Mit freundlicher Erlaubnis des Admins Serie II Club Forum, UK:
Following on from the thread a few weeks ago i promised i would compile a set of dynamic timing data for the 2 1/4 petrol engine using my Crypton engine diagnostic centre.
To start with i found our what reference data there was in the Haynes and Crypton manuals:
Haynes:
CB gap: 0.014 - 0.016". No mention of Dwell angle nor distributor type.
Centrifugal advance:
38 - 42 deg @ 4500 rpm
30 - 34 deg @ 3500
22 - 26 deg @ 2500
12 - 16 deg @ 1200
4 - 12 deg @ 900
0 - 4 deg @ 600 rpm
No advance below 450 rpm
Static timing:
8.0:1 compression TDC using 90 octane fuel, 3 deg ADTC using 85 octane.
7.0:1 compression 6 deg BTDC using 90 octane, 3 deg BTDC using 83 octane.
Crypton tune up data manual 1984 version.
Ducelier distributor, CB gap 0.14 - 0.022 Thou. Inch. Dwell angle 57 deg.
Static Timing: 8.0"1 compression TDC for 90 octane, 3 deg ATDC for 85 octane
Centrifugal advance:
38 - 42 deg @ 4500 rpm
22 - 26 deg @ 2500
12 - 16 deg @ 1200
centrifugal starts at 400 rpm
Lucas 4163 distributor, CB gap 0.014 - 0.016 Thou inch, Dwell 52 - 62 deg.
Static timing: 8.0:1 compression TDC for 90 octane, 3 deg ATDC for 85 octane
Centrifugal advance:
42 deg @ 5400 rpm !
30 - 34 deg @ 3500
4 - 12 deg @ 900
Real life measurements using my 1970 SIIa fitted with the Lucas 25 D and standard points and then the 45 D clone with points and finally the same 45 D clone with Powerspark ignition module. I do not know if mine is a 7.0:1 or 8.0:1 engine.
Lucas 25 D marked 4163.
CB gap 0.015 Thou. Dwell 59 deg @ 1000rpm
Static timing was set at 3 deg BTDC and i was using regular unleaded petrol.
Centrifugal advance:
22 deg @ 1200 rpm with vac, 20 deg no vac.
14 deg @ 900 rpm with vac, 12 deg no vac.
6 deg @ 600 rpm with vac, 3 deg no vac.
45D clone with Powerspark
This was how i was running the vehicle before i started playing around,
but i had no record of what i had set the initial static timing at
before fitting the powerspark module. When trying to find out the
static timing i used an oscilloscope and was rather confused to see the
powerspark signal was way, and i mean way after TDC, yet the vehicle ran
fine with no pinking and plenty of power.
The dwell angle with this
set up is fixed by the powerspark module and mine is just 18 deg. well
under that offered by a points set up.
Centrifugal advance:
24 deg @ 1200 rpm with vac, 14 deg no vac.
12 deg @ 900 rpm with vac, 12 deg no vac.
4 deg @ 600 rpm with vac, 4 deg no vac.
When i converted this set up back to points with a gap of 0.015 thou the static timing was shown to be TDC for this distributor.
45D with points
CB gap 0.015 thou. Dwell angle shown as 43 deg @ 1000 rpm.
Static timing TDC.
Centrifugal advance:
22 deg @ 1200 rpm with vac, 10 deg no vac.
8 deg @ 900 rpm with vac, 8 deg no vac.
2 deg @ 600 rpm with vac, 2 deg no vac.
45D with points
CB gap 0.015 thou. Dwell angle 43 deg @ 1000 rpm
Static timing 3 deg BTDC
Centrifugal advance:
26 deg @ 1200 rpm with vac, 16 deg no vac.
11 deg @ 900 rpm, with vac, 11 deg no vac.
5 deg @ 600 rpm with vac, 5 deg no vac.
45D with Powerspark module and initial static timing set to 3 BTDC using points.
Dwell = 18 Deg.
Centrifugal advance"
22 deg @ 1200 rpm with vac, 18 deg no vac
14 deg @ 900 rpm with vac, 14 deg no vac
10 deg @ 600 rpm with vac, 10 deg no vac.
When
re-checking the static timing using an oscilloscope the signal from the
powerspark module to the coil was once again way after TDC.
In terms of driving experience, starting, power delivery and smoothness of idle this is the best combination.
Conclusion
Forget trying to do anything with dynamic timing if you are just setting up a basic engine. Stick with Alan's stock answer whenever a question regarding engine timing is asked and set the static timing to 3 deg BTDC. I simply fitted points, set the gap to 0.015 thou, did not connect the CB wire back to the coil but connected it to a cheap multi meter with a continuity buzzer and the other end was put to battery earth. Then adjusted the distributor to turn the buzzer off when # 1cyl was on compression stroke and the pulley was showing 3 deg BTDC. Then i swopped out the points for the Powerspark module. You cannot expect to do static timing with the powerspark module in place.
Hope this helps.
Regards,
Nigel
Crypton Datenbuch
1966
1967
Lucas Zündzeittabelle
Lucas Zündzeittabelle für verschiedene Zündverteiler:
http://mgaguru.com/mgtech/igni…cas_distributor_specs.pdf
Und die daraus interessanten Einträge für Land Rover:
Hi,
Found this spreadsheet on Lucas distributor advance curves and additional info: http://mgaguru.com/mgtech/igni…cas_distributor_specs.pdf
There are several listed for series 2 land rovers, depending on model and year. The distributor given above, 25D4 - 41363A has listed the following:
2700rpm - 21 degs
1250rpm - 17.5 degs
450rpm - 7.5 degs
advance begins 225 rpm
4/18/12
etc
The new lucas distributor sold by Holden is 25D4 - 40944A has listed:
2700rpm - 21 degs
1250rpm - 12 degs
450rpm - 4 degs
Advance begins 225 rpm
4/18/12
etc
The IIB 2.6 litre has a 25D6 - 41227A has listed:
2500rpm - 16 degs
1000rpm - 15 degs
500rpm - 5.25 degs
Advance begins 300 rpm
4/17/6
etc
The V8 has lucas 35D8 - 41278A has listed:
2800rpm - 13 degs
1900rpm - 10 degs
700rpm - 1.5 degs
Advance begins 300 rpm
5/17/8
That's just a few lifted off the spreadsheet, if you've got the model number off the dizzy there is a good chance there is some advance curve data on there to match. There quite a few different 25D models and a few different 45D models fitted to series 2s and they seem to have different advance curves. Surprising really....
Hope that's of interest.
James
Gruß
AWo