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MG TD TF 1500 - Distributor advance curve.

Hi Guys,

I have a good friend who wants to check the advance curve on his TC which has a mildly "worked" engine. He is after data for a standard TC dizzy or the dizzy which was recommended for TF stage 3 (High comp and AEG122 cam). Does anyone know where we can get this info"? I have tried searching the Archive without success.

Bob Schapel
R L Schapel

Might be in here: http://www.ttalk.info/Tech/Advance_curves.htm Bud
Bud Krueger

Bob, check out these pages: http://mgaguru.com/mgtech/ignition/pdf/lucas_distributor_specs.pdf

Tim
TD12524
TD26711
Timothy Burchfield

Looks like there might be what you want in the book at the bottom of this----maybe

http://www.mg-cars.info/mgtd-mgtf1500-bbs/timing-2015122817381126759.htm
William Revit

According to my workshop manual the distributor for the TF stage 3 using the AEG122 cam is the Lucas D2A4/DA47/40441. This distributor is designed for the later blocks with cotter bolt clamping (cotter means wedge or tapered, so not a split pin).
For the advance curve there is a slight confusion. I did an internet search and found an undated paper from 'The Sacred Octagon', which is the magazine of the New England T Register - and the paper is attached.
However, I also have a data sheet prepared by Chip Old (deceased), who used to be the Technical Rep for the New England T Register, and I will attach the data sheet to a following posting as the system does not appear to allow two attachments.


R WILSON

Attached is the data sheet, and it gives slightly different data. The two sets of data seem to cover different rev ranges, but do not actually contradict each other. Hope they help.
(Chip Old obtained the data, with others, from Lucas Service Dept in the 1980s)



R WILSON

Thank you guys, That is exactly what we were after. It is VERY helpful! The collective knowledge in this forum is amazing. Very much appreciated.

Bob
R L Schapel

Not sure that these data are still correct for nowadays fuel.
See Manchester project.
One of the result is that timing must be more advanced. But maybe with different values depending on RPM.

Laurent.
LC Laurent31

Just FYI. The rotation for the 40162A/E DXY4A on these spec pages http://mgaguru.com/mgtech/ignition/pdf/lucas_distributor_specs.pdf is listed incorrectly. It should be CCW.

Tim
Timothy Burchfield

I think the direction of rotation is from the bottom, not the top.
R WILSON

R Wilson, why would that be? All work done on the distributor (other than complete disassembly) would be done from the top. In order to time the vehicle you would need to know the rotation from the top. additionally there is an arrow on the housing of the distributor I mentioned, clearly showing the CCW rotation. To me it's like saying a left hand threaded bolt is right hand threaded from the point of view of what it is being threaded into.

Regards

Tim
Timothy Burchfield

Tim,
It may not make any sense, but that was always the policy of Lucas, to quote the distributor rotation as viewed from the bottom. That's been the case as far back as they were making distributors. If the distributor body is marked with an arrow showing a CCW rotation, then that's another matter and you will want to assure yourself that it is usable for its intended application.
Lew Palmer

Lew, I guess Lucas was madder (crazier) than I thought. Can anyone think what the utility would be of stating the distributor rotation as seen from the bottom? Here is the stamping from the distributor on my car. According to the Lucas catalog 40162E was installed on the 51 and 52 MG TD. Just fYI, the workshop manual lists the distributor rotation as CCW.

Regards

Tim

Timothy Burchfield

Tim,
On page 21 distributer section of the Lucas Training manual, it shows an anticlockwise rotor plainly marked as turning clockwise. Mad hey.
No wonder the Lucas Heart Pacemaker did not catch on. No,I am not joking, try google.
See www.healey6.com/bulletin for the Lucas Training Manual
Ray TF 2884
Ray Lee

Tim,
On page 21 distributer section of the Lucas Training manual, it shows an anticlockwise rotor plainly marked as turning clockwise. Mad hey.
No wonder the Lucas Heart Pacemaker did not catch on. No,I am not joking, try google.
See WWW.healey6.com/bulletin for the Lucas Training Manual
Ray TF 2884
Ray Lee

Ray, thanks for the laugh (God I hope you were joking about the Lucas pacemaker). I still can't think of any reason, good or otherwise, to list the rotation of a distributor the opposite from what 99% of people working on it would need to know. I guess all TAs to TCs were LHD according to the Lucas directional formula.

Regards

Tim
Timothy Burchfield

Lucas Technical Training Course, section 3, page 14, about half way down under 'distributor rotors', it says that the direction of rotation is as viewed from the driving end. Their designers used that notation, and we just have to accept it to use their manual.
R WILSON

R Wilson, I don't disagree that Lucas considered the rotation from the gear end. I just see no logical reason for doing so. Do you?

Tim
Timothy Burchfield

Is it just another case like electric current flowing from positive to negative while the electrons drift from negative to positive?
C I Twidle

This thread was discussed between 13/04/2018 and 20/04/2018

MG TD TF 1500 index

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