PLUG READING FOR A NITROUS MOTOR

General Nitrous Discussion

Moderator: John_Heard

Post Reply
Message
Author
User avatar
gearjammer
Posts: 228
Joined: Tue May 17, 2005 7:57 am
Location: Michigan
Contact:

PLUG READING FOR A NITROUS MOTOR

#1 Post by gearjammer » Tue May 17, 2005 9:09 am

Phil aka Gearjammer
JPR Racing
1972 Nova
Drag Radial

User avatar
John_Heard
Site Admin
Posts: 5682
Joined: Thu May 12, 2005 11:20 am
Location: Resume Speed, Kansas
Contact:

#2 Post by John_Heard » Tue May 17, 2005 10:37 am

That article of Monty's needs better pictures.

I've started taking pictures of various plugs, but need to get a lot more showing things clearly. Here's a picture of a plug out of my car, last pass of the year. This clearly shows the fuel line and that the car was running rich. Also you can see some specks on the porcelin, that might have been caused by the use of Torco 118 fuel. Some people have noted seeing that condition when using that fuel, but don't know why that fuel does it.

Image

I'd like to get a collection of "perfect" looking plugs, and plugs showing various stages of tune.. Too much timing, too little timing, too much fuel, too lean, etc.

I think a very complete picture gallery with comments on what to do would help a lot of nitrous guys out.

Mike Canter wrote a pretty good article about plug reading that we have in our technical section of the site http://www.dragstuff.com/techarticles/r ... plugs.html however it needs pictures.

Here's another one that is interesting.. This plug was taken out of Bob Stahl's 69 Camaro last year after a pass. It's an Autolite. What makes it interesting is that this plug quit firing on the previous pass. All the other plugs in the engine were light grey from soot. But this one is clean.. The fire went out in this cyl and the fuel was washing the soot off. He switched to a new plug and the miss went away. On a side note, I check this plug with an ohm meter, and is was very close to the same resistance as a NGK, nothing obviously wrong with it.


Image

Bobalos
Posts: 39
Joined: Wed May 18, 2005 12:09 pm
Contact:

#3 Post by Bobalos » Wed May 18, 2005 1:54 pm

I had a discussion with Butch a couple of weeks ago about the light "pepper" type of detonation. in short it went something like this.
silver balls............ Duh.... what about those light pepper things. what is that?
As usual he answered my question with a question. "how many "large" detonation events does it take to create one silver speck?". "how many "small" detonation events does it take to create one piece of "pepper""? the answer is that you dont get one speck for one event. SO.................. if you have X number of specs you have some larger number of detonation events creating that One spec.

I am running a pretty mild combination with a 200 HP shot & C16 so there is not a lack of Octane, so what this told me was that I needed to yank more timing. I was only getting a VERY small amount of pepper on a few of my plugs so I yanked one more degree out while on the kit & Bingo, not a single spec.

I have yet to yank the plugs on it, but I will & will try to get some good shots of it. these plugs are as close to "perfect" as I am comfortable getting them.

Bob

User avatar
John_Heard
Site Admin
Posts: 5682
Joined: Thu May 12, 2005 11:20 am
Location: Resume Speed, Kansas
Contact:

#4 Post by John_Heard » Thu May 19, 2005 11:57 am

Those spec's on mine very well might have been from detonation.. On that pass the rings were about shot but it didn't have a lot of timing in it.

I can't wait to see how it's going to work all sealed up this year and get to tuning on the new system... Should be too much longer!!! :D

terryw

PLUGS

#5 Post by terryw » Thu May 19, 2005 3:10 pm

I HAVE A COUPLE OF PLUG PICS BUT I DON'T KNOW HOW TO POST PICS. CAN SOMEONE TELL ME HOW TO POST THEM? [/img][/list]

User avatar
John_Heard
Site Admin
Posts: 5682
Joined: Thu May 12, 2005 11:20 am
Location: Resume Speed, Kansas
Contact:

#6 Post by John_Heard » Thu May 19, 2005 3:17 pm

Hi Terry, in order to post a picture the image has to be on a webserver somewhere. Our board doesn't have an upload feature. If you want to email them to admin@dragstuff.com I"ll post them for you.

User avatar
John_Heard
Site Admin
Posts: 5682
Joined: Thu May 12, 2005 11:20 am
Location: Resume Speed, Kansas
Contact:

#7 Post by John_Heard » Fri May 20, 2005 9:11 am

Here's Terry's Plugs - AR3933's
Image
Image
Image

User avatar
Craig W.
Posts: 1254
Joined: Thu May 12, 2005 11:01 am
Location: Columbia, KY
Contact:

#8 Post by Craig W. » Tue May 24, 2005 7:32 am

I've seen new plugs, right out of the box have "pepper" on them. Sure makes it hard to tell what is detonation and what isn't! They were Autolite race plugs. Have you guys seen this too?
Craig Watson
2QuickNovas Racing
5.27@130

Sponsors:
AEM Electronics
Carnivore Performance
Bradco Converters
Rapp Racing
VFN Fiberglass

User avatar
John_Heard
Site Admin
Posts: 5682
Joined: Thu May 12, 2005 11:20 am
Location: Resume Speed, Kansas
Contact:

#9 Post by John_Heard » Tue May 24, 2005 7:54 am

Those are plenty clear Monty! I must have looked at it before you put those pictures up, last time I looked at your page I only remember seeing the uncut ones. What fuel were you using? I've noticed that different fuels tend to color the plugs differently some are grey others more black. Seems like Torco fuels are black, VP is more Grey?

BTW, welcome to the forum too Monty, make sure and stop by again when you have the time.

FYI - Monty's plug reading page we're talking about is the one Phil posted at the top of this post http://www.yellowbullet.com/yellowbullet1_010.htm

Craig I've never seen new ones with pepper yet..at least on NGK's.

User avatar
Craig W.
Posts: 1254
Joined: Thu May 12, 2005 11:01 am
Location: Columbia, KY
Contact:

#10 Post by Craig W. » Tue May 24, 2005 8:03 am

Beyond wrote: Craig I've never seen new ones with pepper yet..at least on NGK's.
What I've seen is really, really small and usually only seen through my plug reading glass. Is real pepper usually larger than that?
Craig Watson
2QuickNovas Racing
5.27@130

Sponsors:
AEM Electronics
Carnivore Performance
Bradco Converters
Rapp Racing
VFN Fiberglass

User avatar
John_Heard
Site Admin
Posts: 5682
Joined: Thu May 12, 2005 11:20 am
Location: Resume Speed, Kansas
Contact:

#11 Post by John_Heard » Tue May 24, 2005 8:23 am

I've seen it on my plugs without a magnifying glass with too much timing in it, other times it's pretty light, hard to see without a visual aid.

Monty Mikho

#12 Post by Monty Mikho » Tue May 24, 2005 9:53 am

"I made this post on another board and cut and pasted it here"

Here are some sample plugs. They were sitting around for a little while and the reason behind the rust spots. The top plug is on a perfect pass with nitrous and shows the heat mark at thebase of the ground strap. The heat mark will work its way down the thread as you increase timing. It will work it way up the ground strap as you remove timing

The bottom plug is very rich. You can see the fuel ring work its way down the porcelain as the tune up gets leaner. Becareful when adjusting timing and fuel. As you add timing it will also work the fuel ring down towards the base. Do one at a time unless either are at the edge.

If your tune-up is leaner than the top picture. You will see small specs of aluminum on the porcelain. Make sure you do not mistake it for the cadmium plating the NGK uses. The cadmium plating is also used as a tune-up tool. When the cadmium flakes your timing is close to perfect. If it flakes + shows heat you will need to back the timing off...

Hope that makes sense somewhat... Also make sure you invest in a nice sparkplug inspection tool. The ear scopes seem to work best..

Monty Mikho

#13 Post by Monty Mikho » Tue May 24, 2005 9:57 am

Beyond, that was on VP-NOS or N2O or whatever they're calling it now.. The fuel has no color additives like Torco uses... For Torco 118 NOS they add purple.. You will see some of the color transfer to the plug and make it a little easier to read... VP just makes a cleaner fuel and is the reason why I use it now...

Bobalos
Posts: 39
Joined: Wed May 18, 2005 12:09 pm
Contact:

#14 Post by Bobalos » Tue May 24, 2005 10:06 am

I found the same thing with the Sonoco Fuel, it made it hard to read, kind of deceptive what was going on, on the plug.

thanks for the pictures Monty, those are GREAT. Looks like you used a Lath to cut them open, NICE!!!!

Bob

Fast Lane N20
Posts: 1
Joined: Wed May 25, 2005 11:31 am
Location: Tyler, Texas
Contact:

#15 Post by Fast Lane N20 » Wed May 25, 2005 12:05 pm

Beyond wrote:That article of Monty's needs better pictures.

I've started taking pictures of various plugs, but need to get a lot more showing things clearly. Here's a picture of a plug out of my car, last pass of the year. This clearly shows the fuel line and that the car was running rich. Also you can see some specks on the porcelin, that might have been caused by the use of Torco 118 fuel. Some people have noted seeing that condition when using that fuel, but don't know why that fuel does it.

Image

I'd like to get a collection of "perfect" looking plugs, and plugs showing various stages of tune.. Too much timing, too little timing, too much fuel, too lean, etc.

I think a very complete picture gallery with comments on what to do would help a lot of nitrous guys out.

Mike Canter wrote a pretty good article about plug reading that we have in our technical section of the site http://www.dragstuff.com/techarticles/r ... plugs.html however it needs pictures.

Here's another one that is interesting.. This plug was taken out of Bob Stahl's 69 Camaro last year after a pass. It's an Autolite. What makes it interesting is that this plug quit firing on the previous pass. All the other plugs in the engine were light grey from soot. But this one is clean.. The fire went out in this cyl and the fuel was washing the soot off. He switched to a new plug and the miss went away. On a side note, I check this plug with an ohm meter, and is was very close to the same resistance as a NGK, nothing obviously wrong with it.


Image
The pepper/specks are the result of the center electrode's edges melting and fusing the metal to the porcelain of the plug. Take a look at the center electrode (Where the spark originates not the ground strap), on the top plug picture. As you can see in the picture the center electrode was melting and the specks are the metal fragments from the center electrode. This is cause by too much ignition advance for the particular fuel you're using. Pull some more timing or examine your fuel selection. Your engine is trying to send you a message.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest