Dennis Palatov really likes the Hayabusa V8, of course, it's hard not to. Dennis, though, has the experience of building the DP1, a carbon fiber bodied track day car with a Hartley Enterprises Hayabusa V8 for power. Being the kind of guy he is, one is never enough so the next thing you know, Dennis takes delivery of an Ariel Atom, the minimal, tube framed open wheel roadster and found the grin factor pretty high, but after looking at the engine compartment he started wondering if it "shoulda had a V8." Tape measure in hand and SolidWorks on the computer and next thing you know, the 4 cylinder engine is gone and the V8 is installed.
Of course, it's a bit more involved than that and Dennis has the complete build story on his web site but he sent a note to let me know the Ariel Atom has been driven under power for the first time. The little V8 fits in there like it was designed for it. The engine is about the same size as many 4 cylinder engines but weighs only 200 pounds. Specs for the engine from the Hartley web site are 2.8 Liters (170 cu. in.), 4 cams, 32 valves, 400HP @ 10,000 rpm with stock street cams and 245 ft-lbs torque @ 7500 rpm. Weight of the Ariel Atom, 1200 pounds which yields expected sub 3 second 0-60 and top speed of 160 mph+. Yes, that should be fun.
Dennis keeps really detailed records of his builds on his web site and if you find big power in small packages interesting, you need to get over there and check it out.