CUMMINS TAKES THE LEAD IN DIESEL EMISSIONS TECHNOLOGY: NEW ISB ENGINE IS FIRST TO MEET EPA'S 2.5-GRAM NOx PLUS NMHC STANDARD
>Cleveland, OH - 10 Sep 2001
>
Cummins Inc. today introduced the next generation of its six-cylinder ISB 5.9-liter engine – to meet the EPA's 2.5-gram NOx and NMHC standard for 2002, ahead of schedule – at the BusCon Show in Cleveland.

The new low-emissions ISB is the latest in the Cummins proven "B" Series family of engines. More than 2 million B Series engines have been produced since its introduction.

This new higher-technology ISB will be available in July 2002 and is an excellent match for bus applications, in terms of both performance and features.

>"Cummins has designed this new B Series engine to meet the needs of our customers," said John Malina, general manager, Cummins worldwide bus business. "For the bus market, we have focused on the safety and
sociability aspects of the engine. Drivers will experience an engine that is 80
percent quieter than its predecessor, with the lowest smog-producing NOx level of
any diesel."

Cummins now leads the diesel industry in lower emissions by offering the advanced 5.9-liter engine at a standard of 2.5 grams of nitrogen oxides (NOx) plus nonmethane hydrocarbons (NMHC). Cummins has met this low-emissions standard, ahead of schedule, without using high-cost special fuel or expensive exhaust aftertreatment.

Cummins utilizes cooled Exhaust Gas Recirculation (EGR), a system
integrated into the engine design and controlled by the engine electronics. Cooled
EGR works by routing a portion of the exhaust gas through a cooler and then introducing the cooled exhaust gas into the fresh intake charge air. This mixture contains fewer oxygen atoms per volume of charge, which lowers the flame temperature during combustion, thus reducing emissions.

"Cleaner air through lower emissions is a major concern for Cummins and
for our bus customers, especially those operating in urban environments,"
Malina added. "Considering the long life of a bus, often ten or more years of operation, it's important to us that Cummins customers get the cleanest
and quietest technology available at the time of purchase," he said.

The ISB's redesigned fuel system also helps the engine meet its clean-emissions standards. This high-pressure common rail system offers a number of benefits, including:

Lower emissions – due to more precise control of injection timing and fuel quantity over a wide range of engine speeds and loads
Lower noise – with pilot injection capability for improved noise control
Improved transient response – with increased injection pressure for better performance at low-end speeds
Improved cold-weather startability – from the high-pressure fuel system
This high-pressure common rail fuel system has proven its reliability in Cummins engines in Europe since October 2000, when the Euro III version of the six-cylinder ISB engine went into production.

Higher horsepower ratings for the ISB – 230 hp and above – use Variable Geometry Turbochargers (VGT), a state-of-the-art design feature already proven in more than 40,000 engines now operating in Europe.

These VGTs are integrated into the engine's electronic controls and work
by adjusting the nozzle size, thus changing the volume of the air flow, to improve the engine's performance. They allow for optimized air handling, which improves engine response at lower speeds. Customers will notice improved performance as the engine accelerates from a stop, as well as throughout the entire operating range. In addition to performance improvements, the ISB ratings with VGTs offer Cummins customers up to a 2 percent improvement in fuel economy over the current ISB.

To reduce engine noise, Cummins has moved the gear train to the rear of
this new ISB engine. Placing the cam, fuel pump and accessory drives in the
rear of the engine, together with the new high-pressure common rail fuel
system, results in an engine that is 7 dBA quieter than its predecessor. The
reduced noise – it's 80 percent quieter to the human ear – improves safety on the vehicle and reduces driver fatigue.

While there are a number of improvements with the new ISB, Cummins has retained several proven features from its predecessor. Those include a 24-valve cylinder head, which helps optimize combustion with the proper air/fuel mixture. Additionally, the rear gear train increases accessory drive capabilities. The ISB continues to offer vertically centered injection, which helps minimize the over-spray for longer service
intervals (up to 15,000-mile oil change intervals in school bus applications).

The ISB offers horsepower ratings from 185 to 275, with torque ranging
from 420 to 660 lb-ft. These ratings are specifically designed for optimized drivetrain packages.

"With its compact size, impressive fuel economy and performance – coupled with lower emissions and noise – the advanced ISB is an excellent solution for environmentally friendly bus applications," said Malina.

Cummins, headquartered in Columbus, Ind.

The 04.5+ camshafts have a profile that is conducive to creating an in-cylinder EGR effect. They do not in any way circulate exgaust gasses back thru the intake the way a normal EGR funtions.

The cam profile is only one part of the equation, the hot side of the turbo and how it is sized, the addition of a 3rd injection event at specific times, and injection timing all need to work in unison to create the EGR effect. Remove\change one or more and the effect is drastically reduced.

Changing the cam to the early design or even a 24V profile will take away at least part of it and put the power band band down into the lower portion, but, you have to tune injection timing to take advantage of that piece. The turbo is an easy replacement and will help also at the expense of spool time.

The Cummins designed in-cylinder solution was very specific and reliant on a lot of paramters working together to make meet emissions. It worked for the power levels the trucks shipped with, like anything else it tended to cause issues when the envelope was pushed to far.

The LSA was tightened on the later cams which gives some more over lap but not enough to cause exhuast to backup into the intake. The profile moves the exhaust valve opening later in the cycle and opens it faster I believe. I don't have the specs and working from memory so its not exact.

You would have to find the cam specs at Cummins or maybe a cam make, if I ever find them again will save them.

The turbo housing is quite small on the 3rd gens which raise the drive pressure. with the 3rd event firing in there it cna spike that DP really high and just not allow the exhaust to evacuate the cylinde in the time the exhaust vlave is open. Add the late injection timing in there and thats the gist of how it works.

NOX emissions is what this setup targets and that happens under high load high rpm conditions. In reality I don't see much of anything happening until 2500 rpm's or more and at least a 50-60% load factor. At an idle there really is no EGR effect happening.

The Smarty allows to you change duration, pressure, and timing to different settings, remove TQ management, reset the speed limiter, etc. The Edge is a duration box that does a set timing curve with no adjustment.

Yes you can advance the timing back to pre-04.5 specs or even more if desired. The Smarty is much more adjustable and one is able to fine tune quite a few more things than the Edge. The beta of the Smarty SSR is supposed to have even more adjustability on high\low paramters and such.