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).
The issues of noise, wear, and failure observed with a petrol pump after 7,000 miles of testing.
| Identifier | ExFiles\Box 17\5\ Scan144 | |
| Date | 20th June 1932 | |
| 87460. To E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux} Hs{Lord Ernest Hives - Chair}/GWH.{George W. Hancock - Head Chateauroux}2/MJ.20.6.32. Re. R.R. PETROL PUMP TO LEC.2961. We have run the above pump on 19-EX. for 7,000 miles. We noticed that after approx. 2,000 miles the pump became noisy at intervals, more especially when first starting up. We have taken the opportunity to examine the pump whilst the front of the engine is down. We find that a fair amount of slack has developed in the bottom of the tappet rod. The actual wear has taken place in the locating hole for the pin. We are of the opinion that the bearing arm should be increased, as although there is very little load the speed is rather high. The noise that developed was found to be due to the fabric plunger sticking in the guide. This part is being given .0075" clearance on the dia. in place of .005 as called for on the drawing. The design of the plunger is such that after grinding the top is fitted and peened over, this slightly bulges the plunger and is apt to make it stick. Another feature with the pump design is that it cannot be dismantled from the engine without pulling down the front and taking off the cam wheel. On 25-EX., which has the A.C. petrol pump fitted and which has run some 30,000 miles with no trouble, noise, or otherwise, the dismantling of the front of the engine is not necessary to dismantle the pump. The failure of the pump to deliver petrol when turned on to the reserve, as reported, was due to the non-seating of the valves. The apparent reason being due to corrosion inside the air bottles and bits of foreign matter getting under the valves. With a new head fitted we have not had the failure on reserve. Hs{Lord Ernest Hives - Chair}/G.W.Hancock. | ||