I was curious about the horsepower and how it fairs to other S65 racing engines. I don't if this is an apple and oranges comparison. I don't know much about this subject but I like hearing about all that is going on.
Anyway, this article reads "his BMW S65 V8 should crank out between 560-570 hp and the rpm range runs up through 8,600-8,700 rpm."
http://www.enginebuildermag.com/2017...s65-v8-engine/
And KMS' video shows 6xx HP (maybe the dyno is different etc).
Of course we have the regular guys on this forum building engines as well and might even play a part in the background with your builder (you never know).