Thanks everybody, I'm glad its being enjoyed.
Proparc,
In regard to your question about materials, there is really little comparison because the mass producers of these engines can afford far more expensive materials and processes then I can. While I can use the materials and processes, it would make it unaffordable for me to do. The alternative then is to use readily available/affordable materials and comform my designs to the processes I have available to me. For instance, the hardening of a crankshaft for me is either done by carborizing, or the use of an already tough material such as old axle shafts. Either are acceptable, but durability may not be on the scale it is with the commercially produced parts. For me that's not an issue. My engines last as long as I need them too and it I wear one out I make new parts. A well fitted engine built with common materials and no heat treating will last usually a couple seasons, then it gets rebuilt.
Thanks Currell for that compliment.