly lines for the St. Catharines and Flint facilities were manufactured by Hirata Corporation at its powertrain facility in Kumamoto, Japan. Most of the designs of this motor happened in Flint. They were first produced for the Cadillac range. The engine block and cylinder heads are cast at Defiance Foundry in Defiance, Ohio.
References
External links
- Technical article from AutoSpeed
- GM Unveils New Direct Injection V-6 - Ward's Auto World
- WebWombat article
- http://www.gminsidenews.com/index.php?page=Engine_Guide
- http://www.chevrolet.com/impala-4-door-sedan.html
- https://web.archive.org/web/20140109174626/http://www.chevrolet.com/2013-traverse-crossover-suv.html