Plug leads & cross arcing

winkle · Post by **winkle** » Fri Jun 27, 2008 6:04 pm

Maybe this has been raised before, but Ive seen loads of pictures of V8 engines (often competition or modified) with the plug leads cable tied in pairs. ie; touching each other. Im well aware that according to many people there can be a problem with cross arcing, hence plug wire separators.

i'm curious to know; are plug leads better quality now so cross arcing isnt a problem or is tying them together still a no no?

Steve

stevieturbo · Post by **stevieturbo** » Fri Jun 27, 2008 7:51 pm

Ive seen leads routed and bunched in some extremely bad ways, on some very fast cars.

So either modern leads are very good....or all the talk about cross arcing or firing, is nonsense.

mgbv8 · Post by **mgbv8** » Fri Jun 27, 2008 9:38 pm

My Mallory and Magnecor leads can be touched together and they dont short out.

ChrisJC · Post by **ChrisJC** » Sat Jun 28, 2008 6:41 pm

If the leads were prone to arcing in any way, then dirty or damp leads would give a misfire.

I think with modern leads, it really doesn't matter. The leads just work properly.

Chris.

winkle · Post by **winkle** » Sun Jun 29, 2008 1:09 pm

Cheers guys, its not that important cos I could use separaters but I think they look neater if tied in pairs.
Ive just bought some MSD helicore leads and with the instructions it says they must be separated particularly with cylinders 5&7 because they fire in sequence, if cross arcing occurs one of them can run lean causing damage!? But as I have seen, and you have said it never seems to be a problem.

CastleMGBV8 · Post by **CastleMGBV8** » Sun Jun 29, 2008 2:15 pm

Steve,

Sounds like your making progress, I remember having a missfire problem with my 3500S which I bought new back in 1973, it went back to the dealers several times and they never completely cured it, it was obviously caused by the arcing between 5 & 7 a combination of poor quality leads and not seperating the 5 & 7 leads in the holders. but of course I didn't, and neither did the dealer know that at the time and we didn't have the benefit of the internet and boards like this one to help with problems.

Kevin