No Connecting Rods!
 

Opposed (Conjoined) piston engine with no connecting rods

I always liked the Scuderi Split Cycle engine but I thought it should be a boxer. What's popular with the cool kids these days in three cylinder/six piston opposed engines.

So maybe an opposed piston split cycle engine?

Here is a four cylinder version. A flat eight?

Conjoined Piston Engine with Eccentric Connecting Rods

It appears the stroke is ~.68 the bore in this instantiation.

no connecting rods
 

If they can achieve a BSFC of 0.135 lbs / bhp, and zero carbon, they'll win all the marbles.:)

Youtube also recommended this video to me. I thought it was interesting.

Compare the Achates Power solution. Two crankshafts, one combustion chamber vs one crankshaft, two combustion chambers.

I do wonder how much friction or how quickly those gear mechanisms will wear. Seems like a lot of force with very little movement distance.

Seems quite unpractical. Any increase to stroke would also be dependent on an increase to the bore too.

Even though the Achates Power design requires conrods and two crankshafts, it doesn't require a valvetrain which adds complexity. Not to mention the Achates Power doesn't require head gaskets, and the absence of actual cylinder heads is also claimed to decrease thermal losses.

Thanks. I think that's what I was looking for.

Is it just me, or does anybody else sees some resemblance of its crankshaft with the one of a Wankel?

Not sure why this is us in the unicorn gallery. I don't see any ridiculous claims being made, but it seems like a novel and compact arrangement.