New two-stroke engine design could help keep internal combustion around longer

Re:New two-stroke engine design could help keep internal com... by LeifCarrotson on Tuesday May 26, 2020 @02:14PM (#23314528)

Still, though, series hybrids like the Volt and BMW i3 just use regular inline-4 gas engines taken from their other production lines.

The Volt has basically the same engine as in the Chevy Sonic or Cruze, and the i3 range extender option uses the same engine as their C600 series scooters. Those engines are designed with a quick throttle response and a wide power band to operate over an RPM range sufficient to drive a vehicle through a regular transmission.

I don't doubt that for the same time and money, it was far better for GM and BMW to take advantage of the economies of scale around those products than to design an engine specifically to function as a range extender, but if they really took this as a core function or started from scratch I expect they might select a medium-speed industrial diesel engine instead: something optimized for a particular speed and power output that does that one thing optimally.

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Re:New two-stroke engine design could help keep internal com... by cmrdporcupine on Tuesday May 26, 2020 @04:10PM (#23315856)

Again, completely untrue. A) Volt not a series hybrid B) the gas engine in Gen 2 Volt was not taken from their production line, it is an Atkinson Cycle engine designed for generators, not for their crappy ICE trucks and SUVs.

C'mon, can people research before opining?

"While it shares many parts with the new 1.5L I-4 used in other GM products, the Gen II engine’s combustion process and calibration are specific to the Volt. Its larger displacement not only improves fuel efficiency but also provides more torque, which contributes to the Gen II Volt’s surprising quietness."

https://www.wardsauto.com/engines/gen-ii-chevy-volt-propulsi...

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Re:New two-stroke engine design could help keep internal com... by kevin_thibedeau on Tuesday May 26, 2020 @02:37PM (#23314805)

Same physical components doesn't mean that the injection mapping wasn't customized for the constrained application.

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Re:New two-stroke engine design could help keep internal com... by LeifCarrotson on Tuesday May 26, 2020 @03:13PM (#23315272)

I hope they customized the injection mapping, but the GM LUU engine is still a naturally aspirated gas engine with 10.5:1 compression and 73.4 x 82.6 mm bore/stroke ratio, measurements which primarily came from the ICE-only target applications it was designed for.

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