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).
Cylinder re-boring intervals and related maintenance for Bentley cars based on mileage and usage.
| Identifier | ExFiles\Box 103\2\ scan0096 | |
| Date | 25th March 1938 | |
| W/K - GWH.{George W. Hancock - Head Chateauroux} BY.9/N.25.3.38. Re: Bentley Cylinders. Referring to our discussion on the question of cylinder re-bore, before replying to 'C', I asked the Repair Dept. for their views, and they have now informed me that their experience has shown that it is usually possible to run 30,000 miles without disturbing the Pistons. Their recommendations are at the present time for two top de-carbs at 10,000 and 20,000 miles and a bottom de-carb. at 30,000. They point out however there are occasional exceptions, due to the conditions of running, and these have been found in the past to be cases where an owner uses the car for short journeys. You may remember I though Wengers, might be a case of this nature, and I should like to know if you can find out, just what type of running this owner does. As against this we have Raymond Mays car, with 40,000 miles before a re-bore and Mr Beeby who did 79,000 before a re-bore both being known hard drivers. The Repair Dept. also state, according to records of Kingsbury re-bores during the last month, the average mileage was 37,000, the lowest being 19,500 and the highest 50,500. It is evident however, that we do get cases of re-bore being necessary round about 19,000 - 25,000 miles, and it is these I am particularly interested in, and should like as much information on as possible, such as (a) when the car was delivered, (b) mileage, (c) conditions under which the car is used. BY.{R.W. Bailey - Chief Engineer} [STAMP: MAR 25 1938] | ||