Browse Publications Technical Papers 950089
1995-02-01

The Otto-Atkinson Cycle Engine-Fuel Economy and Emissions Results and Hardware Design 950089

The Otto-Atkinson cycle engine operates on the Otto cycle at full load, for good power density, and on the Atkinson cycle at part loads, for reduced fuel consumption. The Atkinson cycle has a larger expansion ratio than compression ratio. This is achieved by increasing the geometric compression ratio and employing late intake valve closing.
A modified 1.6L I-4 engine was tested with retarded, but fixed, valve timings and increased, but fixed, geometric compression ratios to simulate the Otto-Atkinson cycle. The engine demonstrated 15% improvement in BSFC relative to the standard spark-ignition engine with 10% EGR at 1500 RPM, 2.62 Bar BMEP. Tests also revealed 50% reductions in BSNOx and BSCO emissions but a 60% increase in BSHC.
A variable compression piston and a coaxial camshaft were designed and fabricated for the Otto-Atkinson cycle engine. Tests demonstrated the piston to be functional under motoring conditions, although the response was slower than required.

SAE MOBILUS

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

Access SAE MOBILUS »

Preview Document Add to Cart
Members save up to 16% 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

A Design and Experimental Study of an Otto Atkinson Cycle Engine Using Late Intake Valve Closing

910451

View Details

TECHNICAL PAPER

The Otto-Atkinson Engine - A New Concept in Automotive Economy

820352

View Details

TECHNICAL PAPER

Variable Valve Closure Timing for Load Control and the Otto Atkinson Cycle Engine

890677

View Details

X