Pinnacle Engines To Present Technical Paper on Engine Efficiency Improvements at SAE 2012 World Congress

Share Article

New Internal Combustion Engine Test Indicates Efficiency Gains of 15-30%

Pinnacle Engines (SAE Booth #430), developer of ultra-efficient engine designs, will address automotive professionals at SAE 2012 World Congress & Exhibition held on April 24-26, at the Cobo Center in Detroit, Michigan. Pinnacle will share findings of a technical paper detailing how it has designed, built and tested a unique opposed-piston engine with a goal of improving real-world vehicle mileage, while avoiding additional cost. In its basic configuration, at light loads the engine obtained efficiency improvements of 15-30% over conventional poppet-valve technology.

“We’re thrilled to have developed a viable – and affordable – engine solution to significantly improve vehicle mileage without a cost penalty,” said Monty Cleeves, founder, president and CTO, Pinnacle Engines. “Due to the cleaner combustion this design allows, our engines can meet rising global emissions standards while maintaining vehicle affordability for developing nations. We are excited to bring our first engines to market in 2013 by means of a partnership with a major Asian OEM.”

Pinnacle will share expertise on the innovative spark-ignited, twin-crank, 250cc single-cylinder engine it has developed with opposed-piston architecture, using dual camshaft actuated reciprocating sleeve valves for induction and exhaust in a traditional four-stroke fashion. The presentation is significant as it details providing maximum vehicle efficiency gains at no increased cost for manufacturers and consumers.

Key results include the following:

  •     Low surface area-to-volume ratio and cool walls reduce heat loss and improve knock resistance for an efficiency improvement in the gross indicated cycle
  •     At high loads, the Pinnacle opposed-piston engine utilizes the Cleeves cycle which results from extremely delayed ignition timing and enables over-compression that does not sacrifice BMEP levels with respect to comparison engines. Though efficiency is reduced from its peak value, the enabled high geometric CR and rapid late-combustion provide sufficient effective expansion to maintain comparable full-load torque, EGTs, and efficiency
  •     A high compression ratio, unique turbulence, and spark plug layout stabilizes combustion and extends flammability limits
  •     Extended fresh-air lean operation reduces light-load PMEP, increases KLIMEP, and significantly reduces nitrous oxide emissions in the carbureted two-way catalytic markets. Improved lean combustion stability should extend to EGR operation and offer similar benefits while maintaining near stoichiometric three-way catalytic operation
  •     Results from methane operation show the potential for additional gains in efficiency as well as flex-fuel operation in the lowest complexity (fixed CR) configuration without compromise to BMEP

For more information, the comprehensive paper, “Indicated Cycle Efficiency Improvements of a 4-Stroke, High Compression Ration, S.I., Opposed-Piston, Sleeve Valve Engine Using Highly Delayed Spark Timing for Knock Mitigation,” is available for download here:

Pinnacle Engines’ Technical Paper Presentation at SAE 2012 World Congress:
Tuesday, April 24, 2012 at 10:00 a.m.
Session: High Efficiency IC Engines #PFL216

About Pinnacle Engines
Pinnacle Engines is a Silicon Valley-based technology company founded to address the immediate need for a more efficient internal combustion engine. Its founders pioneered the patented Pinnacle Engines’ architecture and its Cleeves Cycle, an ultra-efficient internal combustion engine design which leverages traditional engine manufacturing techniques. Pinnacle’s new engine design addresses the growing need to make the internal combustion engine (ICE) more efficient, and will have a significant global impact on the transportation sector’s fuel consumption and CO2 emissions. For more information visit

Share article on social media or email:

View article via:

Pdf Print

Contact Author

Tim Turpin
Visit website