You're probably more well aware of the intricacies than I am, but I don't know that I'd be looking too
closely at the Model A engine for design inspiration. http://www.modelaengine.com/
Only for the water jacket, as the A has easy access to that part of the design.
So which way did you ultimately end up going with the overall head layout and design, or are you still not 100% certain yet?
It's a 90 degree V engine, initially a V-twin or V4, depending on if I can get two more liners. Head layout will be overhead valve, I think I have that nailed down in how to do it. The rods will be a Fork and Blade connecting rod. Huron head design, to keep it simple. I am keeping the stroke low, and the rods long, to reduce side-stresses and improve performance. The head flow was designed by my friend around his racing engines porting, which gives them a lot of breathing room. Two valve per engine, due to the needs of the casting method being used. Any more would be too complex. As it is now, will be pushing the limits of my small foundry's abilities.
I have to say your updates keep me coming up with crazy ideas of building an engine someday too...Of course then I either decide there's already something too similar already available, or even for all of its unique glory can't justify the expense for something that will likely never perform (horsepower, torque, fuel economy, emissions, reliability, or longevity) anywhere near as well as most any of the previously mentioned production engines in addition to probably costing an order of magnitude more when all is said and done.
IKWYM, but at the same time, there's that inner voice going "You can do it your own way" and then suddenly I feel like putting on some Sinatra...
Aren't you in the Seattle area, or nearby? If you ever want to grab a beer and talk engines or whatnot, shoot me a PM
Just north of it in Lynnwood, and sure.