How does this spark plug look? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 07-24-2010, 01:22 PM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Help reading this spark plug?

After 2 WOT runs. The silver line on the insulator is where I cut too shalow the first time. The black smudges is where I touched it with my greasy hands
thanks


    Advertisement

Last edited by kyle86; 07-24-2010 at 03:12 PM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 07-24-2010, 02:30 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
Last time I had a plug like that, the timing was way too far advanced and I was getting detonation.

On the other hand, it could be very, very lean.

From what I understand, a water leak into the combustion chamber can also do that, but I think too far advanced timing is the most likely cause.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-24-2010, 03:10 PM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Cause of what? I cut that plug open with a hack saw. I thought it looked on the rich side since the fuel ring is so high up.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 07-24-2010, 03:17 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Nova Scotia, Canada
Posts: 337
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
The cause of it being pure white. Advanced timing can make an old crusty plug look bone white again.

I didn't see that you only did two runs with it though. Maybe just ignore me.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-24-2010, 03:24 PM
Registered User
 
Last photo:
Join Date: Jul 2010
Location: New Jersey
Posts: 620
Wiki Edits: 0

Thanks: 8
Thanked 7 Times in 6 Posts
From my experience it looks a tad lean to me, I like a hint of tan/sandy color to mine to be safe...Was the plug removed right as you finished the WOT runs? Or did you drive around cruising for a bit afterwards?

I always check my plugs at the track right as I enter the return road, I pull over and pull one asap, thats the most accurate way to read em.

What kind of carb?What Jets?what weather conditions? also how high compression on your motor?

On a side note, Why did you cut them opened to read em? You dont have to do that..
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-24-2010, 03:31 PM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Dajerseyrat
From my experience it looks a tad lean to me, I like a hint of tan/sandy color to mine to be safe...Was the plug removed right as you finished the WOT runs? Or did you drive around cruising for a bit afterwards?

I always check my plugs at the track right as I enter the return road, I pull over and pull one asap, thats the most accurate way to read em.

What kind of carb?What Jets?what weather conditions? also how high compression on your motor?

On a side note, Why did you cut them opened to read em? You dont have to do that..
Ran down the strip, went back to the pits and then pulled some out.

Holley carb 750 vs, 76/80 jets, humid 86 degrees, 10:1 compression or slightly under.

I cut them open so I could see the fuel ring down in there. I tried with a magnifyling glass and flashlight with no luck. I don't have an ottoscope.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-24-2010, 03:37 PM
Registered User
 
Last photo:
Join Date: Jul 2010
Location: New Jersey
Posts: 620
Wiki Edits: 0

Thanks: 8
Thanked 7 Times in 6 Posts
Quote:
Originally Posted by kyle86
Ran down the strip, went back to the pits and then pulled some out.

Holley carb 750 vs, 76/80 jets, humid 86 degrees, 10:1 compression or slightly under.

I cut them open so I could see the fuel ring down in there. I tried with a magnifyling glass and flashlight with no luck. I don't have an ottoscope.
Same comp as mine, same size carb,same jetting as mine..In 78 to 80 degree weather My plugs had a bit more tanish to them..I would make the secondaries .82 and do another pass if you pick up MPH your going in the right direction, pull it and see..Lean is mean, but Im more conservative, cause if it dropps to the low 70's youll run even leaner..

Try the .82's should look a slight bit more tan..(thats how I like it anyhow)If it dont slow you down, run with the slightly richer jetting, to be on the safe side.

Fronts, leave em alone..Do some street cruising with no WOT runs, and then pull the plug after driving for 20 minutes..Dont let it idle to much, just drive 2500-3500 rpms..

Should look nice and tan.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-24-2010, 08:48 PM
Registered User
 
Join Date: Dec 2004
Location: San Jose Ca
Age: 62
Posts: 472
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Reading spark plugs is like a science.I spent a lot of time on a dyno many years ago.Either go to a dyno or change jets and read mph.Anything else is asking for trouble.On a 1600 vw we dynoed the operator killed the motor on a load and we checked the plugs, they looked lean to all of us .The dyno operator was quiet,so I asked him. He said he couldn't read spark plugs but by the bsfc numbers it was rich so we leaned it out and over the process picked up 12 hp.Plugs always looked lean
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 07-25-2010, 12:07 AM
4 Jaw Chuck's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Mar 2002
Location: Manitoba, Canada
Age: 46
Posts: 4,950
Wiki Edits: 0

Thanks: 2
Thanked 87 Times in 71 Posts
That plug looks slightly rich to me, not bad though and might be OK for power if the temps were high that day and you want a jetting that works for colder weather (under 60F).

I don't use rings on the insulator for checking jetting, the fuel today doesn't color them well like they did in the old days. Use the ground electrode instead, the tip should be blue and the carbon on it should be gone almost to the shell. Using that criteria that plug looks rich to me, unless your running race fuel of course.

Drop two sizes and post a pic again.
__________________
Outlawed tunes from outlawed pipes
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 07-25-2010, 02:16 AM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 9,222
Wiki Edits: 0

Thanks: 26
Thanked 422 Times in 386 Posts
Looks pretty decent to me, heat range looks right, we prefer the heat line on the strap to be right at the bend, so you look fine to me. Like has been said, jet up and keep watching the mph.

If you keep jetting up and it goes faster, and you go more than 4 steps up in the front(or rear), .. and you street drive the car you can trade some of that fuel over to the power valve channel restrictions(PVCR), enlarge them and go back to leaner main jetting for economy. Get the best of both worlds that way.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 07-25-2010, 02:31 AM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 4 Jaw Chuck
That plug looks slightly rich to me, not bad though and might be OK for power if the temps were high that day and you want a jetting that works for colder weather (under 60F).

I don't use rings on the insulator for checking jetting, the fuel today doesn't color them well like they did in the old days. Use the ground electrode instead, the tip should be blue and the carbon on it should be gone almost to the shell. Using that criteria that plug looks rich to me, unless your running race fuel of course.

Drop two sizes and post a pic again.
Thanks for the info! I will post an update after I drop a couple rear jet sizes. I have to order them from summit since I'm missing 78s.

Just curious, when you're looking on the ground strap, how do you defrentiate between fuel and the heat range? I know I can run a 1 step hotter plug and it will take the color past the bend. I'm a newb at spark pug reading so I'm trying to get the technique down. Thanks!
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 07-25-2010, 02:36 AM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by ericnova72
Looks pretty decent to me, heat range looks right, we prefer the heat line on the strap to be right at the bend, so you look fine to me. Like has been said, jet up and keep watching the mph.

If you keep jetting up and it goes faster, and you go more than 4 steps up in the front(or rear), .. and you street drive the car you can trade some of that fuel over to the power valve channel restrictions(PVCR), enlarge them and go back to leaner main jetting for economy. Get the best of both worlds that way.
Sweet, thanks! I guess I should try going up some, and down some and see how it responds.

Yea I've heard about drilling out the PCVRs. That's one thing I eventually want to try when I get the WOT tune down. I'm kinda nervous since it's irreversible, but metering blocks are cheap anyways.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 07-25-2010, 03:58 AM
ericnova72's Avatar
More for Less Racer
 
Join Date: Jan 2007
Location: S.W. Lower Michigan
Age: 47
Posts: 9,222
Wiki Edits: 0

Thanks: 26
Thanked 422 Times in 386 Posts
Drill and tap the PVCR's to 6-32 thread so it will accept screw-in restrictions. You can either get them predrilled, or buy blanks and drill your own.
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 07-25-2010, 09:41 AM
Registered User
 
Last photo:
Join Date: Jul 2010
Location: New Jersey
Posts: 620
Wiki Edits: 0

Thanks: 8
Thanked 7 Times in 6 Posts
See how the difference in opinions on the color of the plug vary...I would invest in a nice Widband O2 sensor like a Innovate brand, or AEM...These will allow you to bring a laptop to the track and log the pass in real time, then go back and look at the data of the A/F..

I personally like my pump gas N/A cars in the 12.5-13.0 range for power and safety..
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 07-25-2010, 11:47 AM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by ericnova72
Drill and tap the PVCR's to 6-32 thread so it will accept screw-in restrictions. You can either get them predrilled, or buy blanks and drill your own.
Is there a link you can post of these? I am very interested in them.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
changing plugs?on a V10 ford?how!? bonzipenguins Engine 23 06-03-2009 06:29 PM
Ignition system info................ poncho62 Electrical 18 10-11-2008 10:10 PM
Spark Plug brands question Francis Engine 65 07-15-2008 12:01 AM
spark plug getting little spark 72 chevy elcamino Electrical 1 10-19-2003 04:54 PM
Weird spark plug situation?? Jim Weeks Engine 4 05-13-2002 07:32 PM


All times are GMT -6. The time now is 04:12 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.