1996-02-01

Practical Experience with Passenger Car Engine Blocks Produced in High Quality Compacted Graphite Iron 960297

Although the superior properties of compacted graphite iron (CGI) are well known, its application to the series production of complex castings such as passenger car engine blocks has been precluded by the absence of a reliable foundry production technique. Despite the narrow chemistry range over which high quality CGI is stable, recent advances in cast iron foundry process control technology now serve as the starting point for a comprehensive CGI engine development programme at Adam Opel AG.
The Opel CGI programme originated with the 2.5 litre V-6 DTM racing engine which now delivers 2.7 times more power and weighs 20% less than the standard grey iron production. Acoustical evaluations where then performed on identically designed 2.0 litre Family II engines to show that the audible noise level of the CGI engine was 1.1 to 1.5 dB(A) less than that of the grey iron engine. Simultaneously the 35% higher elastic modulus of CGI relative to conventional grey iron resulted in a 7% increase of the torsional vibration frequency. Other benefits realised from the CGI studies include a 70% reduction in bore distortion, 44% improvement in honed surface roughness (Ra) and more than 40% improvement in cylinder bore wear resistance. As a result of these positive results Opel has recently undertaken a complete redesign of its 1.4/1.6 litre Family I gasoline engine block for series production. The new CGI block is 29.4% lighter than its grey iron predecessor while providing the same power output (105 hp). The purpose of this paper is to present the results of the compacted graphite iron engine development programmes at Adam Opel AG.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Piston-Ring Coatings and Their Effect on Ring and Bore Wear

400143

View Details

TECHNICAL PAPER

New CNC-Brushing Technology for Automotive Parts Remanufacturing

2007-01-3600

View Details

JOURNAL ARTICLE

Design of an Additive Manufactured Steel Piston for a High Performance Engine: Developing of a Numerical Methodology Based on Topology Optimization Techniques

2018-01-1385

View Details

X