Hullo Bob.......looks like the Rootes Group may have been performing the proverbial with export vehicles.......
Courtesy of Wiki........
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"The Rapier's 1390 cc engine was essentially the same as that fitted to the Hillman Minx but with a raised compression ratio (8:1 instead of 7:1), a Zenith DIF 36 carburettor and revised inlet and exhaust manifolds. In this form it developed 62.5 bhp (46.6 kW) at 5000 rpm. A column change, four speed transmission with overdrive on third and top was included in the price as a standard feature.[1]
Although the Rapier's performance was lively by the standards of its time, and its handling was considered[by whom?] to be excellent, it soon became clear[vague] that it wasn't powerful enough.[clarification needed] From October 1956, directly as a result of experience gained in international rallying by Rootes' competition department, the Rapier was fitted with the updated R67 engine on which the Stromberg carburettor was replaced by
twin Zenith 36 WIP carburettors on a new inlet manifold. This engine produced 67.5 bhp (50.3 kW) at 5000 rpm,
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I have never owned a vehicle fitted with SU carbs.........but an older cousin here in OZ owned a Sunbeam Rapier ...& my memory bank tells me it was fitted with twin SU's.......
He was always complaining
about the difficulty in the synchronization......but this is 50 years ago
.........they could have been an aftermarket installation ...........Derek