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).
10,000-mile report on the performance and wear of the 14.GIV engine and components.
| Identifier | ExFiles\Box 5a\2\ 02-page265 | |
| Date | 26th March 1930 | |
| To: Hs{Lord Ernest Hives - Chair} From G.W.H. Hôtel de France Châteauroux Indre 26/3/30 REPORT ON THE 14.GIV AT 10,000 MILES ENGINE UNIT IV.G.IV WITH COMPRESSION RATION 5.25 The engine started to run erratic at approx. 7,000 miles, at 7,370 miles misfires were so bad, and loss of compression was noticeable the cylinder head was dismantled to find the cause. Exhaust valves were found with a flat burnt on the face of the valve seat No 1 and 5 had to be replaced, the others were not so bad and were reground in. The engine after this attention, ran with good power and acceleration up to the 10,000 miles. EXHAUST MANIFOLD E.{Mr Elliott - Chief Engineer} 55578 The manifold was a complete failure and was replaced by one having elongated holes in the flanges sent from Derby Up to the 10,000 miles this manifold has shewn no weak features and is still O.K. the exhaust down pipe is giving a lot of trouble, the flange were it is joined to the manifold is too weak, lugs have broken off and the flange face distorted. In can be pulled into any shape by the bolts A new scheme of holding this pipe has been fitted together with a sliding joint at the silencer end. The sliding joint has completely failed owing to the exhaust pipe bending through distortion and has come right out of the joint. A sliding joint near a bend is not practicable. VALVES AND FITTINGS TO L.O.P. E.54408 NEW EXHAUST VALVES IN FIRTH CROWN STEEL E.55559 INCLUDING THE NEW E.55556/7/8. TOP WASHERS WEDGES AND CAP. REMAINING PARTS TO COMPLETE ARE EXISTING. The exhaust valves as reported elsewhere failed through there seats becoming burnt. It was noticed at the mileage of the failure, the valve clearance had become in No 1 and 5 taken up, the remaining had approx. .002" clearance left. The failure however points more to preignition than to loss of valve clearance. The valve clearance has since the failure been carefully checked each day and during 2,000 miles there has not been any loss of clearance. The setting is .004" dead cold. It increase to .006" when hot. REAR ENGINE SUSPENSION MODIFIED TO DRWG 4813 BY FITTING DISTANCE PIECE EX 4810 AND CASING EX 4809 DIABOLO RUBBERS CHAMFERED AT EACH END TO CLEAR DISTANCE PIECE. The engine mounting does not show any appreciable deterioration since our report at 5,000 miles. PISTONS E.55576-5.25 - I COMPRESSION RATIO.PISTON RINGS E.55561/2 PERFECT CIRCLE. We have not detected any knocks from the pistons during the mileage to 10,000. The momentary knock reported in the 5,000 miles report has not since been heard. Wear must have taken place on the rings as we have a much higher crankcase pressure which blows oil out of front and rear ends. This increasing with the mileage. SPRING DRIVE TO L.O.P. E 55105 The functioning of the spring drive continued up to the present mileage, there are no galloping knocks and .../... | ||