The 6-cylinder units shared the same 120mm cylinder stroke length, but the bore (cylinder diameter) on the larger engine was increased by 5mm to 80mm. Although a new more modern Vivastella was introduced for 1934, the earlier model continued to be listed, at an attractively lower price, in the catalogue.
The text describes two versions of a 6-cylinder engine: one with a standard bore and another with an increased bore. A newer, more advanced version was introduced in 1934, but the older model remained available for sale at a lower cost.