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).
The merits and integration of a Roots-type blower, comparing it to other designs and considering modifications.
| Identifier | ExFiles\Box 140\1\ scan0023 | |
| Date | 23th September 1932 | |
| - 2 - E.6/HP.23.9.32. pipe is about 1.4 to 1 by volume corresponding to 7 or 8 lbs above atmosphere. We shall be in a position to vary the degree of blower compression without unduly interfering with the shape of the delivery port if required. We have issued LeC.3196 to BY.{R.W. Bailey - Chief Engineer} for detailing. As time passes we continue to accumulate fresh information about blowers, and from what we have heard lately the Roots type of blower is capable of delivering a good boost at low and moderate speeds when properly made and is also definitely said to run quite satisfactorily without adding oil to the fuel. The Alfa is said to be a bad example of this type of blower not intended to be effective except at high speeds. We feel we cannot afford to neglect the Roots from more than one point of view and we have been going over our schemes with a view to rendering it easy to use either type at will in conjunction with the Bensport. A Roots blower with impellers having three lobes, which we rather prefer to two, can be got in to the existing layout, and we think can be carried on the engine by making a small modification to the crankchamber facing. The remaining problem is the fan drive, and we are looking into this to see if it could not be done from the blower itself. Prints LeC.3196 LeC.3216 attached. E.{Mr Elliott - Chief Engineer} | ||