Help Me Read These Spark Plugs
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
Help Me Read These Spark Plugs
The pics are Autolite 103's I had in my cam only LS3. I used them in my old high compression LS1 build but I think they're too cold for this setup (they're same as TR6's) I switched to Champion Copper 408's which are stock heat range plugs for an LS3. So do the plugs look too cold for you guys as well? The plugs were on the car about 1500 miles since I put the motor together. Ive since adjusted the timing (less of it, 28* wot) and fuel, 12.8-13.0afr wot. I don't drive long distances and I think the cooler weather as well made it worse, cold plugs couldn't burn off all the carbon.
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
Some info,
LS3, stock block and heads
TSP 231/236 114lsa
LS1 coils with Taylor 8.5mm LS3 plug wires
I was seeing 28* timing at wot so I know the ecu wasnt pulling any timing and I didnt see any knock retard either. No blowby, doesnt use oil and oil looks clean. Plugs were dry also when I pulled them.
LS3, stock block and heads
TSP 231/236 114lsa
LS1 coils with Taylor 8.5mm LS3 plug wires
I was seeing 28* timing at wot so I know the ecu wasnt pulling any timing and I didnt see any knock retard either. No blowby, doesnt use oil and oil looks clean. Plugs were dry also when I pulled them.
Melting Slicks
Joined: Jun 2012
Posts: 3,163
Likes: 6
From: Oceanside California
The carbon may be from too cold of plugs, but as for the orange burnt areas of the porcelain, are you running any additives allot? Adding octane booster etc? From what I understand, that color can come from too much additives.
Monitor you new plugs though and maybe it will just have been a heat range issue. I'm sure you plan to do that anyway.
Monitor you new plugs though and maybe it will just have been a heat range issue. I'm sure you plan to do that anyway.
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
Likes: 137
From: SoCal CA
Yeah, once it put some miles on the new plugs Ill check them out. I havent ran any additives but the car still had some e85 fuel in it when I first put the motor in it. I did use an octane booster once when I first ran it at the track. Not sure if that would do it. Ive done more tuning since then.
Safety Car
Joined: Aug 2011
Posts: 4,450
Likes: 410
From: Portland OR
Octane booster gave them the orange hue. Very common for octane boosters due to the MMT addative. Nuke nailed it.
BTW....about all octane boosters do is turn the plugs orange.
Plugs in my car look pretty bone white after and I drove it all summer and put nearly 50 dragstrip runs on it to boot.
The carbon on the base of the shell is normal.
Ron
BTW....about all octane boosters do is turn the plugs orange.
Plugs in my car look pretty bone white after and I drove it all summer and put nearly 50 dragstrip runs on it to boot.
The carbon on the base of the shell is normal.
Ron
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
Thnx Ron. I only used the booster cuz the tune had a lil too much timing at first and i wanted to avoid knock. Last time i use that stuff.
I was wondering if I was right about it looking like it was too cold of a plug. Just wanna make sure since all plugs looked the same.
I was wondering if I was right about it looking like it was too cold of a plug. Just wanna make sure since all plugs looked the same.
Safety Car
Joined: Aug 2011
Posts: 4,450
Likes: 410
From: Portland OR
We have all tried the booster! That orange simply won't burn off.
I don't think you can make a real good determination about heat range from those plugs. In fact, for just driving around (not racing or going WOT all the time) heat range isn't real critical.
I'd put a new set in and run em for awhile and have a look. That's why I bought the NGK TR5 and TR6 plugs, cheap to play with.
Others may have a different view.
Do you log with HPT or EFI live? Shows detonation right away.......
Ron
I don't think you can make a real good determination about heat range from those plugs. In fact, for just driving around (not racing or going WOT all the time) heat range isn't real critical.
I'd put a new set in and run em for awhile and have a look. That's why I bought the NGK TR5 and TR6 plugs, cheap to play with.
Others may have a different view.
Do you log with HPT or EFI live? Shows detonation right away.......
Ron
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Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
I have a data logger app and I used my friends hptuners. It showed a lil knock once in a while when it was warm at first. That was the old tune from my 12:1cr ls1 with a big cam and i used the same type of plugs. I lowered the timing and adjusted the afr. I havent seen knock but on cold starts the idle would be a lil rough for a sec. I pulled the plugs and they were all that dark brown orange color. The 103's are on the cold side so I figured that for a basically stock motor with a mild cam I would be ok with stock heat range, especially now that the weather is cooler.
Thread Starter
Safety Car
Joined: Apr 2007
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From: SoCal CA
With new plugs the car started and idled very nicely right off the bat. The booster i tried was a few months ago already, like august. I wouldve thought it wouldve burned off but that stuff bakes on hard.
Cruising
Joined: Oct 2012
Posts: 12
Likes: 0
From: TP IL
That brown color shows up on plugs with race gas too. I've used CAM2/Sunoco unleaded racing gas (100 or 104 depending on the source) from Speedway gas stations and race tracks in my area.
Do you change the gap at all? Just curious if wider gaps are ever used with suitable ignition modifications. I understand it's more work on the ignition to jump the wider gap. But wider plug gaps are also sometimes useful to make more power? Just asking. Not say this is something you should do
Do you change the gap at all? Just curious if wider gaps are ever used with suitable ignition modifications. I understand it's more work on the ignition to jump the wider gap. But wider plug gaps are also sometimes useful to make more power? Just asking. Not say this is something you should do
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
Yeqh, on my old setup my plugs would always look new even after a few months of driving and racing. Thats why I was surprised by the color this last time. Ill give the new plugs a nice little run and then check them out.
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
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From: SoCal CA
That brown color shows up on plugs with race gas too. I've used CAM2/Sunoco unleaded racing gas (100 or 104 depending on the source) from Speedway gas stations and race tracks in my area.
Do you change the gap at all? Just curious if wider gaps are ever used with suitable ignition modifications. I understand it's more work on the ignition to jump the wider gap. But wider plug gaps are also sometimes useful to make more power? Just asking. Not say this is something you should do
Do you change the gap at all? Just curious if wider gaps are ever used with suitable ignition modifications. I understand it's more work on the ignition to jump the wider gap. But wider plug gaps are also sometimes useful to make more power? Just asking. Not say this is something you should do
Le Mans Master
Joined: Aug 2005
Posts: 5,375
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From: CA.
St. Jude Donor '13-'14-'15
Old school racer here--- Can't really tell by these photos --however this is how I was taught a 100 years ago
1st to read timing on the plug:
You go to the plug strap--and look for-- where the color changes on the strap--very difficult to read old plugs-- best is to use new ones---I like to use NGK plugs as the cadium plating is there to burn off cleanly when 1st ran and it's very easy to see where the color changes-----
Ideally you want the color change to be on the CURVE of the starp
IF the color change is more towards the strap end--Needs more timing
IF the color change goes down towards or into the threads--too much timing
As far a fuel goes (rich/lean) you have to get a magnifying glass and look into the plug's core----
Again very difficult to read with any plug that has been run much
Ideally you would want some color to grow up from the bottom of the core porcelain apprx. 1/16" to 2/16"
More than 2/16" would make it on the RICH side
Less than 1/16" woud make it on the LEAN side
NO color would be VERY LEAN
Fuel additives make the plugs inaccurate to read this way beacuse the additives change the fuel burn
Best is to mix some race gas with premium fuel to raise octane
1st to read timing on the plug:
You go to the plug strap--and look for-- where the color changes on the strap--very difficult to read old plugs-- best is to use new ones---I like to use NGK plugs as the cadium plating is there to burn off cleanly when 1st ran and it's very easy to see where the color changes-----
Ideally you want the color change to be on the CURVE of the starp
IF the color change is more towards the strap end--Needs more timing
IF the color change goes down towards or into the threads--too much timing
As far a fuel goes (rich/lean) you have to get a magnifying glass and look into the plug's core----
Again very difficult to read with any plug that has been run much
Ideally you would want some color to grow up from the bottom of the core porcelain apprx. 1/16" to 2/16"
More than 2/16" would make it on the RICH side
Less than 1/16" woud make it on the LEAN side
NO color would be VERY LEAN
Fuel additives make the plugs inaccurate to read this way beacuse the additives change the fuel burn
Best is to mix some race gas with premium fuel to raise octane
Burning Brakes
Joined: Jan 2008
Posts: 941
Likes: 3
From: Grand Rapids MI
Isn't it kind of pointless to "read plugs" on anythign but a dedicated drag car? If you make one hit, coast back to the pits, and pull them out, then yes it could tell you a lot of great information. After you DD it at 14.7 and light load, wouldn't the plug be seeing so many varying conditions that it would be unreadable, besides extreme cases?
(These are not rhetorical questions. I am genuinely asking.)
Jack
(These are not rhetorical questions. I am genuinely asking.)
Jack
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
Likes: 137
From: SoCal CA
Isn't it kind of pointless to "read plugs" on anythign but a dedicated drag car? If you make one hit, coast back to the pits, and pull them out, then yes it could tell you a lot of great information. After you DD it at 14.7 and light load, wouldn't the plug be seeing so many varying conditions that it would be unreadable, besides extreme cases?
(These are not rhetorical questions. I am genuinely asking.)
Jack
(These are not rhetorical questions. I am genuinely asking.)
Jack
Thread Starter
Safety Car
Joined: Apr 2007
Posts: 3,582
Likes: 137
From: SoCal CA
