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).
Test report and comparison of a 12-Cylinder Packard against the Rolls-Royce Spectre.
| Identifier | ExFiles\Box 127\1\ scan0207 | |
| Date | 8th May 1935 | |
| X435 To Sg.{Arthur F. Sidgreaves - MD} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} 12-Cylinder Packard. Test by Sg.{Arthur F. Sidgreaves - MD}, C., E.{Mr Elliott - Chief Engineer}, Hs.{Lord Ernest Hives - Chair}, Cx.{Major Len W. Cox - Advertising Manager}, Bn.{W.O. Bentley / Mr Barrington}, Rm.{William Robotham - Chief Engineer} This car is fitted with a 4-bearing, 12 cylinder engine of 473 cu.ins. capacity, having a bore of 3.437". The large bore is of course a definite advantage in enabling bigger valves to be fitted. The actual engine displacement of the Packard is 473 cu.ins. compared with the SpectreCodename for Phantom III of 448 cu.ins. The tax would be, for the Packard, £56.4 per year against, for the SpectreCodename for Phantom III £50.7 " The horse power claim is 170 at 3,200 r.p.m., C/R 6.4 to 1. SpectreCodename for Phantom III is giving about 175 at 3,500 r.p.m; C/R 6 to 1. The Packard axle ratio is 4.41, against our present SpectreCodename for Phantom III ratio of 4.25. It is therefore clear that, as regards performance, since we are about 10% lighter we should be better than the Packard both for acceleration and maximum speed in spite of their bigger engine, and though there was no opportunity of side by side comparisons, we think there is no doubt that the road tests demonstrated this to be the case. From the point of view of suspension, steering, and engine smoothness we consider that the Packard was inferior to the Cadillac 16. In particular, there were two definite crankshaft periods which could be felt in the back of the car. The car was good for freedom from chunking in the drive. The slow running was no better than we can demonstrate with the present SpectreCodename for Phantom III induction system. The exhaust system was definitely more tinny under slow speed full throttle work than the system of SpectreCodename for Phantom III 1. The brakes benefitted from the vacuum servo, and the clutch was agreeably light for a similar reason. | ||