20 HP marker usage for those using the right-angle plug D50946/7/8 distributor connection.

  E51071-6, Bush (Ignition Wires), 1 ea, at the distributor, style P.

  E17793-8, Wire Bush, 1 ea, at the spark plugs, style Gp.

  E18449, Chater Lea spark plug terminals as used on the late Ghosts are called for on all of the 20's.

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The ignition wiring drawings for the first 1000 cars are discussed on the Early 20HP page. The LOP and GA numbered E53204 cover all 20HP starting with #1001: series E onward. Because of inconsistencies between the GA and LOP's our opinion, subject to revision, is that the wire marker usage for cars #401-1000 is better described by the drawings for series E. Both E53204 drawings are located on the RROC, 20HP disc under the Wire Fittings and Ignition Wiring headings respectively. These are now titled for 20HP, not the earlier project code name of Goshawk. E53204LOP is applicable from 20's numbered 1001 to 6700. At first reading this is confusing since there were only about 2956 20's built. Further study indicates that the later series listed on the LOP are actually those for the 20/25 cars. Using RROC numbers, the total production of 20 and 20/25 models was 6780. It seems obvious that this drawing titled simply for 20HP is actually applicable to the later 20's and ALL of the 20/25's.

The only wire marker notes on LOP E53204* apply to a change made during the 20/25 production. Note J (right hand side) on page 1 of the LOP reads: "1 off ea required up to the end of 'U' series". The LOP on page 1 calls for 2 each of 6, E51071-6 (style P), markers subject to note J. Since E51070 is absent, there was no style Z marker on the coil wire and the material called out for these style P is 'synthetic' insted of the earilier 'Bakelite'. The previously used Bakelite is a 'synthetic' material so this may, or may not be a change of materials compared to the style P usage on the later Ghosts. (See our Materials page.) Page 2 of the LOP* calls for 1 each of 6, E17793-8 (Style Gp), markers subject to the note: "M - Not used after 'U' series". Taken together, this information tells us that there was one set each of styles Gp and P used through the U series, and 2 sets of P afterwards. Since the 'U' series were 20/25's, all of the 20HP range from 1001 to the end continued using one set each of the two late Ghost style markers Gp and P.

These notes and revisions tell us the LOP was updated by erasing the original quantity of 1 for the E51071-6 markers and entering quantity 2 with a note J, etc. Or possibly the entire drawing was re-drawn; since the drawing is undated and unsigned we cannot tell which might have been done. Either way, this demonstrates an effort to keep the drawings updated and accurate although that goal seems to have not always been achieved.