This information was taken from rallycars.com, found this while I was looking in to engine geometry

"The YB series of Cosworth engines are "super square", short stroke i.e. bore is greater than stroke (90,8 x 77,0 mm in this case) thus advantaging high rev output rather than low end torque as is the case in long stroke engines. It's a fact that all Cosworth engines, even heavily modified ones, require to be operated in relatively high revs in order to be responsive"

And this taken from Iskycams

"Lengthening of valve timing in the gasoline engine brought on accidental overlapping of the intake and exhaust valve events. (Both intake and exhaust valves are slightly open at T.D.C.
In the early days, this unintentional overlapping was at first considered detrimental. But much later, it was discovered that a mild scavenging effect was obtained from the overlap event when the exhaust actually pulled some of the intake charge in"

Adjusting how the cams over lap cam make a huge difference to how the car drives, this is a quote from J1mbo in a thread I was asking about engine stroking

"My own engine spent a week on the dyno playing with cams and I could vary torque from 450 to 490lbft of torque just with timing
I settled at 470lbft and 552bhp as 2wd I didn't want too aggresive and wanted a wide power band"

If you want any of the links to read the full articles I'll happily find and post them