I copied this info from:
http://z.simplenet.com/cc/mopar/47.html
-Scott
============================================
The Upcoming 4.7 V-8
The first vehicle to receive the 4.7 will be the newly redesigned
1999 Jeep Grand Cherokee, which will carry that engine across the
world. International buyers will also have the option of a new
turbocharged Diesel engine, and both American and international
buyers can get an updated version of the 4.0 straight-six currently
in use.
The all-new 4.7-liter V-8 engine, Chrysler's first new V-8 family
since the 1960s, will have more power, less weight, increased fuel
efficiency, and lower emissions
than the LA series 318 - a member of the current youngest, and sole
remaining, V-8 family.
It will be mated with an all-new, electronically-controlled
transmission with five forward ratios. An alternate second gear ratio
will provide improved performance.
The V-8 engine will have 230-horsepower (172 kW) and 295 lb.-ft. (400
Nm) of torque, roughly comparable to the 318. It produces 30% less
pollution, noise,
vibration, and harshness. Fuel economy is 7% better (all compared with
the current 318/5.2) - with the new four-speed automatic, the engine
has more pulling power, faster initial acceleration, and three miles
per gallon better economy.
The new engine has a cast iron block and two cast aluminum cylinder
heads with a single overhead camshaft per bank and two valves per
cylinder. It displaces
4701 cm3 (287 cu in.). A relatively small bore of 3.66 inches (93 mm)
helped reduce overall length of the engine, packaging it for the
compact engine bay of the Grand Cherokee. The stroke is 3.4 inches
(86.5 mm).
Breathing features include a new tuned-length runner intake manifold,
free-flowing intake and exhaust ports and fast-burn combustion
chambers. Operating with a
high 9.3:1 compression ratio, the engine still only requires
regular-grade fuel.
Lightweight material applications and more efficient engine
accessories such as the alternator, power steering pump and air
conditioning compressor further bolster
performance and economy. Aluminum cylinder heads, a hollow camshaft
with sintered steel lobes, magnesium valve covers and a molded
composite intake manifold contribute to an overall weight reduction of
54 pounds (24 kg) compared to the previous 5.2-liter engine.
Driveability is enhanced by variable fuel injection timing,
sequential multi-port injection, a quick-sensing inlet-side
positioned thermostat and coil-on-plug ignition, in
which each individual spark plug has its own secondary ignition coil.
In order to improve fuel economy, the new engine features a patented
hybrid cooling fan system that combines in-line electric and
engine-driven fans. This system
allows the engine fan to idle at a very low speed (250-300 rpm. vs.
the typical 650-700 rpm.), decreasing noise and vibration at idle and
low speeds. The newly designed cooling system, with a high efficiency
water pump and a secondary thermostat control, reduces power
consumption by 12 percent (6 bhp/4.5 kW).
The new coil-on-plug ignition system, two-stage chain cam drive with
automatic tensioners, premium gaskets and cylinder head mounted fuel
injectors are a few of
the basic design features that provide for a greatly increased engine
life. The engine is designed to operate 150,000 miles (240,000 km)
under normal conditions without part replacement other than normal
maintenance items. A new automatic serpentine belt tensioner increases
the average accessory belt life to 100,000 miles (160,000 km).
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:08:54 EDT