What is the benifit of running a hotter or colder plug.
- Leatherneck
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What is the benifit of running a hotter or colder plug.
So from what I understand a plug being hot isn't hotter a hotter plug actually transfers less heat to the head keeping the tip hotter it doesn't burn hotter, a colder plug will transfer more heat to the head. Which is better, higher horsepower, hotter plug, why?
- Piledriver
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Re: What is the benifit of running a hotter or colder plug.
Short: The best plug is whatever your engine likes.
The HP will be the same.
The colder plug simply won't overheat/melt and perhaps cause knocking/preignition at high loads if it glows.
(You MUST run a cold enough plug to prevent this, as it's fatal to the engine RFN)
Unfortunately, a cold plug is likely to load up with carbon at idle/low loads as it won't get hot enough to keep itself clean.
To cure this issue, they make what are known as "extended core" or "extended tip" plugs, where the tip etc are out past the body of the plug.
This setup gets far more cooling at high load from intake air/fuel spray, so it runs like a cold plug at high loads, and a hot plug at low loads.
That solution has existed for many decades, it is a very common plug type, perhaps most plugs fall into that extended description these days.
One more thing the OEMs do to keep the std plugs from melting on hipo engines is greatly enrich the mixture at full loads (10:1-11:1, perhaps even lower) with a delay, in order to keep the std emissions freindly//grocery getting plugs from melting on a long full throttle pull.
The blown GM engines at least do this, and the option for time based load enrichment exists iirc in MS2E and definitely in MS3 firmware.
It would likely also be of some benefit to hipo aircooled engines.
The HP will be the same.
The colder plug simply won't overheat/melt and perhaps cause knocking/preignition at high loads if it glows.
(You MUST run a cold enough plug to prevent this, as it's fatal to the engine RFN)
Unfortunately, a cold plug is likely to load up with carbon at idle/low loads as it won't get hot enough to keep itself clean.
To cure this issue, they make what are known as "extended core" or "extended tip" plugs, where the tip etc are out past the body of the plug.
This setup gets far more cooling at high load from intake air/fuel spray, so it runs like a cold plug at high loads, and a hot plug at low loads.
That solution has existed for many decades, it is a very common plug type, perhaps most plugs fall into that extended description these days.
One more thing the OEMs do to keep the std plugs from melting on hipo engines is greatly enrich the mixture at full loads (10:1-11:1, perhaps even lower) with a delay, in order to keep the std emissions freindly//grocery getting plugs from melting on a long full throttle pull.
The blown GM engines at least do this, and the option for time based load enrichment exists iirc in MS2E and definitely in MS3 firmware.
It would likely also be of some benefit to hipo aircooled engines.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
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Re: What is the benifit of running a hotter or colder plug.
Leather, I am assuming that you are looking for a starting point on your engine so you can then tune you 'plugs from there. think this might be at least part of what you are after:
http://www.hotrod.com/how-to/engine/116 ... lug-guide/
http://www.hotrod.com/how-to/engine/spark-plugs-tips/
More info: http://www.enginebuildermag.com/2011/05 ... eat-range/
http://www.briskusa.com/spark_plug_cros ... ange_chart
Some good info w/a chart.
http://www.hotrod.com/how-to/engine/116 ... lug-guide/
http://www.hotrod.com/how-to/engine/spark-plugs-tips/
More info: http://www.enginebuildermag.com/2011/05 ... eat-range/
http://www.briskusa.com/spark_plug_cros ... ange_chart
Some good info w/a chart.
- Leatherneck
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- Joined: Sat Jul 01, 2006 6:47 pm
Re: What is the benifit of running a hotter or colder plug.
Pile, that is what I am trying to find, it runs with 6's or 8's but always looking for what it really likes.
Lee, thank you for the info, I will stash those in my bookmarks.
Lee, thank you for the info, I will stash those in my bookmarks.
- Piledriver
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Re: What is the benifit of running a hotter or colder plug.
If the plugs aren't overheating or loading up they are fine.Leatherneck wrote:Pile, that is what I am trying to find, it runs with 6's or 8's but always looking for what it really likes.
Lee, thank you for the info, I will stash those in my bookmarks.
On a turbo setup esp I'd run the coldest plug that doesn't load up, in iridium.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
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- Posts: 424
- Joined: Tue Apr 25, 2006 8:13 am
Re: What is the benifit of running a hotter or colder plug.
That's right, and extended core plugs have another important benefit, which I like to sum up by listing the three most important things in real estate: "location, location, and location." In a theoretically perfect engine, the ideal charge shape would be spherical and the ideal point of ignition would be at the center of the charge. Extended core plugs move the spark location further out into the charge itself, as a result the initial flame kernel develops closer to the center of the charge, so burn progression is faster and more complete. I've recommended using the NGK BP6ET plugs in wbx's for years and I can't even count the number of people who have reported noticeably better throttle response and power delivery and smoother idle by just switching to a plug that moves the spark a few mm away from the head and doesn't shade the spark from the center of the charge.Piledriver wrote:To cure this issue, they make what are known as "extended core" or "extended tip" plugs, where the tip etc are out past the body of the plug.
This setup gets far more cooling at high load from intake air/fuel spray, so it runs like a cold plug at high loads, and a hot plug at low loads.
The stock Digifant EFI from the late wbx does this. The throttle position switch is closed when throttle is opened fully, which tells the ECU to go open-loop, ignore the O2 sensor and use the load signal from the AFM to determine mixture without lambda trim, BUT it waits 30 seconds to do so. There are benefits to the plugs for sure but the other reason this strategy is used by some OEMs is to prevent the piston crown from reaching the 600ºF surface temp that can preignite the charge. So they stay in lambda for emissions as long as they can, and only let the system go rich as a failsafe.One more thing the OEMs do to keep the std plugs from melting on hipo engines is greatly enrich the mixture at full loads (10:1-11:1, perhaps even lower) with a delay, in order to keep the std emissions freindly//grocery getting plugs from melting on a long full throttle pull.
The blown GM engines at least do this, and the option for time based load enrichment exists iirc in MS2E and definitely in MS3 firmware.
- Piledriver
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- Joined: Sat Feb 16, 2002 12:01 am
Re: What is the benifit of running a hotter or colder plug.
The NGK BP6ET/ Bosch W7DTC are unusual in several ways, IIRC the side gap triple electrode plugs were developed originally for the UrQuattro. They are also available in different heat ranges.
They are not like razor blades with "more blades!" they do in fact make a noticeable difference, and last a very long time.
They are not like razor blades with "more blades!" they do in fact make a noticeable difference, and last a very long time.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
-
- Posts: 424
- Joined: Tue Apr 25, 2006 8:13 am
Re: What is the benifit of running a hotter or colder plug.
Right, the misconception people commonly have of multi-electrode plugs is that they make multiple sparks at one time, but that would be electrically impossible in practice, only multiple plugs can give you that. Instead, with multiple spark gaps the spark will bridge whichever gap is presently easiest to jump. But some material is carried off by the spark, widening that gap, which will eventually make a different gap more favorable. So there's more spark-grounding area available to be used up, and the spark also moves round and round the entire center electrode so you get more use out of that as well. As these wear, the center pole wears down to a tri-lobe shape, like a Wankel rotor, which is proof that the spark is moving round and round and using all the material resources.
The upper edge of the center pole also stays sharper longer, becoming less rounded off, so spark energy is more focused, creating a hotter flame kernel. The ability to keep spark energy focused like that by retaining a sharp edge is the advantage exotic center tip materials like platinum, etc. bring to the game. A copper tip will never approach that kind of edge durability, but moving the spark all around the top edge of a copper tip makes the best use of a limited resource.
Since the ground electrodes approach the center pole from the sides, rather than over the tip like a standard plug construction, the gap is not shaded by the ground electrode, so the flame kernel itself and the heat radiating from it can expand directly toward the center of the charge rather than only sideways. This gets the main body of the charge burning sooner, and flame propagation proceeds outward from there.
Overall the simple differences in where the spark occurs can result in notably faster and more complete combustion, which is the holy grail of engine design. Combine it with a high-squish combustion chamber/head design, and you can have an engine with lower BSFC on less spark advance that is highly resistant to deto.
I don't consider them an especially long-lived plug, but during their useful life they consistently deliver superior ignition characteristics.
The upper edge of the center pole also stays sharper longer, becoming less rounded off, so spark energy is more focused, creating a hotter flame kernel. The ability to keep spark energy focused like that by retaining a sharp edge is the advantage exotic center tip materials like platinum, etc. bring to the game. A copper tip will never approach that kind of edge durability, but moving the spark all around the top edge of a copper tip makes the best use of a limited resource.
Since the ground electrodes approach the center pole from the sides, rather than over the tip like a standard plug construction, the gap is not shaded by the ground electrode, so the flame kernel itself and the heat radiating from it can expand directly toward the center of the charge rather than only sideways. This gets the main body of the charge burning sooner, and flame propagation proceeds outward from there.
Overall the simple differences in where the spark occurs can result in notably faster and more complete combustion, which is the holy grail of engine design. Combine it with a high-squish combustion chamber/head design, and you can have an engine with lower BSFC on less spark advance that is highly resistant to deto.
I don't consider them an especially long-lived plug, but during their useful life they consistently deliver superior ignition characteristics.
- Leatherneck
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Re: What is the benifit of running a hotter or colder plug.
Very good info guys, thanks for taking the time out to put it on the forum.
- Piledriver
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Re: What is the benifit of running a hotter or colder plug.
Leather, there are 12mm versions of that plug type out there, so even if you have 12mm plug heads, they can still be used.
The most reliable way to make an UrQuattro perform horribly is put different plugs in it.
They were specifically developed for highly boosted engines.
They aren't even expensive.
The most reliable way to make an UrQuattro perform horribly is put different plugs in it.
They were specifically developed for highly boosted engines.
They aren't even expensive.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
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What is the benifit of running a hotter or colder plug.
What's the "hot tip" for a type 4 then? The same or a different heat range?
Last edited by Bruce.m on Wed Apr 08, 2015 12:57 am, edited 1 time in total.
- Piledriver
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Re: What is the benifit of running a hotter or colder plug.
I like the W7TDC or BP6ET or the T4 as well.
(Bosch or NGK, respectively, equivalent, the NGK easier to get a hold of around here)
Colder versions of both exist if needed.
(Bosch or NGK, respectively, equivalent, the NGK easier to get a hold of around here)
Colder versions of both exist if needed.
Last edited by Piledriver on Wed Apr 08, 2015 1:04 am, edited 1 time in total.
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
-
- Posts: 782
- Joined: Sun Aug 11, 2013 1:44 pm
- raygreenwood
- Posts: 11895
- Joined: Wed Jan 22, 2003 12:01 am
Re: What is the benifit of running a hotter or colder plug.
Yes....awesome plug. The BP6ET and Bosch W7DTC are just about the best plugs I have found for type 4. The higher the compression and better the coil system....the better these plugs work.
Also...contrary to popular belief....they can be regapped. Just use the right type gauge. Bosch makes a very nice gap gauge that is made just for these type of plugs but can be used on all plugs. Its a pin type gauge. Yellow colored.....looks like a folding straight razor. The part # for the gap gauge is 0 986 600 000. They are about $12. Ray
http://s1186.photobucket.com/user/raygr ... 0.jpg.html
My secret stash of Bosch W7DTC....about 20 sets
http://s1186.photobucket.com/user/raygr ... 6.jpg.html the Bosch gap gauge set closed
http://s1186.photobucket.com/user/raygr ... 7.jpg.html The gauge set open
Also...contrary to popular belief....they can be regapped. Just use the right type gauge. Bosch makes a very nice gap gauge that is made just for these type of plugs but can be used on all plugs. Its a pin type gauge. Yellow colored.....looks like a folding straight razor. The part # for the gap gauge is 0 986 600 000. They are about $12. Ray
http://s1186.photobucket.com/user/raygr ... 0.jpg.html
My secret stash of Bosch W7DTC....about 20 sets
http://s1186.photobucket.com/user/raygr ... 6.jpg.html the Bosch gap gauge set closed
http://s1186.photobucket.com/user/raygr ... 7.jpg.html The gauge set open
- Piledriver
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- Posts: 22518
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Re: What is the benifit of running a hotter or colder plug.
Ray it who put me onto the w7dtc plugs to begin with.
They sell a "copper plus" version that has a yttrium alloyed center electrode as well, and two different tip extensions.
(the ground electrodes are yttrium alloyed on the std plugs, w/ large nickel/copper center electrode)
Have only found them for sale in Europe
They sell a "copper plus" version that has a yttrium alloyed center electrode as well, and two different tip extensions.
(the ground electrodes are yttrium alloyed on the std plugs, w/ large nickel/copper center electrode)
Have only found them for sale in Europe
Addendum to Newtons first law:
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.
zero vehicles on jackstands, square gets a fresh 090 and 1911, cabby gets a blower.
EZ3.6 Vanagon after that.(mounted, needs everything finished) then Creamsicle.