I gotta be honest Curtis. I think your comparison to the laminar water flow in fountains is not applicable to this situation. My biggest problem is your comparison of an unconstrained external flow to a constrained internal flow. Also, I'm not entirely sure the reason your personal fountain example goes higher is due to laminar flow being 'better flowing'. I think it has more to do with the interaction of the laminar water column with the surrounding air. Essentially the laminar flowing liquid does not disintegrate because there is no internal turbulence causing water molecules to break free from the stream. This keeps the water column cohesive. From some other videos I watched, it would seem that since the water is not turbulent, the actual surface tension of the water helps keep it together as well. Since the water stream does not disintegrate, it does not disassociate in to smaller, and independent bits of water that will incur much more aerodynamic drag per unit of volume than a cohesive stream. Effectively, the more cohesive stream is more aerodynamic, and thus can go higher and/or farther. It does not mean it has more hydrodynamic head, I.E. more pressure backing it up.
As for the cylinder head discussion, I would bet lots of money that the flow exiting the combustion chamber is turbulent long before it enters the valves and exits through the ports. I would also bet that the velocity of the gas in the port is high enough to induce turbulent flow on its own. I would also assume that any laminar flow would be transformed into a turbulent flow by many of the sharp edges and turns the flow encounters on its way into the exhaust port. Namely the exhaust valves. Generally in fluid flows, a flow that has induced turbulence will remain so unless the Reynolds number falls to a very small number. And in this situation, I doubt it happens. Also, turbulent flow on it's own does not cause great pumping loses. The velocity of the gas flow is much more important. In fact, the relative roughness of a pipe in an internal flow reduces as a flow goes from laminar to turbulent. Since in a turbulent flow so much mixing occurs near the surface of the pipe, actual pipe roughness becomes much less relevant than in the case of a laminar flow where water is near the edge of the pipe for a very long time.
The thing to remember with fluid flows is that turbulent flow is not what you should be concerned about, especially in engines. You should pretty much assume you are dealing an a turbulent flow. That's okay. The thing you want to avoid is unnecessary steps, edges, contractions, and expansions. ALL of those features will cause a flow, in this case gas exiting the exhaust valves, to lose dynamic head(energy), and thus velocity. This lose of dynamic head is basically an increase in pumping resistance. By avoiding these features, you reduce your pumping resistance, and increase horsepower by allowing the exhaust gas to leave more freely.
With this in mind, I'm very skeptical about the exhaust side port work that I see. Mostly because of the exhaust manifolds that will be bolted to these heads. I'd have to measure, but it seems to me that on a 2g exhaust manifold the pathway leading away from the cylinder head decreases in cross sectional area as it approaches the collector. So it makes very little sense to me to expand the exhaust port, and expand the entrance of the exhaust manifold, only to have it decrease again. Keep in mind, that it has been a LONG time since I've seen a bare cylinder head next to an unported 2g exhaust manifold. IF there is a step between the two, it would be beneficial to remove this step. Even if the cross section area expands, and then reduces again. A smooth expansion/contract is still superior to a sharp step. Especially if it is unavoidable due to inherent geometry.