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).
Issues with push rod rubbing and considerations for cylinder head modifications.
| Identifier | ExFiles\Box 10\3\ 03-page157 | |
| Date | 25th June 1938 | |
| -2- Rm{William Robotham - Chief Engineer}/Swd1.15/JH.25.6.38. ball ends. We still have push rod rubbing on the tubes and would like increased diameter of tubes to be considered. 2nd. head. As 1st. head but with 1.6 dia. inlet valves with tulip shaped head. The 1st. head will give an increase of .175 in the metal thickness between the inlet and exhaust over the present standard thickness and .125 in the 2nd. head. There is no object in moving the inlet valve towards the combustion chamber wall as from past tests the flow through the inlet valve is impaired by the baffling of the head, when this clearance is cut down. We mentioned in our earlier report Rm{William Robotham - Chief Engineer}/Swd1.4/R.26.5.38. regarding the fact that we had a venturi inlet port head, which although the metal section at the valve seats was standard, the web section above was considerably thicker. This head upon examination after 3,000 miles is warped on the inlet seats as usually found on standard heads. Rm{William Robotham - Chief Engineer}/Swd1. | ||