Rat Bastid
Dunamis Metron
Me either. I have proven many times on the dyno and at the track that you don’t set the heat range by the ground strap. Since I can prove that and duplicate it, I say it’s wrong.
Plug read, opinions needed
- Thread starter TT5.9mag
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Me either. I have proven many times on the dyno and at the track that you don’t set the heat range by the ground strap. Since I can prove that and duplicate it, I say it’s wrong.
TT5.9mag
Two atmospheres are better than one
And you don’t set fueling or jetting by the color of the base thread. That’s what I dont like about it.
MOPAROFFICIAL
Oogliboogli
Maybe fuel is separating/ and that's a tell of a vorticie at the plug on those cylinders.
I'd look at maybe what's different in the heads/ports..like any blending near or at the valve job..and at the chamber too.
Intially I think wet/u burnt fuel when I see it in the one pic .
A couple more views.
Both guys have worked a lot with tuning race engines on dynos and at the track.
Bruce "Shrinker" Robertson: The direct link I posted in that thread still works. PDF format.
racingfuelsystems-Shrinker on Spark plug reading
This goes in pretty deep, with each example discussed in context with the specific engine and other measurements.
Larry Meaux on the basics: HTML (web format) sparkplugreading
Note - I don't know how old this is, and so Larry may have changed his conclusions since it was posted.
edit: Direct link to pdf available as FABO attachment later in this thread
Both guys have worked a lot with tuning race engines on dynos and at the track.
Bruce "Shrinker" Robertson: The direct link I posted in that thread still works. PDF format.
racingfuelsystems-Shrinker on Spark plug reading
This goes in pretty deep, with each example discussed in context with the specific engine and other measurements.
Larry Meaux on the basics: HTML (web format) sparkplugreading
Note - I don't know how old this is, and so Larry may have changed his conclusions since it was posted.
edit: Direct link to pdf available as FABO attachment later in this thread
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Snake
Mopar Nut
need more timing.
TT5.9mag
Two atmospheres are better than one
Thanks for the links. I like reading anything Bruce has written and I value his opinion. Although I am a taptalk member, the link provided the dreaded “Access denied” page. Do you have another source for that article? The Larry Meaux article is the same one that has been regurgitated by many a online magazine and I dont give much credence to it. I will say it is the only article I’ve read that addresses this exact tip coloration on the strap so maybe I need to open my mind a little.
TT5.9mag
Two atmospheres are better than one
I addressed this comment in post 6. Unless you can substantiate this statement with fact, I will ask that you stop making it. I have two hours of dyno data running timing sweeps that suggest this engine is happy right where it’s at. Thanks
70DusterDev
Well-Known Member
Hey Mike, I think this is the same file that wouldn't download? It was also in that thread.
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I'd be curious about larry's current opinion on it. I think like Bruce, his opinions evolved over time thorugh experience and personal observations and testing.
Try this direct link for Shrinker's paper.
http://gallery.myff.org/gallery/1486369/Sparkplug+reading.pdf
If that fails I'll try to load it here although I've not had much luck attaching pdfs
TT5.9mag
Two atmospheres are better than one
That worked perfectly thank you.
Not bein a smartass at all but just throwin this out there. You could have tried some hotter plugs by now "just to try it" in the time you've been battin it around here. You said you have 7s in it now? On the NGK plugs, aren't the plugs hotter going down in number? I think that's right. I'd try 5s and see what they look like. It's not like it's a big expense and it takes almost no time.
Rat Bastid
Dunamis Metron
I read what LM say too. That just does not square with my experience.
As an example, I have a buddy who got into the weeds on his tune up. We are talking on the phone about and he has a heat range that made no sense to me. I asked him how he came up with that plug and he said he was reading the ground strap for heat range.
I said I can show you that it doesn’t work that way. The next week I met him at the track.
We started with his plugs. I backed him timing from 39 total to 30 total. And the heat mark on the ground strap moved right back to the end.
At 39 he was right at the bend. So I put 42 in it and that moved the heat mark almost to the shell. And it went a bit quicker there.
After that, I showed him how the fuel ring moves. I put 10 sizes bigger main jets in it, and the fuel ring was wider. I could see he was fat when I started so I went 6 sizes smaller from his base line. And the fuel ring narrowed up to just about perfect.
After that, we put everything back to his baseline tune up and went 2 ranges colder on plug. The heat mark on the ground strap didn’t move one iota. I didn’t want to go any hotter on plug because he was already too hot IMO.
I had him look at the plug he was running and the plug two ranges colder. What changed was the burn down the threads on the shell. The colder plug had about 2 threads showing heat. The plug he was using was a bit over 4 threads.
By then we were out of time, but a week later we went back and started out with his baseline tune up and made two passes. Then we went to the colder plugs, pulled fuel out of it and set the timing to 42 and the car picked up .15.
After all that, he stopped looking at the ground wire to set his heat range. He moved quite a ways away so I don’t see him too often any more. I talk to him a couple times a month. He gets paid to do at the track tuning.
TT5.9mag
Two atmospheres are better than one
TT5.9mag
Two atmospheres are better than one
Rusty, this engine was run and tuned on the dyno during one full day. The engine is now on a pallet mocking me waiting for me to install it in the boat. I pulled the plugs after the last dyno run to get a read on them. Trust me there will be some testing done after it’s in the boat, but that is impossible now.
Well it looks good! I love the old Mark IV engines. They can make some big power.
TT5.9mag
Two atmospheres are better than one
I have had very similar tuning experiences where on an engine that I’ll call close on the tune up you can change one variable, be it heat range or jet or even coolant temp and see the effects on the plug. I could be wrong, but I have never seen the heat range on a healthy engine with a decent tune up effect the ground strap.
TT5.9mag
Two atmospheres are better than one
Thanks. This is a gen6 block. We were all kind of surprised at the torque curve this thing has. At one point Someone in the cell said, “that thing makes torque like a train” and it did it on very little boost. We didn’t pull it lower than 3000 but on every pull it made over 700lb/ft the entire way. Like a table top.
That's pretty funny. I've always said all you gotta do is bolt a big block together and it's gonna make power.
TT5.9mag
Two atmospheres are better than one
Then add some snails and watch the needle move.
70DusterDev
Well-Known Member
Interesting, and do you trust what he has to say?
TT5.9mag
Two atmospheres are better than one
I value his testing and experience a lot. Anyone who doesn’t is crazy. The guy was borderline genius. But like @Rat Bastid my experience has led me to believe something different. And I’ve been in some circles of well respected people that I guarantee you would have a different opinion. But this is how we learn.
apparently folks down under thought he made their head shrink. LOL
Makes mine think its going to explode.
I read it (page 10) that he couldn't correlate it.
There is no evidence of overheating. The line on the strap electrode that is near the weld
is sometimes interpreted by tuners to be evidence of the ideal ignition timing. The rule is
often quoted as being to adjust the timing so that the line appears in the middle of the
bend of the strap electrode. I do not agree with this theory. There is ample evidence from
improved atomization style burns that this line exists only under some conditions and I
have not been able to establish a link to the optimum timing degree. It is not as simple as
that.
But as he wrote in the begining, all these things are contextual. So under certain conditions we see different things than other conditions. If you move timing and see the line on the strap move - then there is a relation. Is it because the timing changed or because the way the flame developed? Lets say its the latter. Well maybe that doesn't matter to us because we only have limited tools to change the atomization - where for him, he might change the booster or even the combustion chamber depending on the project. For us, we just want to optimize what we got so we focus on timing, amnd maybe something simple like trying to direct a litle more fuel toward or away from a cylinder.
Just thowing that out as possible explanation. He thought about everything from the inside out - he'd start with how did it burn, based on what evidence did it left and then work toward what caused it to burn that way.
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