Plug Reading

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Mar 18, 2014 | 06:54 AM

Brcmpbl

Thread Starter

Drifting

Joined: May 2012

Posts: 1,353

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From: Calgary Alberta

Plug Reading

Pulled a few plugs for fun from the 1970. Most looked like the photo below, with a couple showing a little oil fouling, but not bad. Mostly curious about what the ones like the photo can tell me. I've looked at various websites about this stuff, etc., but sometimes a different opinion than my own is more helpful. Though you can't see the insulator and electrode well, the former is greyish or white and the latter is fine (not worn, no deposits). What does the ground strap say? It is a light grey colour to my eye.

Mar 18, 2014 | 07:07 AM

Mooser

Race Director

Joined: Apr 2011

Posts: 11,183

Likes: 3,333

From: North of Toronto - Ontario

This is one of the better charts I've come across

http://www.4secondsflat.com/plug_chart.html

Hard to say on your pic what the ceramic looks like but certainly looks good, maybe slightly on the hot side.

Mar 18, 2014 | 07:23 AM

Brcmpbl

Thread Starter

Drifting

Joined: May 2012

Posts: 1,353

Likes: 44

From: Calgary Alberta

Thanks Mooser. I thought maybe the car might be a bit on the lean side myself.

Mar 18, 2014 | 07:55 AM

bashcraft

Le Mans Master

Joined: Jan 2006

Posts: 6,501

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From: Butler Pa

Quote:

Originally Posted by Brcmpbl

Thanks Mooser. I thought maybe the car might be a bit on the lean side myself.

If it doesn't detonate, don't worry about it.

Mar 18, 2014 | 08:22 AM

Brcmpbl

Thread Starter

Drifting

Joined: May 2012

Posts: 1,353

Likes: 44

From: Calgary Alberta

I think I get a bit of detonation on the highway above 3,000 rpm if I step into it. Hard to tell though over the sound of the N11 exhaust, but somewhat confident I hear it. At idle and cruise, I can't detect any. Do get some run-on, but the 11:1 compression and pump gas might be contributing to that. I don't let it run-on though - shut it off in first with a gentle drag down with the clutch.