BrianGar, I have read these discussions before in researching this topic. I rely a lot on the papers describing connecting rod design. I have not found anything so far, including these discussions, that describes any theoretical support for the H-beam rod except the brief mention by Charles Fayette Taylor. It would help if you could point out any particular post in the discussions you reference that you feel is definitive on the point.
I characterize the Cosworth rod and any rod by the distribution of of mass. The I-beam/H-beam separates mass into flanges connected by a thin web. Ideally, the flanges contain most of the mass and the web contains the minimum amount of mass possible. It is THIN. The H-beam rod web is a thin span running straight down the middle of the rod when viewed flat. The I-beam's web is a thin span running down the middle of the rod when viewed from the edge. The Cosworth rod has a web in two parts, under the piston pin eye and above the crank pin eye, that fits the I-beam description. There are features in the Cosworth rod and some other F1 I-beams that are H-beamish. Also, the Cosworth rod is the most solid I've seen. I already mentioned that the strongest I-beam rods have big ends that were originally more typical of H-beams. Also, the Ferrari I-beam rod has ribs along the edges of its flanges (BTW, do you think it is an H-beam?). There are more pictures of recent F1 rods out there, -ALL I-beams.
In this SAE paper by Mario Illien of Ilmore-Mercedes he makes it clear that Ilmore doesn't use H-beam rods in F1 (I think they do use them in other areas): <
Note that this paper usually costs money to see, but is free at this site. Illien does not describe the critical pistons and rods except to say that the pistons are the driver of the design and the rods are "...I rather than H...".
Illien's words are no surprise in view of Euler column theory (check out column theory for pinned columns). Also, column theory is for the static case, zero rpm. As rpms increase, additional inertial forces come into play that increase the bending moments in the plane of rotation and makes the I-beam even more preferred. The universal use of I-beams for connecting rods makes all the sense in the world... or maybe not.
The beam portion of short rods is less than 1/2 the rod's mass and the transitions from the I-beam to the pin eyes are areas of stress concentrations and differing opinions by designers. The FEA stress analysis I have seen all show the H-beam to be a more stress-free shape. I conclude that the justification for H-beam rods lies in the way the rod actually performs with respect to durability (in applications that can tolerate some extra weight) and not in column theory or strength-to-weight.
I am looking for more and especially differing analysis.