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).
Investigation into the cause and remedy for a petrol smell in a Wraith body.
| Identifier | ExFiles\Box 10\2\ 02-page39 | |
| Date | 8th December 1937 | |
| To By.{R.W. Bailey - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} 651 Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}6/JH.8.12.37. Following complaints of the smell of petrol in the Wraith body we have found that with a full tank, petrol builds up to the level of the filler cap and escapes through the vent hole in the washer on a right hand corner. At the same time the air vent connection on the filler head is held on by a stud lock washer and nut. This allows petrol to escape inside the body and accounts for the smell. To prevent the loss of petrol we have fitted 28.0.V1. with a small diameter (3/16") copper pipe connected to the filler head and across the top of the tank to the offside then down and clear of the body, and at the same time fitted a washer with no vent. On the skid pan with a full tank no quantity of petrol escaped either on a right or left hand corner and only a table spoon full was collected at the end of the pipe after a fast run of 120 miles starting with a full tank. The smell of petrol was still apparent in the body with the above arrangement. We have since modified the existing air vent by using a solid washer and cap nut instead of the plain nut and lock washer on 27.0.V1. This car is now free from the smell of petrol although petrol is still lost down the wing, no modification having been carried out to prevent this. We suggest that this simple alteration be made to existing drawings and on the six cars now building. The additional vent pipe prevents the loss of petrol but would add expense and the quantity now lost could be reduced by halving the size of vent hole and making sure this was always placed at the top of the washer. In any case loss of petrol only takes place with a full tank and hard driving on corners. Owing to the relatively lower position on Bentley Ill we shall probably be forced to adopt this type of venting. Rm{William Robotham - Chief Engineer}/J.B.Dixon. | ||