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).
Re-testing of faulty ignition coils and proposing more stringent testing standards.
| Identifier | ExFiles\Box 46\3\ Scan178 | |
| Date | 12th March 1920 | |
| R.R. 63 (100 T) (S.F. 101. 23-10-18.) Bm. 4/133/s. X.3445 BY4-P12.3.20. CK{Mr Clark}, from BY.{R.W. Bailey - Chief Engineer} c.c. Mr Brock for Mr Gamble. EP{G. Eric Platford - Chief Quality Engineer} IGNITION COILS. X.3445 RE PRODUCTION TESTING OF IGNITION COILS. EP{G. Eric Platford - Chief Quality Engineer}, handed me two coils last week which he told me had given him considerable trouble on different chassis, owing to misfiring when accelerating. We carefully retested the coils and found that they, even now, fulfilled all test requirements, and that we can run them for an hour at the test speed, after which they can be dropped down to any speed, even as low as turning the distributor by hand, and never once fail during the whole of the retest. In view of the above it would appear that we require a slightly better test by increasing the spark gap. The present spark gap we are working to is 5 mm in air. EP{G. Eric Platford - Chief Quality Engineer}, considers that the coils should be capable of passing a spark across a gap of .035" under an air pressure of 64 lbs. This, however, seems to me to indicate a considerably higher resistance than the 5 mm we are at present working to. We are certain that we could pass our coils on the average against a gap of 6 mm, but I am afraid if the resistance is going to be increased above that particular point that it may mean re-considering the question of the winding of the coil, so as to obtain increased insulation. Will EP{G. Eric Platford - Chief Quality Engineer}, kindly return the two faulty coils to Mr Gamble with the cards for same, when Mr Gamble will supply him with two more tested coils to take their place. By BY.{R.W. Bailey - Chief Engineer} | ||