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).
Experimental department report summarizing development work carried out on an OHC Conversion Unit.
| Identifier | ExFiles\Box 113\5\ scan0208 | |
| Date | 13th February 1939 | |
| Detonation appears slightly worse than B.II, & a modified design of combustion chamber is suggested. R.R. 306. 5T. 50966. 6/11/37. C.E. EXPERIMENTAL DEPARTMENT REPORT REFERENCE: 1004. FILE THIS 10.2.38 COPY Subject of Report: Summary of development work carried out on OHC Conversion Unit to date. General Conclusion:- 1) Open exhaust power is some 20% better than B.II, but this is reduced to a 9% gain when standard silencing systems are fitted. Road results are only slightly better with the OHC unit than B.II probably for this reason. 3) Valve gear noises are rather bad, a improvement could probably be effected by a reduction in valve lift & increased silencing for the cams. 4) The camshaft chain drive is subject to rather severe periods, a cure being effected only by the use of two chain tensioners, a cam balancer & a camshaft flywheel. 5) The valve gear appears rather complicated, & could probably be simplified & cheapened. 6) The cylinder head joint suffers rather from leaks & requires design investigation. Copies of Report Circulated to:- Report to be noted for further action by:- Test carried out on: OHC Conversion Unit S.23. By: -- Test No. -- Date: 13.2.39 | ||