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Wedge TR8 plug reading - my read is time for head job

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Re: TR8 plug reading - my read is time for head jo

Rob,

This will either help you or confuse you even more. Please read the block explanation of the resultant pictures by the numbers. It makes more sense than some of the technical explanations, less illustrations.

https://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

See what I mean about being part art and part science? Generally, if you see what's shown on the that plugs fall within the blue numbers you'll be OK.

Now that you've done that, read on here:

https://www.centuryperformance.com/spark-plug-tech-spg-26.html
 
Re: TR8 plug reading - my read is time for head jo

Bob and Paul - great info guys. Thanks.

I think my running a colder plug might be contributing to this...
 
Re: TR8 plug reading - my read is time for head jo

tdskip said:
Bob and Paul - great info guys. Thanks.

I think my running a colder plug might be contributing to this...
Click to expand...

Ahem! :wink:
 
Re: TR8 plug reading - my read is time for head jo

Didn't we just have a conversation on reading plugs with modern fuel saying that the old school doesn't really work now?. Paul how old is that doc.?
 
Re: TR8 plug reading - my read is time for head jo

Thanks Paul - terrific stuff. Love the spark-plug mug-shots. That will help us catch our man.

So a "cold" plug will have a lower temprature at its electrode since (by its design) it is sinking more heat to the outside than a "hot" plug under the same conditions?

The problem is that if you use a cold plug in a lower-performance engine, it may not get hot enough to self-clean and so foul up. Conversly using a hot plug in a high-performance engine, and the thing might get too hot and melt!

Did I get that more or less right?

Rob.
 
Re: TR8 plug reading - my read is time for head jo

That's why I mentioned what I did about the art and science, new fuel stuff. I think that a dead rich or dead lean condition will be obvious, but if you look at the pictures from the 1977 chart, when the fuel wasn't great, but probably better than today, there is a very broad range of what is considered good.

The old school method was, smell the exhaust while running, pull the plugs, check the color, reset the timing and go rich or lean on idle mixture. Pull the next car in, please.....
 
Re: TR8 plug reading - my read is time for head jo

More or less Rob, but I've never seen a melt down from the wrong heat range alone.

Another old rule of thumb was, "Standard heat range unless you're burning oil and getting ready to trade it in".
 
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