Ok, so I solved an issue while making a mistake. Silly me!
I created another linkage in MotionGen that fulfilled all the requirements from the previous devlog:

• The pistons don’t overlap
• The areas connecting the linkages don’t overlap

Unfortunately, in focusing on this, I forgot a crucial requirement: that the displacer crankshaft should be 90 degrees ahead of the power crankshaft. I had done it the opposite way. Instead, I set it up so that the power piston’s crankshaft was actually 90 degrees ahead.

By that time I had already modeled a prototype in Onshape and started CADing the final. But oh well, I should fix my mistakes anytime.

So! I have redesigned the linkage in MotionGen and it should fulfull all the requirements and have no mistakes (my peanut brain is bound to make one more though :’) ).

I hope to create a working prototype in Onshape to finally build and test it.