 This engine featured a highly powered supercharger, which was a critical element enabling the engine to deliver the required performance in order to attain the envisioned altitude performance.The supercharger's installation, the detail work of which having been performed by Clifford Tinson, was a two-stage system; the first-stage compressor was permanently engaged, but the second-stage incorporated clutches which enabled it to be manually engaged by the pilot upon attaining the correct height.This arrangement was necessary to avoid administering an excessively dense mixture to the cylinders when flown at low altitudes.