Please check this plug

[mreid]

Take a look at this plug and tell me what you think. 427w, Edelbrock performer rpm air gap, Holley 750HP. The engine runs great, but when I look at this plug (all others are the same) with 200 miles on it, it looks a bit lean. I think I need to richen the primary jet, but wanted some other expert input first. I know the pic is a little blurry.

[bobcowan]

Unfortunately, in a modern engine it is very difficult - if not impossible - to tune the engine by reading the plugs. If it's covered with soot, it's really rich. If it's oil fouled, it's probable not firing. That sort of thing. Otherwise, you need a wide band sensor to do a really good job of tuning.

If you think it''s a bit rich, I'd leave it there. Better to be a bit (not a bunch) rich than a bit lean.

[blykins]

Can you take a picture with the flash on?

Also, if you could snag a picture of the ground strap, we can see if your timing is close....

[jhv48]

Thats how mine looked after the first few miles too. Thought I was a bit lean also. After a few more miles, they settled into a light brown color and I'm fine.

However, richer is always better than leaner when in doubt. Unless the ceramic insulator is bleached white, or has tiny blisters on it, then I would drive it a bit more and check again. But go easy on the gas pedal till your fears are eased.

[JBCOBRA]

It is fine.
Just get out there and beat it harder!

[JBCOBRA]

maybe too much anti seize
and switch to Denso Iridiums

[JBCOBRA]

Vinny said your carb needed some tuning too. You should call him

[JBCOBRA]

The groundstrap looks about right on. You could put a little more timing in it. Where is it now 32ish? and mouse grey/brown is what you want for color.

[Dwight]

try this link

it has pictures

sparkplugreading


ethanol gas does not read like the old gas we bought years ago.

Dwight

[blykins]

JB...

The part of the ground strap that shows total timing isn't visible in this picture....at least not on my monitor.

I see a mark in the radius of the strap, but it looks more like a shadow.

I do think his right rear tire is low on pressure though.

[Gaz64]

I agree with a lot of comments from others, but to me, the porcelain colouring up after 200 miles says your rich.

Don't go by porcelain colour too early, you should be looking at the outer shell and the ground strap.

The outer shell for A/F ratio, and the ground strap for timing and heat range.

Get hold of a wideband A/F ratio gauge with data logging capability, hook up the necessaries like rpm, tps, map etc.
You can do all of this even if you run carburettors.

[vector1]

i'd say looks good for a carb'd engine but you may want to read here.

Spark plug reading

[lovehamr]

Yup, that right rear tire is FUBAR..............

[mreid]

Thanks everybody. I know the picture is not the best and I'll try to get a better angle and clarity. What I am concerned about are what appear to be tiny flecks of aluminum on the insulator. In the old days that was a sign of a lean engine, but this one runs really well without the other usual lean symptoms. Could it be too much antisieze as JB suggests? My primary jet is a 68, which feels like it would be too small for this engine. I was thinking a 72 is more inline, but performance tells the story.

[blykins]

Could very well be antiseize....that stuff goes everywhere when it gets hot.

The plug doesn't look like it's been cooking to me...

[JBCOBRA]

Hi Mark
That is all it is...anti seize
A little goes a long way.
Your car runs great. I showed Vinny and it is a tad fat.
If you try the NGK or Denso Iridiums it may turn out just about perfect on the tune.