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).
Technical note with a diagram discussing oil-adjusted tappets, referencing a solution from Pierce Arrow to an air-in-oil problem.
| Identifier | ExFiles\Box 173\1\ img168 | |
| Date | 22th January 1933 guessed | |
| V military or naval controlled factory. I have heard about the 1000 H.P. Allison Ethylen Glycol cooled engine but so far have no particulars. Pierce Arrow. I called in to ask them about oil adjusted tappets. Their experience has been exactly the same as ours, great greatest difficulty is in getting the air out of the oil when the latter approaches 100°C. Their tappet is just like the one Jardine sent us as far as I can see. They say the secret which finally got them clear of the oil was the bleed hole X at the top of the tappet which is only open when the valve is on its seat. This is a thing we should try i.e. our bleeds out all the time. [Diagram Text] AIR BLEED X Closed by valve when lifted AIR ESCAPE OIL AT MAIN PRESSURE SETTLING CHAMBER FOR SLUDGE CRANK CASE SPRING 20 LBS LOAD USUAL NON RETURN BALL OIL FEED | ||