From: Steve & Jeanne Keith (cckw@attbi.com)
Date: Tue Jun 03 2003 - 04:01:39 PDT
NAVISTAR UNVEILS CAMLESS DIESEL; 1ST TO POWER 2003 FORDS.(Navistar
International Corp.)(Brief Article)(Statistical Data Included)
Author/s: Lindsay Brooke
Issue: May, 2000
The engine's new hydraulically actuated G2.8SV injectors will be sourced
from a new U.S. joint venture with Siemens AG. The digital actuators, shown
here atop the valves, were developed by Navistar in a joint venture with the
Colorado-based Sturman Engine Systems.
Navistar International Corp. recently took the wraps off one of the auto
industry's most anticipated products: an engine whose valve-train is
operated electronically, without a camshaft.
In development since 1995, the so-called "camless" design will replace all
of Navistar's light-duty on-highway diesels, including those powering Ford
pickups, vans and SUVs. They'll enter production beginning in 2003 and ramp
up in volume through 2007 -- the year the new federal Tier 2 emissions
regulations begin for most light trucks.
The camless engines, including a modular V-6/V-8 family for Ford and an
inline six for International trucks, are Navistar's technical solution for
meeting the ultra-strict emissions laws, which critics say will be a
challenge for diesels.
"We had to make a paradigm shift away from the mechanical world, to achieve
the new emissions regs cost effectively," Patrick Charbonneau, Navistar
vice-president of engine engineering, tells AI "We will be camless across
all of our product lines by 2007."
Rather than open and close its valves with conventional camshaft, pushrods
or cam chain, lifters, rocker arms and valve springs, the camless engine
employs an electro-hydraulic actuator mounted above the valves. It
eliminates 140 parts, compared with a conventional diesel. On larger diesels
it also eliminates the separate compression brake -- a $1,000 to $1,500
savings per engine.
The digitally-controlled system is an out-growth of Navistar's
electro-hydraulic, low-pressure common rail fuel injection, notes
Charbonneau. It provides continuous, independent variable valve timing, lift
and speed, which helps boost power, improve combustion and reduce engine-out
emissions.
Controlling an engine's valvetrain electronically "opens the door for other
future systems aimed at boosting efficiency and power," explains Dan Ustian,
president of Navistar's engine group, "including cylinder deactivation and
variable compression ratios."
The camless engines will feature advanced after treatment systems being
developed by Degussa, Englehard and Johnson Matthey. They are designed to be
operated on ultra-low-sulfur (less than 5 parts per million) diesel fuel,
which Charbonneau and other engine experts expect will be available
nationwide in a few years. Navistar claims that NOx emissions will be
reduced by up to 70%, with significant gains in fuel economy. Particulate
emissions are claimed to be reduced to 90% below the EPA's proposed 2010
diesel regulations.
And the engines are quiet and virtually odorless, as witnessed by Al at
Navistar's technical center near Chicago.
The first of the camless engines in production will be a new 4.5L V-6. It is
slated for the 2003 Ford F-Series trucks, E-Series vans, Expedition and
Excursion. To be built in a new, $250-million plant in Huntsville, Ala., the
V-6 "will have performance equal to a diesel V-8, with 20% better fuel
economy, a 35% manufacturing cost advantage and 70% lower NOx emissions,"
promises Charbonneau. "It will enable us to enter the under 8,500-pound
light-truck market, including SUVs, in high volume." A 3.5L version will
appear in 2005.
The new 6.0L camless V-8 shares 90% of the V-6's parts and replaces the 7.3L
V-8 now used in many Ford light trucks. The 6.0L will produce more than 300
hp and 500 lb-ft of torque.
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