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Re: PLUG READING FOR A NITROUS MOTOR

Posted: Wed Dec 03, 2008 8:49 pm
by azjulian
Its the photo in real life it looks a lot matter and like the previous photo.


what are your thoughts on the timing?

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Thu Dec 04, 2008 7:49 am
by John_Heard
azjulian wrote:Its the photo in real life it looks a lot matter and like the previous photo.


what are your thoughts on the timing?
It appears to be close to the bend, you're pretty close I'd say. Try taking a degree out see if it picks up any. Not sure if I'd try much more than what you have already. How's the fuel ring look down inside?

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Thu Dec 04, 2008 11:35 am
by azjulian
Need to cut them to check properly, will try in the next day or so.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Fri Jan 02, 2009 8:29 pm
by GT4X
Guys,

Today I decided to pull the plugs on my street driven turbo Honda and I found this on #3. I thought it was a little strange maybe someone can explain what might be the cause of this, these plugs aren't very new and I know my idle is rich, well was rich I pulled fuel since then and just never really got around to changing the plugs.

Image

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Sat Jan 03, 2009 6:32 am
by John_Heard
That's kind of hard to say since they are old plugs and the tune up has moved around, but obviously one side is cleaner than the other due to it's orientation in the chamber. My guess is that cyl hasn't finished burning the soot off that side of the plug yet because it's cooler on that side of the chamber.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Sat Jan 03, 2009 6:20 pm
by GT4X
John,

I decided to cut the plug please note I have quite A few WOT runs on this plug, can I assume that i'm rich up top?

Image

Regards,
Kurt Knight

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Sat Jan 03, 2009 6:52 pm
by John_Heard
It appears that it's plenty fat. I think it would be a good idea to put a new set of plugs in it and look again before you make some tuning decisions though, that should give you a better idea of where it's at vs. those plugs with lots of runs on them.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 6:30 am
by Chevyfireball
Hi, Great to see a site like this.
Mikes article talks about the 'blue' line on the ground strap for reading the timing. Why do other articles talk about the dark and light brown on the strap for reading this. I've seen pics that show the browning and one or two pics showing bare metal with blueing.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 6:49 am
by John_Heard
Depends on if the ground strap has a coating on it or not.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 7:03 am
by Chevyfireball
I'm running a 632 with two systems. Autolite plugs equivalent to 9's. The car runs 6.84 quarters at 198mph and is shut off and towed back. I'm having some probs seeing that timing line on the strap. It all appears the same. The fuel ring looks good. No detonation. But I can't see any heat line. Does that mean my timings too advanced? I run 32* initial. First system (400hp) pulls out 11*. 2nd system (300hp) pulls out another 5* leaving a total 16*. What do ya reckon.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 7:33 am
by John_Heard
Chevyfireball wrote:I'm running a 632 with two systems. Autolite plugs equivalent to 9's. The car runs 6.84 quarters at 198mph and is shut off and towed back. I'm having some probs seeing that timing line on the strap. It all appears the same. The fuel ring looks good. No detonation. But I can't see any heat line. Does that mean my timings too advanced? I run 32* initial. First system (400hp) pulls out 11*. 2nd system (300hp) pulls out another 5* leaving a total 16*. What do ya reckon.
It could be hot enough to move the heat mark on the strap past the base where it's welded to the plug body. Can you see any heat signature where the strap contacts the base area? It'll look like an oval mark with the center where the strap contacts the base. You might find NGK's easier to read.

PS> That's a hot plug for that much juice...

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 7:51 am
by Chevyfireball
Re the hot plugs. I was running 10's but they always looked way rich. I was talking to Mike Canter and he said 10's can often look rich when they're not and leaning it out could go all bad. He said 9's were better to read so I switched to them and they are looking a lot better. The ground strap, electrode etc don't seem to be melting or anything. I'll take a look if theres an oval mark and let you know. The car's parked up at my storage shed for the off season along with my plugs etc.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 8:17 am
by John_Heard
You might ask Mike C., but I'd bet he'd say on a 700 hp shot 9's are probably too hot. You should probably be using -10's or -11's and if they show fat, then start backing off on the fuel and timing at the same time.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 8:37 am
by Chevyfireball
Could be right. I was running 250hp on the second shot at the time I talked with Mike. I increased that to 300 at the last meet and advanced the timing 1 degree on each stage. I'll take your advice and go back to 10's. I have a heap of them in my spares anyway. I'm mainly concerned about getting that timing right. Thanks.

Re: PLUG READING FOR A NITROUS MOTOR

Posted: Tue Jun 23, 2009 10:51 pm
by 71Hellride
Chevyfireball wrote:Could be right. I was running 250hp on the second shot at the time I talked with Mike. I increased that to 300 at the last meet and advanced the timing 1 degree on each stage. I'll take your advice and go back to 10's. I have a heap of them in my spares anyway. I'm mainly concerned about getting that timing right. Thanks.
Hey I was curious if your 632 was standard degree or a big cheif motor? That sound like a lot of timing for 700 hp. I also second the opinion on using ngk 10's.