In Australia, the most common Japanese
manufactured V8 is the Toyota/Lexus UZ-series. But Nissan make some bent-eight
motors that are every (cubic?) inch as good. In this article, we take a look at
the evolution of the VH and VK-series engines that range from 4.1 to 5.6-litres
– some real high-tech muscle!
Nissan’s first modern V8 appeared in the Japanese
domestic market during 1989 – not coincidentally, about the same time Toyota
released its UZ-series V8.
The new Nissan V8 was engineered exclusively for
use in large luxury vehicles. The ’89 Infiniti Q45 and ’90 President appeared
with Nissan’s all-alloy 90-degree V8 which is coded VH45DE. The VH45DE employs
an oversquare bore and stroke (93 x 82.7mm) to displace 4494cc – substantially
more than Toyota’s contemporary rival engine. The VH45DE also features DOHC,
four-valve-per-cylinder heads, knock sensing, direct-fire ignition, a 10.2:1
compression ratio, variable inlet cam timing and an unusual looking fixed-volume
intake manifold with a big-bore 75mm throttle and airflow meter. A steel
crankshaft allows the engine to spin safely to its 6700 rpm limiter.
On premium unleaded fuel, the Infiniti Q45-spec
Nissan thumps out the Japanese regulation 206kW max output (at 6000 rpm)
together with a neat 400Nm of torque at 4000 rpm. It is widely believed that
actual output is considerably higher than 206kW. However, the Nissan President
version isn’t quite as gutsy – it musters ‘only’ 198kW at 5600 rpm and 394Nm at
4000 rpm. We believe that the President’s lower output is due to a more
restrictive exhaust system and the lack of variable inlet cam timing – the
compression ratio and all other major engine specs appear identical.
The VH45DE comes equipped with a standard
four-speed automatic transmission and is configured for longitudinal mounting
and rear-wheel-drive. In the Infiniti Q45, this engine/driveline package was
sold into the mid ’90s but it continued to around 2000 in President guise.
In 1991, Nissan released a short-stroke version of
the VH-series V8. With a 73mm stoke, the newly created 4130cc VH41DE engine can
be found in the top-line version of the Japanese Nissan Cima and Leopard saloon.
The VH41 uses much of the same design and hardware as its big brother but with a
slightly higher compression ratio (10.5:1) it trails by a relatively small
margin. Sure, it might be 0.4-litre smaller but this engine is happy to put out
198kW at 6000 rpm and 371Nm at 4400 rpm. Again, a four-speed auto comes attached
and the engine is configured for rear-wheel-drive. An all-wheel-drive version
was also available from 1992 in the Cima.
In mid 1996, the VH41DE received an update and was
introduced in the new-look Y33-series Cima. Peak power was unaltered from 198kW
but is achieved earlier in the rev range (at 5600 rpm). Peak torque is improved
slightly to 377Nm at 4000 rpm. An AWD version of the Cima was introduced in
1997. Interestingly, the Cima was rebadged and sold as the second-generation
Infiniti Q45 in various overseas markets.
Facing tightening emission standards at the start
of the new millenium, Nissan axed the VH-series V8 platform and built a
new VK-series engine based on the design of the late-model VQ-series V6.
The first vehicle to receive VK-series power in
2001 was the top-line Japanese Cima saloon. Interestingly, the VK45 uses the
same bore and stroke dimensions as the VH45DE for a total displacement of
4494cc. Breathing is through DOHC, multi-valve heads and there’s a variable
induction system, variable inlet cam timing, forged steel rods, titanium valves,
aluminium lifters, electronic throttle control and lightweight pistons to
squeeze the compression ratio up to 11:1. The use of direct fuel injection is
also reflected in the engine code – VK45DD.
On premium unleaded fuel, VK45DD matches the
‘smoggy’ VH45DE with a claimed 206kW at 6000 rpm. Peak torque is in favour of
the VK45DD with an impressive 451Nm at 3600 rpm. All this while also meeting LEV
standards! A five-speed auto transmission comes fitted to rear-wheel-drive
models while a four-speed auto is found in all-wheel-drive models.
At around the same time the VK45DD was released, a
non direct-injection version of the VK45 was introduced in the US market – the
VK45DE. The VK45DE is essentially the same as the DD engine except it comes with
a conventional multi-point injection system and a 10.5:1 compression ratio.
Output is 340 bhp (254kW) at 6400 rpm and 333 lb-ft (453Nm) at 4000 rpm. This
engine can be found in the 2002 third-generation US-spec Infiniti Q45. In 2004,
the VH45DE was expanded into the Infiniti FX45, Infiniti M45, Nissan Fuga – in
these vehicles, output varies between 315 bhp and 335bhp (235 – 250kW).
Curiously, it appears that the VK45DE wasn’t sold
in Japan until 2004 when it was introduced to the Cima and President. In
Japanese guise (with a 10.5:1 compression ratio), this engine is conservatively
rated at 206kW at 6000 rpm and 451Nm at 3600 rpm.
And don’t overlook the biggest banger in the
Nissan V8 range – the 5.6-litre VK56DE!
The VK56DE employs a massive 98mm bore and 92mm
stroke for a total displacement of 5552cc. This engine is built in the US and,
as far as we’re aware, is not sold outside of the country. Fitted to the ’04
Nissan Pathfinder Armada and Titan pick-up, this engine makes 305 bhp (227kW) at
a low 4900 rpm and more than 500Nm of torque at 3600 rpm. In the Infiniti QF56
SUV it makes an extra 10 bhp (7kW).
If you live in the US you have access to a great
range of Nissan V8s (including the big 5.6-litre VK56DE) but here in Australia
the most common import Nissan V8s are the early VH45 and VH41. The VH45DE has a
huge amount of tuning potential and a bare engine (minus ECU and loom) can be
picked up at the wreckers for under AUD$2000 – a complete package ranges between
about AUD$2500 – AUD$3000. There are no major reliability problems with these
big-cube motors, so why not be one of the first in Australia to go ballistic
with modification? C’mon - you know you want to!
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