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).
Test report on B.G. radio screened spark plugs for the Kestrel engine.
| Identifier | ExFiles\Box 58\2\ Scan042 | |
| Date | 1st July 1932 | |
| X1812a. X2965 Rg.{Mr Rowledge} From Hs{Lord Ernest Hives - Chair}/Yag. c. to Wor.{Arthur Wormald - General Works Manager} c. to Hy.{Tom Haldenby - Plant Engineer} c. to EP.{G. Eric Platford - Chief Quality Engineer} c. to Lp.{Mr Lappin} c. to Fl. Hs{Lord Ernest Hives - Chair}/Yag.4/MA.1.7.32. B.G. SPARK PLUGS - RADIO SCREENED TYPES. ON the homologation tests of the Kestrel engine in France, the erosion of the firing points of the B.G. type 116 spark plugs was excessive. For the further tests therefore it was decided to use B.G. radio screened spark plugs since these, embodying the screening shield as an integral part of the central electrode should run somewhat cooler than the unscreened type. Two types of plug were submitted for test. (a) The 3 CK{Mr Clark}, which has 4 earth points standing out of the body at an angle, so that the spark gap may be adjusted by closing the earth points onto the centre point. (b) The 116. This plug was exactly the same as had previously been tested except that the electrode embodied the integral screening shield. The photograph attached shews the 3 CK{Mr Clark} type, illustrating the shielding and the method of making the H.T. connection. Twelve of each type of plug were tried out in Kestrel III S 607 - 6/1 CR{Mr Cra???ster / Mr Chichester} - and the test consisted of running 5 hours at 2250 R.P.M. at 130 lbs/sq.in. M.E.P. During the whole tests the plugs functioned satisfactorily there being no signs of misfiring or pre ignition. At the end of the run the engine when tried on single ignition shewed a normal power drop. | ||