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).
Design improvements and testing for engine components including springs, rockers, and cylinder block studs.
| Identifier | ExFiles\Box 43\3\ Scan110 | |
| Date | 10th January 1927 | |
| To E.{Mr Elliott - Chief Engineer} RG.{Mr Rowledge} Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to BJ. Wor.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} R1/M10.1.27. 4003 RR. F.10, CYL. BLOCK, VALVE ROCKERS, & VALVE SPRINGS. X.3866 X.4003 X.3822 I think it would be quite good to test half gauges 136 and 098 for the 1.3 dia. spring giving stress range 28,000 and 30,000 for the inner and outer, with 54,750 max: on the understanding that lower stress can be obtained i.e. greater safety from breakage. I assume that 1.3 is an advantage in clearing rockers. I am awaiting new rocker design, rollerless, or with rollers as thought best, and equal exhaust and inlet, and to the suggestions I sent, or something better. We have not heard anything of the new type big stress range valve springs. Some of the designs submitted ( low max: ) should have been tested by now. We shall be sending the engines for their first criticisms with parts we think are not the best. A vigorous effort should be made to avoid this. I am very anxious about the joint at top of cyl. wet liner block: if so, I have little hope of real improvement unless we adopt the third and last type, which gives max: stiffness of block so that joint has more equal pressure all round. Is there permanent distortion? The breaking and tightening of the studs should not be necessary unless the block has given way, or the crankchamber, which should be watched. By all means follow up the nuts which become slack: this would finally shew what part is giving way. It would not be the steel studs. I agree to finer pitch so that stud is stronger - say 20s instead of 16, or our finest standards. It would then be to test - (1) Finer pitch. (2) Turned down studs (more or less.) (3) Spherically seated nuts. With the coarse pitch the max: stress is at a short section, and if you want elasticity it is imperative to stress the whole length approx. equally. I think you would be better with any amount of longitudinal flexibility, so as to not over-stress when hot, or have no tightness when cold. Finally there are the carbs. to alter to the type unaffected by long: inclination and acceleration. | ||