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).
Letter detailing development progress on the 'Spectre' engine, a four-bearing crank engine, and synchro-mesh gearbox issues.
| Identifier | ExFiles\Box 82\2\ scan0150 | |
| Date | 4th August 1934 | |
| H.{Arthur M. Hanbury - Head Complaints} Grylls, Esq., Hotel de France, Chateauroux, Indre, France. From Rm.{William Robotham - Chief Engineer} Handwritten: V 4553a Many thanks for your letter. Everything has more or less given place to 'SpectreCodename for Phantom III' since you left but we have managed to get the short pin crankshaft on the road. The flywheel period is non-existent and there is no roughness until you get above 4,000 revs. From 4,100 to 4,300 there is however definite roughness. Generally speaking, below 4,100 the engine is smoother than Standard over it's whole range. I want to put your disc flywheel on it now to see if that gets rid of this high speed period. The four-bearing crank engine is not going very well although the crankshaft is about finished. The casting for the crankcase has been in the shop for ten days but nobody has started to mark it up. However, now that we have a complete SpectreCodename for Phantom III chassis, other jobs will get their turn. I have the blower for it. Hall's car is not at all bad, it lapped at 99.6 without fairings on the back. The Hartfords have improved its road holding enormously. Hall seems to think that he will be able to lap at the Ulster Course at at least 75 M.P.H. with it. We have asked Hancock to arrange with you to bring the Bentley back on the 27th. after Bn.{W.O. Bentley / Mr Barrington} has tried it. The second set of parts on B.l to stop the synchro-mesh rattling were not successful. I should say they were about 50% improvement, i.e. they stopped the rattle when the box was cold but once it reached a certain temperature the rattle was as before. The springs on the plungers were about 8 lbs. We are now trying some with 16 lbs. If these are successful we shall probably try the lighter springs with an altered angle of plunger end. Attached is a blue print of what I am having made for reverse gear with a view to getting rid of all moveable parts on the lever. It seems the simplest scheme and is used on the Hornet and various other cars with complete success. Let me know how you are going to Belfast when you get back as we might go together. Rm.{William Robotham - Chief Engineer} | ||