[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Start-up Eco-Motive developing dual-fuel “H” engine; parallel, independently fueled piston banks
December 01, 2014
|The H-engine—basically two separate engines housed within the same engine block—comprises two switchable parallel piston banks, independently fueled by gasoline and CNG. Click to enlarge.|
Startup Eco-Motive has developed what it calls the first dual-fuel “H” engine; it recently received a patent (#8807098) on the design. The H-shaped engine comprises parallel left-side and right-side vertical inline piston banks, each having a crankshaft and pistons, a cylinder head, and individual fuel feeds, but sharing a common power transmission system. Each piston bank operates independently of the other but is housed within the same engine block and has separate lubrication systems.
The Eco-Motive H-motor—basically two separate engines housed within the same engine block—can be powered by either gasoline or compressed natural gas (CNG), at the driver’s decision. The chosen engine is mechanically or electrically selected via an engine bank selector box using a selector control which selects the fuel type and engages a drive gear on the crankshaft of the selected engine, and transfers power to the transmission. The selector control actuates a transfer system that prevents simultaneous operation of both engines. The vehicle stays in that fuel mode until changed by the driver.
Motiv Engines introduces 2nd-generation split-cycle concept; MkII Clarke-Brayton heavy-duty engine being designed for LNG
May 08, 2014
|Section of the MkII Clarke-Brayton split-cycle engine. Note the three different cylinder sizes. Air moves sequentially from induction (top cylinder) to combustion (middle cylinder) to expansion (bottom cylinder). Click to enlarge.|
Motiv Engines, LLC introduced the second-generation of its engine concept dubbed the MkII Clarke-Brayton Engine, which it intends to develop into a heavy-duty on-highway engine fueled by liquid natural gas (LNG). The prototype is fueled by diesel, a first step in proving the technology before developing a new LNG fuel system.
The MkII Clarke-Brayton Engine is a boxer-configuration split-cycle engine implementing what Motiv calls the Clarke-Brayton cycle. The thermodynamics of the engine are virtually identical to the company’s previous CCI (Compact Compression Ignition) design, as described in a 2013 SAE paper, but are implemented in a much more conventional way.
Dearman liquid air engine moving into performance mapping, in-vehicle trials; diesel hybrid potential
January 17, 2014
The Dearman liquid air engine—an innovative heat engine that uses liquid air (or liquid nitrogen) as a “fuel” and emits cold air as exhaust (earlier post)—completed its shakedown testing milestone at the end of 2013 at Imperial College, London, and is moving into a three-month program of tests and performance mapping.
The developer, Dearman Engine Company (DEC), confirms that the engine remains on track for integration and installation on a vehicle by MIRA (Motor Industry Research Association) in the first half of this year. The project—in partnership with MIRA, Air Products and Loughborough University and jointly funded by the consortium partners and the UK Government (IDP8)—will demonstrate and test the Dearman Engine on a refrigerated truck providing zero-emission cooling and power during 2014, before moving to full on-road field trials.