Lockheed Ventura Mk I and Mk II differences

[Graham Boak]

The Mk.Is were powered by 1850HP P&W Double Wasp S1A4-Gs, which were built to commercial standards. The Mk.IIs were powered by 2000hp R-2800-31s built to US military standards. Information from Putnam's Lockheed Aircraft since 1913, by Rene J. Francillon.

The RAF would normally change the mark numbers because of significant changes such as engines, wings, radars. They would not change them because of the armament, although sometimes (rarely) such things would be noted as series i, series ii, etc. I know of no such change to the Ventura. To be honest, it is only a few years since Tony O'Toole pointed this out on this forum, and presumably in his articles on the Ventura in modelling magazines. I'd not seen it mentioned elsewhere before then.