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).
Issues with hydraulic dampers and the oil system, with test results for thermostats and the radiator grille.
| Identifier | ExFiles\Box 91\4\ scan0159 | |
| Date | 29th July 1935 | |
| ( 2 ) 7) HYDRAULIC DAMPERS FRONT & REAR. No ! We are not quite happy with the front dampers. I reported to you that the white metal in our dampers, shewed signs of draging and there were flakes of white metal floating in the oil. Leslie was going to take this up with you upon his return. It was suspected, that flakes had got under the Valve seats. The rear damper when examined the other day, were in a filty condition. The cast-iron was in the oil. It looked just as if grinding paste had been put in. The offside damper, the low pressure valve seating was in a bad condition. We had to regrind it. In the bellows compartment, there was dirt which had settled on the bottom. We thoroughly washed out both dampers, and reset the initial poundage of the N.S. 8) OIL SYSTEM OF ENGINE. We dont think the oil filtering or the oil system is hopeless. We say its the worst design we have ever seen or hope to. The whole of the pipe lines is a disgrace for a newly designed Engine. We have as requested, checked the flow of oil three times during the test, at the bottom and top of the main filter. Main oil pressure 14 lbs. Bottom of filter 30 lbs. Top 20 lbs. upon arrival at Châteauroux, second record; Main oil pressure 17.1/2 lbs. Bottom of filter 30 lbs. Top 20 lbs. Third test :- Main 14, Bottom of filter 30 lbs. top 20 lbs. Therefore, we have not attempted to clean it. Tests carried out to ascertain the value of the thermostats has proved interesting. The thermostats when in operation, actually give more effecient cooling at 80 MPH. We enclose figures taken with & without the Radiator Grille. The reason why the cooling is more effecient, is, in our opinion as follows :- With the thermostats fitted, there is a restriction to the quantity and flow of water through the Radiator. The cooling effect of the water passing through the Radiator is greater. This more than compensates for the increased heat absorbed by the water in the Cylinder jackets, due to the bye passing caused by the thermostats. At 60 MPH. the increased heat absorbed by the Cylinder water, just about balances out the Radiator effeciency, owing to the decreased passage of air through the Radiator. We are fitting thermometers to verify this statement. GRILLE ON & OFF. At 60 MPH. with the Cut-Away Grille, there is no difference in water temperature, with or without it fitted. At 80 MPH. it shows an increased effeciency without the Grille. This is due to the non-stream line effect of the hollow down strips of the Grille. | ||