To limit exhaust emissions to less than 1 gram per brake horsepower-hour
of NOx, each G3612 engine employs a pre-combustion chamber design which facilitates burning of a lean 18:1 air/fuel mixture in the main combustion chamber.
[ILLUSTRATION OMITTED] Final Emission Standards in grams per horsepower-hour
(g/hp-h) Rated Power First Year PM NOx that Standards Apply hp < 25 2008 0.30 - 25 [less than or 2013 0.02 3.5 * equal to] hp < 75 75 [less than or 2012-2013 0.01 0.30 equal to] hp < 175 175 [less than or 2011-2013 0.01 0.30 equal to] hp <750 hp [greater than or 2011-2014 0.075 2.6/0.50 [dagger] equal to] 750 2015 0.02/0.03 ** 0.50 [dagger][dagger] * The 3.5 g/hp-h standard includes both NOx and non-methane hydrocarbons.
A rebuild kit for pre-1993 Detroit Diesel two-stroke engines gives bus operators a way to comply with the Environmental Protection Agency's urban bus retrofit program, which limits particulate matter to 0.1 gram per brake horsepower-hour
. The Johnson Matthey catalytic systems division in Wayne, Pa., offers a turbocharger and blower, along with cams, cylinder liners, pistons, and fuel injectors, as a kit to replace original components during engine rebuilding.
SwRI said the aim of its latest effort is to meet the EPA's 2010 emissions goals, with the primary objective of reducing nitrogen oxides (NOx) to 0.2 grams per horsepower-hour
(g/hp-hr) and particulates to 0.01 g/hp-hr and a secondary objective of achieving U.S.
For example, nitrogen oxide emissions have been reduced from 5.0 grams per brake horsepower-hour
, for the baseline single-injection, zero-EGR engine, to as low as 1.5 grams per brake horsepower-hour
, while particulate levels remain below 0.1 grams per brake horsepower-hour