The engine was designed by Bert Hopwood and was a departure from Norton's previous practice of producing single-cylinder machines.

The British Government had launched an 'Export or Die' campaign to aid the economic recovery from war.

[9] The new Model 7 Dominator, using Hopwood's engine in adapted Norton ES2 cycle parts, was launched at the November 1948 Earls Court Motorcycle Show.

A shallow combustion chamber, combined with low included-angle valve configuration and flat top pistons gave a good swirl effect.

Primary drive was by chain to a wet clutch and was enclosed in a pressed steel chaincase.

[4][7][11] The Model 7 used the cycle parts of the single cylinder ES2, which used Norton's 'garden gate' plunger frame and long 'road holder' forks.

[14] (Bob Collier of Norton's experimental department had produced a prototype rigid framed model for the 1950 racing season.

)[9] The rigid model was promoted as being 2 in (51 mm) lower and 10 lb (4.5 kg) lighter than the plunger version.