Displacemect For The Virago Eleven

While the rest of the XV bikes of the era ran a 69.2mm stroke, the eleven hundred sported 75mm. The engineers were lazy: they used the same engine dimesions and even the same connecting rods. This necessitated moving the pin bore up 2.9mm (half the stroke increase), so 1100 pistons were shorter; and due to the stroke/conrod ratio spent more time stationary at TDC and BDC. No big deal. Due to the more open combustion chamber shape, valve shrouding was considerably less of a problem, and they breathed much better. Indeed our excursions into truly big displacements will be based on 1100 (or XVS1100 - almost identical) heads and XVS1100 cranks with 920/1000/1100 rods - the V Star rods are unacceptably long, making for very short, rocking prone pistons.