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).
Tests conducted on Mount Ventoux, detailing issues with petrol boiling and engine starting.
| Identifier | ExFiles\Box 91\1\ scan0291 | |
| Date | 24th May 1936 | |
| Swets: noted ✓ Steadman x300a HOTEL BEDOIN ARTILLAND BEDOIN. Vaucluse. France. To. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} From. G.W.H. GWH{George W. Hancock - Head Chateauroux}/2/JAB. 24th May 1936 32. EX. Tests on Mount Ventoux. It was blowing a gale and exceedingly cold when we arrived here. A trial up the mountain found a snow blizzard raging. On Saturday morning, the weather having improved, we took 32.EX. up but could not get to the top owing to snow blocking the road, three quarters the way up. There was sufficient of the hill to carry out the necessary test for the axle. The snow had melted sufficiently during late afternoon to get to the top. The temperature was too cool to obtain temperature effects on the Bentley, therefore I decided it was useless to run this car. Re 32.EX. We have kept the bonnet conditions as you left it to obtain maximum heat under bonnet. There has been no trouble whilst climbing with water or petrol, but I am almost certain later on in the year the water would boil. During the day we climbed the mountain from the other side which has more bends and sharper. We stopped near the top leaving the engine idling. In five minutes the water was boiling clouds of steam issuing from the escape pipe. We stopped the engine and left it for 10 minutes. Upon switching on to re-start, the petrol pumps raced away and in a few seconds petrol was noticed coming from the over-flow pipe. Upon lifting the bonnet, we observed sprays of petrol from the breather pipe on top of float chamber. This was caused by the petrol boiling in the supply pipe in the vee. We then started the engine after approximately 8 attempts (see later) and for a few seconds while the engine was running, a quantity of petrol was sprayed out of the breather pipe, due as previously to the hot supply pipe in the vee. We stopped the engine and fitted the petrol pipe direct from the pump to the carburetter, clear of the vee. We again ran the engine until water boiled, then stopped for 10 minutes. Upon switching on, the petrol pump again raced away for a few seconds and again flooding occurred but approximately 50% less than first occasion, also it ceased in a few moments. We observed the breather and no spray of petrol occurred whilst standing or when the engine was started. The direct pipe is 50% better than the one in the vee, we are therefore keeping it on for the present. Re attempts to start the Engine. As stated approximately 8 attempts were made before engine finally ran. With the new petrol pipe approx. 5 (varies). Upon pressing the button the engine gives one explosion which dis-engages the starter. The next attempt starter pinion will not engage then again it is dis-engaged and so on until the engine starts up. | ||