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It is interesting to figure out what is happening at various engine speed.
The Atkinson cycle aims to maximise expansion to compression ratio.
If I understand it right, at lower throttle openings, the cylinder is already not filled up to its max because of the throttle.
At this opening, there is not gonna be a great deal of reversion because there is a throttle plate in the way and the balance between cylinder and inlet pipe is not that great.
It is also not a spot in the rpm range where Atkinson cycle is gonna improve much on Otto since most of your loss is pumping loss from the throttle plate.
When you hit peak torque, the story changes, there is air flowing backwards.
Now, what about we tune the inlet length (from valve to throttle plate) to have a spare volume fairly higher to what is gonna be dumped out of the cylinder ?
The air might have a tendency to compress before it goes back being refuelled again.
With a longer inlet we could have more "stop and go" pulses but without any issue carb wise ...
Let's not forget we want to increase static compression ratio to match the previous dynamic compression ratio to get the most out of this mod.
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