821 Hyper 4V bore 88mm stroke 67.5mm 848 Testa evo bore 94mm stroke 61.2mm Longest stroke Ducati have used on a 4valve. Will have small valves so be economical, long stroke so should be grunty, also explains 110bhp compared to 848 140. 851. bore 92mm stroke 64mm.
It's interesting as the 88mm bore seems to be a favourite with Ducati in 2V form - 696 (696cc @ 57.2 stroke), 750 (748cc @ 61.5 stroke) and 796/800 (803cc @ 66mm stroke). I'm wondering if this 4V is using up some of those 2V pistons to consolidate the bores that Ducati are using and keep costs down.... (yes, I do have a spreadsheet of all the bore x stroke with capacities and the bikes marked!)
Will be like a stroked 748. Complete turn around on previous 15 years development of shorter strokes and bigger pistons.
