Jack clearance measurements for Goshawk cars with deflated and inflated tyres.
| Identifier | ExFiles\Box 81\1\ scan0012 | |
| Date | 22th March 1922 | |
| X3602 Roy. {Mr H. Royce - Buyer} from Hs {Lord Ernest Hives - Chair} /TMW. JACKS FOR GOSHAWK(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) CARS. X4050 X3602 Referring to your Roy {Mr H. Royce - Buyer} /GEA2/AG10.3.22. The minimum clearance, that is with tyres deflated, is 7 1/2", this being taken at designed position for jack. Inflated, the measurement is 10 1/4". These figures are taken with a tyre pressure of 50 lbs. sq.in and 820 X 120 size of tyre. The figures for the rear axle cover the measurement for the front axle. It should be noted that with a 34" straight-sided tyre, the maximum lift to clear the ground will be at least 4" more than the figure quoted above. Hs {Lord Ernest Hives - Chair} /TMW. | ||
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).