--- In [email protected], nablusoss1008 wrote:
>
>
>
> --- In [email protected], doctordumbass@ wrote:
> >
> > er, I was serious about the Jaguar...hope Girish reads this.
>
> Oh, I'm sure he does :-)
> Like Maharishi I doubt he's into expensive cars though, and anyways a
Jag is prone to rusting, isn't it ? I doubt a Jag would last very long
in India. I've seen 3 year old Lee Enfield's in Kerala that looked like
they were 30 years due to rust.
> That's why used Jag's imported from Califoria is very popular in
Europe since they have have a reputation for being close to rust-free !
>
As long as they stay away from salt, a Jag won't rust - and you can
purchase a $70K auto for 12K, used. e. g. Full leather interior, heated
seats, walnut burl dash, power on demand, 290 hp mated to a six speed
(five forward) German transmission, and a body as lovely as any
sculpture. Beautiful cars.
For any motor-heads here, what follows is a white paper on the then
newly designed V8 for the 1996 XK8. (I have a 1997 coupe):
JAGUAR'S FIRST V8 ENGINE:
WORLD-CLASS PERFORMANCE, LUXURY-CLASS REFINEMENT
Extending Jaguar's tradition of introducing engine designs first in its
sports car range, the 1997 XK8 debuts with an all-new V8 powertrain
exclusive to the model. Designed entirely by Jaguar and manufactured in
a dedicated facility in the United Kingdom, this 4.0-liter V8 was
engineered to provide refined power.
Designated AJ-V8 inside the company, the engine achieves class
leadership in both power output and refinement. At introduction, Jaguar
claims best-in-class performance in a variety of measures, including
specific power output, weight (441 pounds), power density (engine weight
versus power), powertrain rigidity and friction levels. Variable cam
phasing helps deliver a minimum of 80 percent of peak torque between
1400 and 6400 rpm, giving responsive performance across a wide range of
speeds. A patented high-velocity cooling system helps achieve very fast
warm-up, which in turn improves fuel economy.
"This clean-sheet engine design is destined to be ranked alongside the
XK-series sixes as a benchmark for responsiveness and engineering
brilliance," said Jaguar Cars North America President Michael H. Dale.
"It continues a long tradition at Jaguar for designing engines that stir
the soul at peak rpm and deliver the broad power range that makes
driving an absolute joy."
The Mission: Refined Power
When the V8 engine design program began, all the binders full of
technical requirements and the volumes of market research were distilled
to a mission statement of just two words: Refined Power.
"Today, customers take for granted that the engine of every new car,
like the car itself, will be both reliable and unfailingly smooth," Dale
said. "The AJ-V8 meets those requirements with ease, yet it also
provides impressive torque, effortless acceleration and a silky
smoothness befitting a Jaguar."
XK8 owners will appreciate the considerations built into the AJ-V8 that
reduce or eliminate maintenance. Oil and filter service is at
10,000-mile intervals. Thanks to the use of platinum-tipped spark plugs
and chain drive for the camshafts, there is no scheduled engine
maintenance needed for the first 100,000 miles aside from oil and filter
changes
AJ-V8 Overview
The AJ-V8 is an all-aluminum, double-overhead camshaft,
four-valve-per-cylinder engine with a displacement of 4.0 liters.
Maximum output is 290 horsepower at 6,100 rpm and 284 pounds feet of
torque at 4,200 rpm. It is the first V8 engine designed by Jaguar, and
just the fourth all-new engine in the company's history.
Jaguar research shows that in the current competitive environment, a V8
is the design best able to meet the expectations of buyers in the
prestige-automobile segment.
Beyond market demand, the AJ-V8 also strikes an intelligent balance: It
delivers very high power from a light and compact package. The AJ-V8 is
approximately 12 inches shorter than Jaguar's AJ16 in-line six-cylinder
engine.
Engineering centered on delivering extraordinary smoothness, and the
AJ-V8 actually betters the fuel efficiency of existing six-cylinder
engines of equivalent displacement.
Thorough But Rapid Development
The engineering studies that eventually led to the AJ-V8 began in the
mid-1980s. The core design team, established in 1989, produced the first
running prototype in November 1991.
Rigorous competitive benchmarking, together with data from market
research, led to performance targets for quality, power, smoothness,
fuel efficiency, weight and size.
>From their earliest discussions, the engineering team focused on making
uncompromised quality an intrinsic part of the product. That objective
went well beyond designing an engine that would give a long service
life. It also meant eliminating every source of repeated, bothersome
problems that can emerge throughout an engine's life. To achieve this,
they established simultaneous engineering teams -- 17 in all by the end
of the project -- to coordinate every phase of design and manufacturing.
These cross-functional teams brought together engineers from many
departments with varied backgrounds, pooling their knowledge. By
assigning design and development tasks to teams working in parallel and
establishing communication links, the engine program shrunk to just 36
months from the time of approval to production.
Another key to delivering a powertrain with leading-edge technology was
identifying component suppliers with reputations for best-in-world
quality and innovation. By involving them at the earliest possible
stages, Jaguar took full advantage of their expertise.
Build quality is advanced through the construction of an exclusive,
all-new Jaguar facility at Bridgend, South Wales. Designed using the
manufacturing expertise of parent Ford Motor Company, the Jaguar
factory-within-a-factory shares the premises of a Ford engine plant to
reduce investment. By establishing a dedicated facility, Jaguar fosters
its unique identity, which results in a high level of pride in
workmanship. The results of the Jaguar team's efforts are known
immediately--each AJ-V8 engine is hot tested before it is shipped to the
Browns Lane plant in Coventry, England, for final dress and assembly
into cars.
Engine Block with Structural Bedplate
The innovative design of the AJ-V8 begins with its most fundamental
element: the cylinder block. The die-cast aluminum block employs a
structural bedplate to establish a rigid, durable foundation for the
engine.
The bedplate is an intricate aluminum casting that forms the portion of
the block below the crankshaft centerline, incorporating the five
main-bearing caps into a single ladder-type structure. Iron liners are
cast at each main bearing position to ensure that bearing clearance
remains constant at all temperatures.
Tying the bearing caps (which support the crankshaft) together with the
bedplate results in a far stronger engine assembly for long-term
durability and less vibration.
The working surface of the cylinder bores is formed by an electroplating
process called Nikasil, applied directly to the aluminum of the engine
block -- there are no separate iron cylinder liners. The coating, just
0.003 inch thick but extremely long-wearing, is deposited by a precisely
controlled procedure in which the plating solutions are pumped through
the block in an immersion tank.
The resulting nickel/silicon carbide finish is extraordinarily smooth,
offering a number of benefits:
* Lower friction improves fuel economy and durability.
* A faster warm-up lowers emissions, improves fuel economy and
ensures that the cabin reaches a comfortable temperature quickly. Engine
warm-up is unusually quick -- about four minutes under urban driving
conditions.
* Weight is reduced by 15 pounds compared to iron liners.
* Improved oil retention reduces emissions.
Leading-Edge Technology
Like every Jaguar engine before it, the AJ-V8 incorporates a multitude
of leading-edge technologies which contribute to its broad power range,
high efficiency and overall durability.
* Crankshaft: The crankshaft is a precision casting of spheroidal
graphite (SG) iron, a material that combines light weight and optimum
crystal structure for strength and durability.
* Sinterforged connecting rods: The steel connecting rods are an
advanced design made by a technique known as sinterforging. In this
process, the connecting rod is formed in a single piece with high
dimensional accuracy. Unlike conventional rods, the bearing cap at the
crankshaft end of the rod is not cut off, but instead fracture-split in
a special fixture.
This method intentionally leaves an uneven finish at the cap-to-rod
mating surface, allowing the cap to fit back in place only one way --
with the surface irregularities interlocking. The result: The bearing
caps securely lock into the proper position and the load exerted on
connecting rod bolts is significantly reduced.
* Cylinder head: With double overhead camshafts and four valves per
cylinder, the AJ-V8 cylinder head continues a Jaguar tradition of
advanced engine design. Engineers chose the four-valve design after
testing and rejecting five-valve designs as too heavy and no more
efficient.
The efficiency of the engine is aided by a narrow included valve angle,
just 28 degrees between the intake and exhaust valves, which also
contributes to the compact dimensions of the pent-roof combustion
chamber. Additionally, these design features help give the AJ-V8
best-in-class exterior dimensions among V8 engines.
* Camshafts: The camshafts are spheroidal graphite cast iron,
rifle-drilled (through the length) to keep weight low.
* Aluminum tappets provide direct, mechanical valve actuation to
minimize noise. Thanks to steel shims at the top contact surface and
hardened cam lobe surfaces, there is no need to adjust clearances during
the life of the engine.
* Variable Cam Phasing: The AJ-V8 employs variable cam phasing (VCP)
to reap the midrange benefits of advanced cam timing and the high-speed
advantage of retarded valve closing, delivering no less than 80 percent
of peak torque between 1400 and 6400 rpm. The timing shift involves only
the opening and closing points of the intake valves; it does not change
the length of the open period (duration) or the height to which the
valve is opened (lift).
The benefit to the driver comes in crisp throttle response, with
abundant torque at low speeds and outstanding power as the engine speed
climbs toward the top of the tachometer.
The mechanical movement of the intake camshafts is performed by a
hydraulic actuator controlled by the engine management system.
At very low engine loads, as well as very low and high engine speeds,
the intake camshafts are in the retarded position. In this mode, the
valve overlap period (when both the intake and exhaust valves are open)
is a minimal five degrees of crankshaft rotation, which provides a
smooth, stable idle.
The intake camshafts move to the advanced position when the engine
operates at low-to-midrange speeds or at higher loads. In this position,
overlap increases, allowing some of the exhaust to flow into the
cylinder with the fresh mixture, benefiting emissions control. The
exhaust-laden mixture burns cooler, reducing nitrogen oxides, and
reburning the exhaust lowers hydrocarbons.
For reliability, the camshafts are driven by zero-maintenance,
single-row chains.
* Intake system: The top view of the AJ-V8 is dominated by the
curving ductwork of the air intake system, shaped to tune the length of
the intake runners for optimum midrange power.
The manifold is formed from a composite material known as Polyamide,
which has excellent insulating properties to ensure quick starting when
the engine is hot. The interior surfaces are extremely smooth to
minimize airflow disturbance.
The fuel rails, which supply gasoline to the individual injectors, are
an innovative design: They are integral with the manifold, rather than a
separate component, to ensure accurate positioning of the injectors.
* Electronic throttle: The throttle assembly is electronically
controlled rather than operated by a conventional cable or linkage. This
so-called drive-by-wire function, a technology long proven in aircraft,
offers extraordinarily smooth operation, excellent pedal feel and highly
accurate idle speed control.
A mechanical backup enables the car to be driven even if the electronics
malfunction.
* Exhaust system: Because exhaust emission levels are much higher
when an engine is cold, every effort was made to bring the catalytic
converters up to operating temperature quickly. The AJ-V8 achieves an
unusually fast converter "light off," within 30 seconds of startup.
* Cooling system: The cooling strategy of the AJ-V8 is based on a
patented, innovative split-block design, in which coolant flow is
divided 50/50 between the cylinder heads and the engine block water
jackets.
This allows the cylinder bores to operate at a relatively high
temperatures to lower hydrocarbon emissions, meanwhile keeping the
cylinder-head temperatures low to enable an unusually high compression
ratio (10.75:1) for efficient combustion. The engine warms up in less
than four minutes in the standard urban test cycle, aiding cabin
comfort, fuel economy and emission control.
* Engine management electronics: The AJ-V8 fuel injection, ignition,
emissions control and onboard diagnostic functions are all regulated by
the engine control module (ECM), a prime component of the computerized
engine management system. The various inputs (throttle position, air
temperature, etc.) and the output signals (operating instructions for
the ignition and fuel injection) are carried over the car's Controller
Area Network (CAN), which enables faster response through more rapid
data transfer -- up to one megabyte per second.
The complete engine management system is supplied by Nippondenso, a
company with considerable experience in the luxury market. Development
work was conducted around the world, from Nagoya, Japan, to Jaguar's
Whitley Engineering Centre in Coventry, England.
New Five-Speed Automatic Transmission
The XK8 is equipped with a ZF 5HP24 automatic transmission, which offers
five forward gear ratios to optimize performance. First through fourth
gears are selected for crisp response and effortless acceleration, while
fifth is an overdrive ratio to benefit fuel economy. A sophisticated
electronic control system not only ensures smooth operation, it also
makes possible a versatile shift program that adapts to specific driving
conditions.
The need for routine maintenance has even been eliminated: The
transmission fluid is installed at the factory, and it never needs to be
checked by the owner.
Development of the transmission, including the management electronics,
was a joint undertaking of Jaguar and ZF, enabling the gear ratios and
operating parameters to be tailored to the characteristics of the AJ-V8
engine.
The transmission's versatility begins with two driver-selectable shift
modes, Sport and Normal. Switching into Sport mode times the gear
changes for peak response.
The XK8 transmission also carries a self-regulating adaptive capability,
enabling it to compensate automatically for the effects of aging and to
adjust shift quality based on slippage detected in actual use. Built-in
compensation for transmission fluid temperature variations further
ensures smooth operation, even in cold weather when the fluid takes
longer to reach operating temperature.
