[frnkeore]

As a competition engine, against other L heads, I like the 21 stud better than the large cube 24 stud applications and I like FT pistons, over domed.

With FT pistons, you can, potentially get a higher CR and totally evacuate at least 1/2 of the cylinder area, using .035-.040 piston to head clearance. With domed pistons, matching the piston dome to the combustion chamber shape, is much harder.

A asymmetric chamber shape, over the valves, sounds like it could be a great benefit but, would take a lot of development. I don't think any modern speed manufacture would invest in that, because of the low market potential.

Don't forget about the block side of the combustion chamber. Air doesn't flow very well over sharp edges and I think, rather than relieve a block, that you would be much better off, producing a radius of 3/16 - 1/4" around that side of the cylinder.

Another idea that comes to mind, is having a radius or tunnel, above each valve, with the area between them, down as close to the block as possible, say .010, trying to isolate the valves and smooth the flow, into and out of, the cylinder, as much as possible.

You don't get much cross section area (CSA) or curtain area, with a L-head so, that "tunnel" doesn't have to be to big.