In practice...it would indeed work!
The split cycle engine combines the intake, compression ,explosion, exhaust in one rotation of the crankshaft. In that sense it should be called a 2 cycle engine, some did, some don't.
In essence the engine looks like a 4 stroke engine with intake and exhaust valves , however one out of two pistons is used simply to compress air and the other provides the power stroke and the exhaust.
Here is a short animation from the Scuderi engineering group.http://www.youtube.com/watch?v=Kogz4wed ... re=related
The Scuderi group calls this engine a 4 cycle. In fact Scuderi who claim the invention makes little mention if any of the original inventor of a similar engine, Dugald Clerk (a Scott) who around 1880 patented a two cylinder engine doing exactly the same thing (with some minor differences). The Clerk engine was then refered to as a 2 cycle engine and was designed to compete with the Nicholaus Otto's newly invented 4 cycle type that we know. http://www.rider-and-road.com/Timelines/Era1.htm#1878
Clerk Two Cycle Engine
The merit of the Clerk design is that the engine was actually producing one power stroke per rotation, I too prefer to call it a 2 stroke engine. Dugald Clerk engine's gas-air intake was achieved through a conventional venturi and the compression stroke compressed a mixture, not just air as can be done today with direct injection.
I do believe that such a 2 stroke cycle is a superior design. Like other 2 stroke engines the torque and bhp per crank rotation would be far superior than that of 4 cycle engines . Unlike other 2 cycle engines the Clerk cycle engine would not suffer from conventional 2 cycle engines downsides: oil burning, port to cyclinder rings damage, unpredictable crankcase lubrication (in downhilling for instance) and longevity.
For the seven this type of engine could produce a high output/low weight and high rpm rates and yet could be built using mostly existing production engine components such as engine blocs, pistons, connecting rods, direct injection, flywheels, starters etc . As an illustration a 4 cylinder block could be used rebuilt, the crankshaft would have to be altered (or a new one machined) to make pistons work synchronised in pairs ; one pair at 180 deg from the other one. The cylinder head or maybe just the camshafts would have to be redesigned and I have not thought of it yet.
These are preliminary thoughts obviously. The Scuderi patent barrage should expire within three years. I think that ordinary 2.0L 4 cyclinder engines converted the Clerk way to 2 cycles could become 1.0 L displacement engines and possibly produce around 250 hp/liter, just like the 1. 0 L V4 regular 2 stroke race thing that was discussed last year on this forum.
I will be glad to discuss this idea with you if you are interested.