'Racing has played a major part in the development of all Aston Martin engines since Frank Halford designed the original 1.5-litre unit for Bamford & Martin. The 3,995cc 6-cylinder light alloy engine fitted to the DB5 is in all major respects the same as that which powered the 4-litre prototype which ran in the 1962 and 1963 Le Mans 24-Hour races.' Autocar, 21st May 1965.
Aston Martin's post-war evolution took a giant step forward with the launch of the DB4 in 1958. The engine was still an all-alloy, twin-overhead-camshaft, six but the old W O Bentley supervised 3.0-litre unit had been superseded by a new design by Tadek Marek. The new 3,670cc engine featured 'square' bore and stroke dimensions of 92mm, and developed its maximum power of 240bhp at 5,500rpm.
Enlarged to 4.0 litres by means of a wider (96mm) bore, a revised version of the Aston Martin six first appeared in the Lagonda Rapide, and in 1963 was standardised on the DB4's replacement: the DB5. On the standard arrangement of triple SU carburettors, this 3,995cc engine produced 282bhp, while from September 1964 the 314bhp, triple-Weber Vantage version became available.
The serial number suggests this engine left the factory fitted to a DB5 and was in fact previously installed in the DB5 from the Collection (lot 312), although it is not the original engine for that car. Current condition is unknown but understood to be operational when removed.