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).
Test report on the B.60 chain-driven camshaft unit, detailing observations and an endurance schedule.
| Identifier | ExFiles\Box 124\1\ scan0275 | |
| Date | 30th November 1939 | |
| To Ev.{Ivan Evernden - coachwork} c. to Jnr.{Charles L. Jenner} Rm{William Robotham - Chief Engineer}/JRS.1/JH.30.11.39. B.60 Chain Driven Camshaft Unit. B.60 No.1 fitted with a chain drive to the camshaft commenced running on 14.7.39. The engine was run for a short time without the wheelcase to verify that the oil jets in the camshaft plunger were supplying oil to the chain and at the same time the movement of the chain was observed by means of the stroboscope. At speeds in the region of 2700 r.p.m. a large angular oscillatory movement of the crank and camshaft pinions was observed together with a flapping of the chain, particularly on its slack side. At first this was thought to be due to the 6th. harmonic of the torque coinciding with the natural frequency (i.e. half torsional period) but torsiograph diagrams disprove this. Torsiograph readings were taken with both the B.60 damper and the Studebaker. This is dealt with separately. The engine was fitted with 3 Vandervell three layer big end bearings and 3 R.R. standard big ends. The cylinder head was to EXS.1758 with .100 off face giving 6.9 to 1 compression ratio. Endurance was commenced on 1.8.39 to the following schedule :- Each 10 hours consisting of 7 hours at full load, 2 hours half load & 1 hour quarter load. One hour at full throttle consisted of - 15 mins. at 3000 r.p.m. 15 mins. at 3500 r.p.m. 15 mins. at 4000 r.p.m. 10 mins. at 4250 r.p.m. 5 mins. at 4500 r.p.m. | ||