The Morris Isis name was first briefly used by Morris Motors Limited on a 6-cylinder car made from 1929 until 1931. It was resurrected on a new 6-cylinder midsize car from the British Motor Corporation in the 1950s to replace the Morris Six MS.
The name was discontinued in 1958.
Morris Isis (1929–35) and Twenty Five (1933–35)
The Series I Isis was launched in March 1955 as a replacement for the Morris Six MS. It featured a 6-cylinder engine, the , C-Series unit from the Austin Westminster. Unlike the Westminster, the Isis had a single SU carburettor. The four-speed gearbox had a column change and was available with an optional Borg-Warner overdrive unit.
The car was based on the four-cylinder Morris Oxford Series II, sharing its almost-unibody shell and torsion bar front suspension. The wheelbase and front end were lengthened to accept the larger straight-six engine, and a "woody" 2-door estate version was also available. With this engine, the Isis could reach .
Unlike its sister car, the Austin Westminster, which enjoyed moderate success against the volume-selling Ford and Vauxhall sixes of the time, sales were poor, with only 8,500 sold.
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File:Morris_Isis_Series_I_side.jpg|Morris Isis Series I
File:Morris_Isis_Series_I_rear.jpg|Morris Isis Series I
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