Honda's next-generation diesel.Honda's 2.2 i-CTD four-cylinder diesel engine already is available in Europe, but the company knows it's not clean enough to meet the EPA's Tier 2 Bin 5 emissions requirements. Adding a technology like DaimlerChrysler's BLUETEC urea injection (http://www.autofieldguide.com/articles/020705.html), is one option, but it requires that the vehicle operator replenish the urea tank. To take the operator out of the loop, Honda engineers created a NOx catalyst that generates its own ammonia to turn NOx into nitrogen. [ILLUSTRATION OMITTED] The catalyst has two layers, with the first adsorbing NOx and converting part of it into ammonia. In the second layer, ammonia is adsorbed and used to convert the remaining NOx in the exhaust into nitrogen. This catalyst sits downstream of the combined oxidation catalyst and diesel particulate filter “DPF” redirects here. For plasma focus device, see dense plasma focus. A diesel particulate filter, sometimes called a DPF, is a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine. , and features enhanced NOx reduction in the 200[degrees]C to 300[degrees]C temperature range most diesels operate within. In addition, Honda optimized the combustion chamber Combustion chamber The space at the head end of an internal combustion engine cylinder where most of the combustion takes place. See Combustion design, added a 2,000-bar common-rail injection system with piezo-electric injectors, and boosted the efficiency of the EGR EGR Engineering EGR Exhaust Gas Recirculation EGR Engineer EGR Early Growth Response EGR Extra Grace Required EGR Enhanced Gas Recovery EGR Embedded GPS Receiver EGR Emergency Generator Room system. Work remains in meeting U.S. on-board diagnostic requirements and handling fuels with varying cetane numbers, but Honda plans to have the engine available in the U.S. market by 2009. Subaru's 'Boxer' Diesel It has taken years to develop, but Subaru has finally launched its horizontally opposed four diesel engine. Subaru prefers the boxer layout as it keeps the engine's center of gravity low, its dimensions compact, and lessens driveline drive·line n. See drive train. inclination. (The latter is important with all-wheel-drive.) However, this layout also makes it more difficult to control the vibration that comes from compression ignition, which affects refinement. Use of high-pressure (2,000 bar) common-rail direct injection with multiple injections per revolution are used to quell quell tr.v. quelled, quell·ing, quells 1. To put down forcibly; suppress: Police quelled the riot. 2. the vibration while reducing the engine's NOx output. The engine also features graphite coating on the piston skirts to reduce friction, four valves per cylinder, and a single turbocharger tur·bo·charg·er n. See turbosupercharger. tur  bo·charged adj. with intercooler in·ter·cool·er n. A device for cooling a fluid between successive heating stages. in ter·cool .
[ILLUSTRATION OMITTED] by Christopher A. Sawyer EXECUTIVE EDITOR csawyer@autofieldguide.com |
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