Series 1 4.2 Litre Dynamic Timing

[tonymce]

I have just fitted 123 Electronic Ignition to my Series 1 4.2 with static timing set at 10 deg btdc. I would like to check the timing using a stroboscope but cannot find the required dynamic timing requirements. Can any of you advise?

[daverawle]

I have just fitted 123 Electronic Ignition to my Series 1 4.2 with static timing set at 10 deg btdc. I would like to check the timing using a stroboscope but cannot find the required dynamic timing requirements. Can any of you advise?

Tony, you need to know the maximum advance of your original distributor and select the first (lowest number) 123 curve that matches it. The distributor will have a five digit number with possibly a letter suffix, lookup this number in the list of Lucas distributors, you can find it here:
http://www.starchak.ca/tech/pdfs/lucas.pdf

Note that the list refers to distributor rpm and angle so you need to double it for crank data.

Dave

[tonymce]

Dave,

Thanks for your response. I have, I believe, selected the correct advance curve for the 123. My question was relating to the dynamic timing of the XK engine - I have set the new distributor at static timing of 10 deg btdc., but assume that this could be more accurately set by a stroboscopic check on the actual timing. However, I can't find any data to show what that reading should be. Can you help?

[daverawle]

Dave,

Thanks for your response. I have, I believe, selected the correct advance curve for the 123. My question was relating to the dynamic timing of the XK engine - I have set the new distributor at static timing of 10 deg btdc., but assume that this could be more accurately set by a stroboscopic check on the actual timing. However, I can't find any data to show what that reading should be. Can you help?

Tony,

The engine damper pulley should be marked and, when aligned with its adjacent pointer, indicates TDC for piston 6. Highlight the mark with white paint. If you have a dial gauge it would be worth confirming that the timing mark is correct as sometimes the damper has been replaced with one from another model, if this is the case make your own TDC mark, again with white paint. Some pictures here:
http://www.davesetype.co.uk/etype11.htm

Run the engine at tick-over with the vacuum advance disconnected and use an advance style digital timing light, triggered from plug 6, to centre the timing mark with the pointer - the readout will give you the advance. If you have the old style timing light without the advance function you will need to make a 2nd mark on the damper at 10 deg away from TDC, not so easy with it on the car.

Dave