Been there,done that and I doubt the hp figure very much,mine was only 1010cc but had plenty of goodies - balanced crank,massive cam,head work,webbers,extractors etc and only produced 48kw at the wheels.I believe that converts to about 80 bhp,it did spin to somewhere around 10,000 rpm though,sadly it would barely last 2 rallies before stretching rod bolts and chewing out crank bearings.They were never gonna be a 1 litre grunter with 3 main bottom ends,do the big hp motorbike engines have the same?? anyone???
Al.