I am fairly confident these are original Jag Parts They have the cylinder and
bank numbers on them and are marked Rist.
The boot at the distributor is at right angles, the one at the spark plug straight.
The measurement was taken from the metal connection at the plug to a
moulding line on the distributor boot (centreline of the connector) and rounded
to the nearest 1/2 inch.

These MAY be JLM726 but I cannot be sure

If anything the measurements might be short.

1A 14.5"
2A 10"
3A 11.5"
4A 11.5"
5A 15.5"
6A 15.5"

1B 19.5"
2B 13.5"
3B 6.5"
4B 10"
5B 15.5"
6B 18.5"

I am hoping to use these in the wiring configuration noted in the Rough Idle Technical Bulliten 18-43.

I would be interested to hear if anyone has a definitive set out for their leads other than above

Coxy

 

Rist is the original supplier, yes



I may just be getting a bit dense but I don't understand the question, sorry.

"....a definitive set out..." ?

Cheers
DD

 

Sorry, to clarify.

The original post was generated by a desire to hopefully establish a correct sequence for
Re-installation of the spark plug leads for my 1985 HE.

Imagine my delight when I chance upon a Technical Bulletin outlining exactly what I was
after.

So I dutifully clean up the leads (short term fix part of a long term plan) and decided to
measure them just in case I wanted to replace them out of pre made lengths, or make my
own and thought, hell, I couldn't find this information anywhere so maybe others might be interested.

Just started to reinstall the leads to find that nothing lines up and the firing order seems to have changed!

A very kind forum member has just PM'd me to point out the Bulletin was for the Marelli distributor.

Completely forgot about the ignition change but highlights the need to be doubly sure when
Ordering online that year of the car is important.

Schoolboy error.

Coxy




A very k

 

I dont have the measurements, as I have always used Magnecore leads on the Jags, and they come numbered in the packet.

The 1A and 1B should be right angle at the sparker due to access with the "Black monster" a/c compressor.

I have also used teh right angle at the sparkers with both #6 plugs, due to room, but some have straights. #6A is a pain with a straight boot, due to the oil light switch.

 

The firing order sequence of the V12 has never changed throughout its entire life. But remember on that Lucas dizzy that the lead sequence on the dizzy goes ANTI clockwise round the cap, looking down from above. The cap will have a tiny "1" cast in the top which is where the lead for cylinder A1 goes. (the cylinder at the RHS front, ie US passenger side). Go round in the firing order anticlockwise from there.

It does not matter what the actual length of each lead is, as long as they are all correctly connected.

Greg