Cummins to test V8 diesel with VVA
By: John Mortimer, Thursday, July 16, 2009, AutomotiveWorld.com
Variable valve actuation (VVA) remains the most challenging component technology on the road to developing a commercially viable, light duty efficient clean combustion (LDECC) diesel engine, according to Cummins.
Cummins and the US Department of Energy (DofE) have been working on a joint light duty diesel research programme that could form the basis of Cummins’ new vee engine development, of which there has been much speculation. Speaking to officials of the DofE, Cummins research and technology engineer Donald Stanton outlined on 21 May the main targets of the joint engine programme, the final 12-month stage of which (Budget Period 111) begins in October 2009.
The first aim is to improve light duty vehicle (5,000lb) fuel efficiency over the FTP cycle by 10.5% over today’s state of the art diesel engine. The second aim is to design and develop an advanced combustion system that meets Tier 2, Bin 2 NOx and PM emission standards. In addition, the engine is also required to be compatible with biofuels. For this, fuels company BP is also participating.
The 12-month engineering development programme ending November 2010 is costing US$1.6m, shared equally between Cummins and the DofE. In the programme, Cummins is developing several new combustion and emissions control strategies. According to Stanton the engine will require SCR after-treatment to achieve fuel efficiency targets that meet SFTP2 emissions compliance. He also said the engine will use closed-loop combustion control strategy.
First tests of prototype VVA systems began recently in the advanced development Budget Period 11 (January to September 2009) with funding of US$1.4m shared equally, with the second phase VVA tests due to start in the first quarter of 2010. In addition, Cummins engineers will explore the Miller cycle, as well as trapped residuals and after-treatment with thermal management. Also to be tested is a new fuelling system running at 2,200bar with seven injection events. There will also be high capacity EGR, two-stage turbocharging with a low pressure VGT, and an SCR after-treatment system.
It is rumoured Cummins will use a compact graphite iron cylinder block in production (see AutomotiveWorld.com, 7 August 2006).
According to Stanton the LDECC technology can be scaled across from the 5-litre V8 engine to Cummins’ 4.5-litre, 3.8-litre and 2.8-litre I4 engines.
Cummins has already said that it is working with Chrysler and Nissan in North America to supply new engines for use in pickups and light commercials for US and Canadian markets. This could include the Dodge Ram 1500.
A Cummins spokesperson however was coy about making public any details of the new 5-litre V8 diesel. “I cannot confirm that the V8 shown in the DofE presentation is the new engine we will be making in Columbus, Indiana for Chrysler and Nissan,” the spokesperson said: “We have not discussed the specifics of that engine publicly.”
It is understood Cummins and Chrysler are currently ‘reworking’ their manufacturing agreement as Chrysler continues to reorganise following its emergence from Chapter 11 bankruptcy and conclusion of the alliance agreement with Fiat.
The opinions expressed here are those of the author and do not necessarily reflect the positions of Automotive World Ltd.
Published on Thursday, July 16, 2009
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