RC51 engine vs Superhawk Engine
 

So heated discussion today with one of my riding buddies. Are the superhawk and RC51 running the same engine block with different internals? Or are they two completely different motors?

I believe they are totally different engines:
VTR: 98 by 66, RC: 100 by 63.5 (if I remember corrrectly)
VTR: chain-driven cams, RC: gears
etc....

They share a 90 degree spread and basic architecture (DOHC, 4 valve heads) but I think that's about it.

The first two are RC, the second are the VTR

http://en.wikipedia.org/wiki/Honda_VTR1000F

In 2000 Honda produced the RVT1000R (RC51) known outside the United States as the VTR1000SP, though the bike had only four engine parts in common with the SuperHawk.

http://www.motorcycle.com/mo/mchonda/rc51.html

Only the countershaft sprocket, valve tappet shims and valve seals are the same; everything else is new.

Different block; the exhaust headers don't match up (interchange).

Totally different. The list goes on and on and I don't have all night so I'll end this with " In my opinion they are different". Thank you.