We used CSP to investigate the effect of changing helicene length on the polymorphism and intermolecular interactions for naphthalene and the [n]helicenes where n = 3 -12. We found features such as interlocked pairs with back-to-back packing are more often found in the low energy enantiopure polymorphs rather than racemic, whereas herringbone packing is more common in racemic structures. The polymorphic behaviour changes significantly with changing n, with similar packing motifs found in helicenes of similar lengths. We suggest that the grouping of similar packing types is due to the similar shapes, which we quantify using the angle between the terminal aromatic rings. This measure also loosely correlates with other global trends seen in the CSP landscapes, such as the number of polymorphs and % of enantiopure structures. A key result from the analysis of the low energy polymorphs is that the most stable polymorph of the uncharacterised [12]helicene crystal evidences a packing motif that may have high hole mobility, indicating efficient charge transport and enhanced device performance.