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).
Tests to cure air intake roar on a Phantom II using a de-tuner with a semi-expanding carburetter.
| Identifier | ExFiles\Box 13\4\ 04-page064 | |
| Date | 14th October 1932 | |
| Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from G.H. Whyman. C. to Hs{Lord Ernest Hives - Chair}/Ltd. C. hs{Lord Ernest Hives - Chair}/32/14/10 Tests to cure Air Intake Roar on Phantom II. with Semi Expanding Carburetter fitted. The first tests were carried out on 22-EX. This was undoubtedly the worst "Roarer" of any of our Phantom II cars, the worst period being from 57 - 63 m.p.h. on top gear. We rigged up a special de-tuning apparatus to find out the size of de-tuning chamber required to cure this particular bad period of roar. SKETCH OF DE-TUNER A - Air intake pipe. B - De-tuning chamber. C - Adjustable plunger to vary size of B. 1, 2 & 3 - Appertures in A to carry B when blank caps removed. BLANK CAPS. To Carb. | ||