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).
Exhaust manifold failures and the condition of a stripped engine, specifically a seized camshaft bearing.
| Identifier | ExFiles\Box 109\4\ scan0107 | |
| Date | 29th June 1939 | |
| -7- Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell}2/MH.{M. Huckerby}29.6.39. EXHAUST MANIFOLDS. We have always had trouble with exhaust manifold failure on the test beds, but the B.80 and B.60 fail much quicker than any previous unit. There are several ways we could experiment to improve this feature. Taking the eight cylinder separated manifolds, (a) Breakages occur on manifold section either side of the fixed, (non slotted flange) at this point to have generous radius between the branch and the main pipe with increased metal section. (b) Have the fixed flanges next to the downtakes Nos. 4 and 5 as against the present Nos. 3 and 6. (c) Whether Foundry can without undue cost increase, alter the analysis of the iron to be more resistant to cracking. The sections of the failed manifolds are very uneven and we have one failed manifold which is .125 section on one side of the bore and .250 on the other. (Photograph attached). CONDITION OF STRIP. The rear camshaft bearing (Vandervell Babbit) was badly scored and very similar to the front bearing which siezed after running the engine for only 20 minutes. It is unaccountable as on eight previous engines similarly fitted, we have had not the slightest trouble. One feature which may have some bearing on the trouble is that from the outside housing surface of the bearing some digging in had taken place. In view of this, the crankcase details should show a radius on the entrance edge for the bearings to be pressed into position. According to the makers this is very important. Other than one big end bearing which had local score grooves, the remainder of the engine was in good condition. Rm{William Robotham - Chief Engineer}/Swdl.{Len H. Swindell} | ||