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).
Proposals for reducing the weight of the Phantom engine.
| Identifier | WestWitteringFiles\N\October1925-December1925\ Scan104 | |
| Date | 21th November 1925 | |
| TO D.I. & HS.{Lord Ernest Hives - Chair} FROM E.{Mr Elliott - Chief Engineer} Copy to ~~C.J.~~ re. REDUCING WEIGHT OF PHANTOM ENGINE. With regard to the above question it is considered by Mr. Royce that the alterations for reducing the weight should be more far-reaching than merely employing a cyl. head of aluminium instead of cast iron, and as a matter of fact for a long time we have thought the weight of the crankcase itself could be considerably reduced. The first and most important point is whether we could revert to the shorter con. rods. If we used the shorter con. rods with the present pistons it would be possible to take 1 1/2" off the height of the engine if the front of the crankcase could be modified to allow this. Mr. Royce would like HS.{Lord Ernest Hives - Chair} to make experiments with an old engine having short rods to test whether we could make this alteration. The following is a list of proposals for saving the maximum amount of weight on the Phantom:- (1) Aluminium cyl. head. (2) Aluminium cyl. block. (3) Use 10" rods and present pistons, dropping top of crankcase 1 1/2". It is quite easy to go down 1" but the remaining 1/2" will mean some redesigning at the front end. (4) Shortening the engine by using thinner oval shaped crankshaft webs and modifying the cyl. bolting, also shortening central and rear main bearings. (5) Duralumin valve rockers - these would require steel ends for the rubbing faces. (6) Duralumin push rods with steel ends. (7) Lighter camshaft having larger hole drilled up centre. (8) Aluminium camshaft bearings with shorter housings in crankchamber webs. (9) Shortened oil trough for feeding oil pump drive gears. (10) Duralumin main bearing caps. (11) Reduce depth of valve tappet bosses etc. by lowering floor of valve tappet chamber, and cast large oval holes in longitudinal vertical web of chamber, also cast holes in ~~auxiliary~~ webs between intermediate cyls. in each valve tappet chamber. | ||