Loctite advice needed

[Rick F]

Over the last weekend I suffered from "three-cylinderitis" when the number one cylinder spark plug shed its spade terminal securing nut twice in a morning.

Admitedly we were doing a fair bit of low-gear work in the Lincolnshire wolds (7s to the Sea) so the vibrations were stronger and longer than usual, but it was a bit disconcerting. We finished the run with the ignition lead held in place with a bulldog clip!

I thought I had secure the second nut successfuly - tightened it down with pliers - but to no avail. Perhaps the screw thread on the plug was a bit worn?

I intend replacing the plugs and fiting new knurled nuts, but I want belt and braces, so I'm thinking of a dab of Loctite on the screw.

Can anyone recommend the grade of adhesive that will secure the nut, but enable its removal when required withot too much hassle?

Thanks in advance,

[A G Wood]

Problem is Rick, most Loctite products wont take appreciable amounts of heat (in fact heating to around 150 deg C is one easy way to release their bond).
I suspect A7 sparkplug insulators & centre electrodes will exceed that in service. I know from involuntary testing motorcycle ones certainly do...  Henkel/Loctite do make high temperature products, but that will defeat the "removal without too much hassle proviso". How about using a 4mm star type lock washer, or even these KLG pattern clips instead of nuts?

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[Duncan Grimmond]

I've found that turning the spade terminal on the lead together with the knurled nut as you tighten it down seems to add a little more grip to overcome the vibration-rattle loosening effect. ( you can also "set " all the terminals to nice parallel positions to satisfy your particularities if you're a sad git like me!)

[Malcolm Parker]

That's exactly what I do, Duncan.

[Steve kay]

And here on Spark Lead Setters Anonymous, so do I. I know we should have better things to do but being in Wales it is of course raining. So who identifies plug numbers with strips of tape on the lead, and who stamps the plug number onto the flat spade terminal?

[Chris Garner]

Moi aussi.

[Steve kay]

Chris, now I am a bit worried about what those furtive chaps peering under bonnets at Curborough were actually looking at.

[A G Wood]

... So who identifies plug numbers with strips of tape on the lead, and who stamps the plug number onto the flat spade terminal?

You may quite well laugh at the very idea,  but I acquired an unmolested HT lead conduit  for my Goodwood with a set of factory leads still in it. The rubber insulation had turned into a sticky mess aeons ago but under the grot I discovered that the spade/duckbill spark plug terminals were factory stamped with the numbers 1 to 6  

[Steve kay]

You may quite well laugh at the very idea,  but I acquired an unmolested HT lead conduit  for my Goodwood with a set of factory leads still in it. The rubber insulation had turned into a sticky mess aeons ago but under the grot I discovered that the spade/duckbill spark plug terminals were factory stamped with the numbers 1 to 6 

Certainly not laughing, taking this very seriously. Could you please illustrate the font?

[Rick F]

Thanks for all the advice.  I'd completely overlooked the heating effect. Now ordered a pack of KLG clips -  I already have a set of number stamps!!