HT Lead separation

[Ben Hutchings]

How important do you reckon keeping HT leads separated is? I’m using some little plastic organiser clip things but in some places it’s almost impossible to stop them touching. 

Any thoughts? The reason I ask is I have pretty lumpy running at the moment due to a dodgy coil I think (awaiting spare funds to replace) but I’m also checking everything else in the ignition system at the same time.

[Beans]

With good quality wires (which you have) it shouldn't be a problem. My cars are running with closely organised HT leads. And so far never had any problems. The leads for cylinders #3 and #4 on the DHC are touching over about an inch  

[Ben Hutchings]

Ok thanks Theo. I wondered if there might be some induction issues even if no actual tracking, but guess Magnecors are suitably insulated 😁

[piman]

Hello Ben,

 

this is an interesting subject and one that would need some special test equipment to see if there is some voltage induced in adjacent leads (Which there must be, but it is the amount and effect that is unknown). As the 'slave' lead (for lack of a better description) cannot fire due to it being out of time there won't be any obvious effects. It could  be loading the main lead such that it is robbed of some power possibly? If you have some extra or old leads so that you can route the cables so they are not close (i.e. use long leads where short ones are) you can do a practical test. Where leads cross at 90 degrees does not matter, it's only on a parallel section will you get induced voltage.

For what it's worth Smokey Yunick, in America (Look him up if you don't know the name) did some trials on this and made sure there was a relatively large distance between ignition leads on his stock cars.

 

Alec