Near as I can tell from the video, the helo had a 6 cylinder aircooled engine (looked like a flat opposed 6) with a single turbo charger attached. The rotor was a 4 blade rotor with a spider on top of the rotor shaft with pitch links going "down" to the rotor blades.
I cannot identify a piston powered helicopter with a rotor arrangment like this. The "rotor" head looks more and more to me like the tail rotor of a UH-60, which has the spider arrangement for pitch control that I believe I saw in the video. But this of course would be unrelated to the 6 cylinder aircooled piston engine (with a turbo charger) that was in the video.
(Edited for spelling error)
[ 15 December 2001: Message edited by: Flight Safety ]