Comment by chancitag
6 days ago
I recently bought a hybrid, and had been trying to wrap my brain around how it had an Atkinson engine in it. Was imagining a solenoid-driven crankshaft linkage or similar. Loved learning from this video that the secret is in valve timing and not fancy linkages.
But. The other points made felt muddled or even contradictory. I either didn't follow the TC guy's explanation closely enough, or the script could have used another pass.
Watching the graphs during the driving segment helped me more than his explanation, but maybe I'm visual about it? It's interesting to see when the battery is being used.
I've seen some modern hybrids just have a visualizer for this on the dash to encourage you to coast more and things, which seems about as helpful in understanding it too.
I'm assuming that right now all valves as computer controlled so why we cannot have best of both worlds? cannot we dynamically switch between Otto and Atkinson cycles by just changing valve profiles?
computer could use Otto cycle in case more power is needed in rare situations
> cannot we dynamically switch between Otto and Atkinson cycles by just changing valve profiles?
Toyota introduced this exact behaviour with their "Variable Valve Timing-intelligent Electric" (VVT-iE) system:
https://toyota-club.net/files/faq/16-01-01_faq_vvt_ie_eng.ht...
It uses an electric motor to control intake valve timing.
AFAIK all values are controlled by a camshaft. The computer doesn't get enough control. Solenoids seems like that are a possible replacement for CAMs, but they apparently have too many downsides.
Koenigsegg has an engine design that has a camless valve system based on their "Freevalve" technology. Its pretty cool.
https://en.wikipedia.org/wiki/Koenigsegg_TFG