How fast is that Dodge Tomahawk (Viper engine) 500hp motorcycle able to go?
That was a publicity gig and never run over 100mph.
Large displacement car-engined motorcycles usually turn out to be disasters - the Tomahawk, for example, has a set of pretty enormous holes in the performance envelope due to physics over 100mph. Starting with the fact that it can’t turn safely at those speeds.
The Boss Hoss, a commercial product that’s basically crossing a small block Chevy engine with a Harley style chassis and running gear, is notoriously crash-prone while being slower than a modern literbike. This too has giant holes in the envelope.