[xj-s] Pre-HE distributor Specs

[Mike Morrin <mikem@southern.co.nz>]

I had the opportunity to collect some data from an old Lucas distributor
book, so I uplifted all the specs it had on 12 cylinder distributors.
Unfortunately the book predated the arrival of the HE and digital P.

I have attempted to match the info with Jaguar part numbers and models from
Jaguar Manuals, Parts books and a Lucas Spares catalogue.

Note that there are 3 families of advance spec.

Some of the matches between Lucas and Jaguar numbers involve a little
guesswork, and one of the Lucas books had a 41677 listed for the 1976 ROW,
but I think that was a misprint.  

Note that the RPM and advance degrees are referred to the distributor not
the crankshaft, and are relative to the static timing.  Vacuum is in inches
of mercury.

It would appear that 1975 cars would benefit from a bit more centrifigal
advance (as per 76-on).

Applications:

Lucas    Jaguar  Used on
P/N      P/N
--------------------------------------------------------------------
41321    C33148  E-type 71-72 (note3)
41387    C37443  E-type,XJ12 72-75 carburettor
41622    C44663  XJ12, XJ-S 75-76 fuel injected except Aus
41591    C43735  XJ12, XJ-S Australia 75- and California 76-
41592    C46173  XJ12, XJ-S Rest of world 76-
41641    DAC1380 XJ-S Rest of world from 8S11262
41642    DAC1609 XJ-S California from 8S11161, Aus from 8S11800

Lucas    vacuum vacuum vac       dist rpm
P/N      start  end    degrees   350 550   750  950 1750 2900  3500
-------------------------------------------------------------------
41321    7      13     7-9R      0   1-3.5 5.5  6-8 8-10 11-13 11.5
                                           -7.5                -13.5

Lucas    vacuum vacuum vac       dist rpm
P/N      start  end    degrees   400 600   1000 1300 2600  3500
-------------------------------------------------------------------
41387    5      8      7R        0         6-8  8-10 11-13 12-14
41591    5      8      7R        0  .5-2.5 6-8  8-10 11-13 12-14
41622    6      10     4A        0         6-8       11-13 12-14
41640    6      10     4A        0         6-8       11-13 12-14
41642    6      10     4A        0         6-8       11-13 12-14

Lucas  vacuum vacuum vac    dist rpm
P/N    start  end    deg    400 500 650 1000  1300  2400  3000  3800
-------------------------------------------------------------------
41592  6      10     4A     0   0-2 3-5 10.5  13-15 15.5  17-19 17-19
                                        -12.5       -17.5
41641  6      10     4A     0           10.5              17-19 17-19
                                        -12.5

For comparison the following data comes from the XJ-S manual HE suppliment:

Lucas    vacuum vacuum vac     dist rpm
P/N      start  end    deg     450  1000   2000      3100
-------------------------------------------------------------------
?(pre-HE) 6      10     4A     0   11-13  14.5-16.5 17-19
?(HE)     5      15     6A     0   6-8    9-11      10-12
                           
If you spot any errors, or can extend the information, please let us know.

regards,
Mike