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).
Engineering discussion on connecting rods, bearings, front drive design, and piston lubrication.
| Identifier | ExFiles\Box 6\6\ 06-page011 | |
| Date | 11th August 1926 | |
| (3) real objection to stepped journal diameter increasing towards the rear, we think we should follow body practice. The La{L. A. Archer} Salle costs one fifth of the 20/25. CONNECTING RODS. The general American practice is to lubricate the pistons by means of a hole drilled through the shoulder of the connecting rod. We are carrying out tests on the Bentley to ascertain the best position for this hole, and having discovered this, shall run a car thus equipped to check the oil consumption. We presume we shall be using Babbit bearings for these big ends. Manufacture is facilitated if the rod is located sideways on the steel. This is general American practice and we have a sample rod illustrating how this is done. From our experience we should expect no trouble whatsoever with a length of 1.375". At the present moment the Cadillac is running with a 2" bore and a 1" wide bearing lined with Babbit. These bearings give no trouble up to 2500 R.P.M. BEVELGEAR & BOURNE. We recommend that as soon as a scheme for the front drive is complete, we should send it over to the works until Do. of Novica to get them to pass an opinion on it. They said they would be only too pleased to do this for us. They also can supply us with one or two sets of parts for our preliminary running to ensure that English made ideas live up to the original standard. They might also like a few particulars of the constant torque to be expected. LUBRICATION SYSTEM. We suggest that if we increase the amount of oil to the pistons following American practice to ensure freedom from 'scurfing' when cold starting, the dimensions of the pump should be greater than has hitherto been our practice. The increased clearances demanded by Kelmit bearings will also call for this modification. | ||