The VH45DE is a 4.5 liter V8 developed by Nissan for use in the Infiniti Q45 sport luxury sedan (G50 platform) which was released in November 1989. The engine was also used in the Japanese market Nissan President limousine (JG50 platform) which debuted in late 1990. The VH45DE generates 278 hp (207 kW) at 6000 rpm and 292 lb·ft (396 N·m) at 4000 rpm with a redline of 6900 rpm.
Some of the pertinent features of the VH45DE are:
- Forged steel crankshaft.
- Forged steel connecting rods.
- 6 Bolt main bearing caps with studs.
- Full-length main bearing girdle.
- Lightweight, floating pistons with molybdenum coating.
- Sodium-filled exhaust valves.
- Cross-flow cooling system.
- Hydraulic lash adjusters.
- Single-row silent timing chain.
- Coil-on-plug ignition system.
- Lifter buckets ride directly on cams to reduce friction.
- Redline of 6900 rpm, Or 7400 RPM's with a modified ECU.
- Compression ratio of 10.2 to 1.
- Bore of 93 mm and stroke of 82.7 mm.
- Dimensions: 890 mm(L) x 740 mm(W) x 725 mm(H).
The 4.5 L VH45DE featured variable valve timing, also known as VTC, from 1990 until 1995. This was due to the "Gentleman's Agreement", requiring all imports to produce no more than 280 hp. Nissan got around this by publishing the hp rating without VTC, meaning it's actual power rating is closer to 310 hp and 330 lb·ft. of torque. Due to tightening emissions regulations in the US market, the VTC feature was dropped from the 1996 Infiniti Q45. In the following year, the VH45DE was no longer available in any US market vehicles. The engine continued on in the Japanese market until 2002 in the Nissan President limousine.
The 4.5 L (4494 cc) VK45DE was introduced in 2002 and is built in Yokohama, Japan. Bore is 93 mm (3.7 in) and stroke is 82.7 mm (3.26 in). Output is 340 hp (254 kW) at 6400 rpm with 333 lb·ft (451 Nm) of torque at 4000 rpm. Redline is at 6600 rpm. It has an aluminum engine block and aluminum DOHC cylinder heads. It uses SFI, has 4 valves per cylinder with VVTand features forged steel connecting rods, 4 one-piece cast camshafts, and an unusual variable-flow induction system optimizes airflow for low- and high-speed operation and low-friction molybdenum-coated pistons and microfinished crankshaft.
A flat-plane crankshaft version of the VK45DE is used by Nismo for Super GT races with the Nissan GT-R instead of using the GT-R's VR38DETT twin-turbo V6 engine. The VK45DE was previously used in Nissan's 350Z Super GT car, replacing the previous VQ30DETT used in that car in 2007. In race trim, the Super GT VK45DE produces 500 PS (490 hp) and 52 kg·m (380 ft·lbf) of torque. The engine idles at around 3500 RPM and is restricted to the above specified power output. Without such restrictions, the engine is reputedly capable of producing nearly 800 PS (790 hp). Nismo reasons that by using the engine, they eliminate turbo-lag, save weight and generally prefer the torque curve of the atmospheric V8.