I read Mr. Ken Cooke’s letter (The Datsun “Seven” in December issue) with great interest, and I thought it is high time now to shatter a long-standing misbelief as to the origin of the pre-war Datsuns. A lot of people, especially in England, including well-known historians seem to believe that the original Datsun of the Thirties was a copy of the Austin Seven or built under licence from Austin. It is far from the truth. If you investigate any Pre-war Datsun, even casually, you can sec at once that it has nothing to do with the Austin Seven in design. First, the engine. The original Datum of 1931 (at first called Datson but quickly changed by the time of its debut) had a 495 C.C. (54 a 54 nun.) to h.p./3,700 to 747 C.C. (56 X 76 MM.) which developed 12 h.p./3,000 r.p.m. In 1934, the engine was re-designed extensively and became the now familiar 722 C.C. (55 x 7 6 MM.) 15 h.p./3,600 r.p.m. form, which, remained in production up to 1950 with only slight modifications. These engines have a cast iron block which is integral with the deep crankcase. The crankshaft is supported by two large ball races. Con-rods are duralumium and run direct on crankpins, rather unusual design for the period. The lubrication system is quite different from Austin, too. Mains and camshaft are lubricated under pressure by a gear-pump, while cylinder wall and con-rods are splash fed by dippers and troughs in the sump. The chassis design also has virtually nothing in common with that of the Seven. The chassis frame is conventional ladder-type with channel-section side-members which extend to the full length. An underslung worm Hotchkiss drive is used and the rear axle is sprung by a pair of half-elliptic leaf springs. Front suspension is by a transverse leaf and a triangular torque arm. The front leaf spring is mounted to a very wide but thin steel plate at the nose of the chassis frame. Naturally this “cross-member” tended to flex freely (and break in use), hence these pre-War Datsun were notorious for a sheer lack of straight line stability. Brakes were Perrot-type with generous dimensions from the outset, and this could be the only feature of Datsun that excelled over the Austin! I know this only too well because I used to have a few “moments” in my own Austin Sevens!
I was rather puzzled to read in Mr. Cooke’s letter that a recent Datsun catalogue says, “Our first car manufactured in 1933 under licence”. It is of course absolute nonsense and I imagine it must have been written by an innocent English caption writer for Datsun UK. Sometimes I wish Mr. K. Gotoh had copied the Austin Seven. Then the pre-War Datsuns would have been much nicer cars!
Tokio SHOTARO KOBAYASHI
Editor, Car Graphic