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).
Chassis IO G.III engine condition after 7826 miles.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan059 | |
| Date | 23th April 1926 | |
| To "H.S." From G.W.Hancock. Hotel de France. Chateauroux. Indre. France. Report on chassis IO G.III. after 7826 miles. ENGINE. Power. We have not noticed any deterioration in power with the performance of the car on the road. Compressions taken immediately after the finish of the run were poor, N°1.3.5&6 blew straight past piston rings into the crank chamber, N°2 was fair, N°4 had remained good. The detonations have increased. Lubrication of cylinders. The cylinders are over lubricated. They are all approx. in the same condition. Condition of cylinder walls. The condition of cylinder walls from examination without dismantling appears to be good. There are slight scores marks in N°3. Valves & fittings. We have had no trouble with valves. Tappet clearance taken when cold was as follows: N° 1 2 3 4 5 6 7 8 9 10 11 12 Clearance .003" .005" .006" .003" .005" .003" .006" .005" .004" .001" .003" .004" These have all been reset to .003". Push rods and rocker arms have given no trouble. Tappets have remained fairly quite during continuation of run, Oil still leaks from valve cover Pistons.. Pistons are fitted with "L" shape piston rings E.53625 and E.53749, otherwise to L.O.P. E.51487. We have still got a bad piston knock from N°5, when cold and hot. The tops of pistons are covered with carbon which from observation, wants decarbonising. Plugs. K.L.G. type plugs fitted. We have had no failure with plugs. | ||