Mopar Muscle Association UK

Hi all, been hooning around in my 360 Coronet. Motor is pretty stock with Petronix ignition, ROM Performer inlet, Eddy 600 and 340 manifolds.
Checked one of my plugs today and it was almost white. I’ve read that modern fuels make the old plug colour charts redundant, but white seems a bit lean to me. Plug is absolutely clean and is not grey.
On a possibly related point, I know Eddy 600s run leanish and at idle I get best vacuum with the idle screws in a pretty lean setting. There is a slight popping from the exhaust at idle I noted.
Car runs lovely, isles spot on and pulls through the Rev range.
But concerned about plugs being too lean.

apart from glazed, oily, melted bits or sooty, if none of them i guess all is OK, i dunno what to look for anymore

i'd be looking for a colour change on the earth strap

can't remeber exactly what causes it or why it might move, mixture or timeing or both? but on or just after the bend as you go towards the tip is about the right place, all from discussions on here in the past...

i think kev or adam were dialing in their plugs to all face the same way......

Dave

oh here we go...

https://fboignition.com/articles/sparkplugreading.html

Top Article.

Indexing spark plugs by putting washers under the plug to alter the position of the strap so it wasn’t obscuring the flame front was a thing for a while. Like many other must haves it’s been consigned to the box marked “Nah”…

I particularly liked the bit where he says based on the plug its a small block chevy, about 3 years old, and running an edelbrock carb...???!!!

Dave

I smell a whiff of showmanship!

ahaah yes but obvioulosy decicated to the cause

dave

From what I’ve read since I posted this thread it seems that the traditional approach to monitoring spark plug performance by colour has been made largely redundant due to the way new fuels burn.
That said, if it’s claggy, covered in oil and don’t fire, yer motors still knackered