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Re: Who sells NGK BCP6ES?
[Re: Sniper]
#3145816
05/20/23 03:08 PM
05/20/23 03:08 PM
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Joined: Jan 2003
Posts: 21,513
N.E. OHIO, USA
A12
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 21,513
N.E. OHIO, USA
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As you increase the ohmic resistance of the sparking system,
either by adding a resistor to the spark plug
or adding resistance to the wire,
the “burn time” of the spark increases.
Having a very intense spark with high current but for very short time,
by experiment has been found to result in more “misfires.”
Lowest misfire rate happens at the compromise where the spark intensity is “good enough” and when the time the spark endures is relatively long,
by experiment has been found to result in lowest possible misfires rate,
At high rpm a single coil does not have time to “recover” before the next cylinder fires.
Misfire rate at high rpm can be reduced at by having a coil for each cylinder.
Misfire rate can be further reduced by having two (or more) spark plugs per cylinder, each with its own coil.
( 5.7 Hemi set up)
Seems excessively crazy,
but an MIT student wrote his Master’s thesis about finding how many spark plugs per cylinder were needed to reduce the misfire rate to zero.
He got up to 16 spark plugs on a single cylinder and was still finding improvement.
The single cylinder, variable compression ratio, side valve design, CFR engine he was using has a combustion chamber design that lacks modern “overhead valve” engine design with quench, swirl, or tumble.
Your MIT example negates your increased resistance claim. As you add resistance in parallel ( more plugs in this case) over all resistance drops. You need to cite both claims to make a coherent conclusion. And bet he never built a race engine and did dyno testing to prove or disprove his findings   
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Re: Who sells NGK BCP6ES?
[Re: 70sixpkrt]
#3145889
05/20/23 07:53 PM
05/20/23 07:53 PM
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Joined: Jan 2003
Posts: 31,041
Oregon
AndyF
I Win
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I Win
Joined: Jan 2003
Posts: 31,041
Oregon
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Who sells NGK 4930 (BCP6ES)? Summit says they have been discontinued. If this is a street car then take a look at NGK 6987. It has a projected tip and an extra wide spark gap. I use the 6987 on all of my street engines, even use them on pump gas race engines. Best plug for the price that I've found.
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Re: Who sells NGK BCP6ES?
[Re: AndyF]
#3145894
05/20/23 08:02 PM
05/20/23 08:02 PM
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Joined: Jan 2003
Posts: 3,682
South San Francisco, Ca
70sixpkrt
OP
master
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OP
master
Joined: Jan 2003
Posts: 3,682
South San Francisco, Ca
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Who sells NGK 4930 (BCP6ES)? Summit says they have been discontinued. If this is a street car then take a look at NGK 6987. It has a projected tip and an extra wide spark gap. I use the 6987 on all of my street engines, even use them on pump gas race engines. Best plug for the price that I've found. Thank you. It is a street car with Edelbrock heads and 500hp.
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Re: Who sells NGK BCP6ES?
[Re: A12]
#3145955
05/21/23 08:19 AM
05/21/23 08:19 AM
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Joined: Jan 2006
Posts: 8,162
USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
|
As you increase the ohmic resistance of the sparking system,
either by adding a resistor to the spark plug
or adding resistance to the wire,
the “burn time” of the spark increases.
Having a very intense spark with high current but for very short time,
by experiment has been found to result in more “misfires.”
Lowest misfire rate happens at the compromise where the spark intensity is “good enough” and when the time the spark endures is relatively long,
by experiment has been found to result in lowest possible misfires rate,
At high rpm a single coil does not have time to “recover” before the next cylinder fires.
Misfire rate at high rpm can be reduced at by having a coil for each cylinder.
Misfire rate can be further reduced by having two (or more) spark plugs per cylinder, each with its own coil.
( 5.7 Hemi set up)
Seems excessively crazy,
but an MIT student wrote his Master’s thesis about finding how many spark plugs per cylinder were needed to reduce the misfire rate to zero.
He got up to 16 spark plugs on a single cylinder and was still finding improvement.
The single cylinder, variable compression ratio, side valve design, CFR engine he was using has a combustion chamber design that lacks modern “overhead valve” engine design with quench, swirl, or tumble.
Your MIT example negates your increased resistance claim. As you add resistance in parallel ( more plugs in this case) over all resistance drops. You need to cite both claims to make a coherent conclusion. And bet he never built a race engine and did dyno testing to prove or disprove his findings The Master’s student did have a dyno measuring the output of his little CFR engine with one cylinder and whose side valve head design is about as far from “modern race engine” as one can imagine. The idea that he was also so clueless that he hooked up 16 spark plugs to a single ignition coil so as to create 16 parallel electrical circuits with lower ohms of circuit resistance says more about Sniper’s view of reality than even I previously suspected. There were 16 separate ignition systems to insure each spark was equivalent. But the sparks were not anywhere near “optimum” combustion chamber locations, especially spark locations 5 through 16. Imagine drilling and tapping 16 holes without having a crack run from one close hole to another. Give the little CFR engine with its variable compression ratio its due respect though. It was used to discover Octane, Triptane, Tetra-Ethyl Lead and other “Octane Rating Improvement Additives” At one time these were valuable “Military Advantages.” MIT PhD student Col Jimmy Dolittle used 130 Octane Rating Triptane aviation fuel during his bomber raid on Tokyo. Did this student go onto a job with Chrysler/Ford/General Motors/Other where he designed, built, and dyno tested engines? I do not know but I would not be surprised if he did.
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Re: Who sells NGK BCP6ES?
[Re: 360view]
#3145960
05/21/23 08:58 AM
05/21/23 08:58 AM
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Joined: Jan 2006
Posts: 8,162
USA
360view
Moparts resident spammer
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Moparts resident spammer
Joined: Jan 2006
Posts: 8,162
USA
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If you have a projected nose, should you worry at all about the longer ground strap getting too hot at high load? https://www.enginelabs.com/engine-t...lug-debate-separating-fact-from-opinion/Along with longer ground strap changes, what about multiple ground strap changes? Autolite view: https://www.autolite.com/docs/defau...s/understanding-mge-spark-plugs-2017.pdfI confess to spending way to much time indexing spark plugs, cutting off with a Dremel tool the particular ground straps of Bosch +4 that ended up nearest the exhaust valve off, making them into custom Bosch+3. I now like NGK Iridium projected nose plugs where great factory quality control and longer life justifies higher cost. I like the no longer sold KAL Equip 2969 spark plug analyzer with its Peak KV, Burn KV and burn time readings, although it does not work well with “wasted spark” type ignition systems. I eventually bought another used KAL Equip 2969 unit for $70 to have two so as to more easily compare “known good” cylinder to “suspect” cylinder at the same instant in time. If you “on purpose” create an air leak at a cylinder for lean a/f or add propane to a cylinder to create richer a/f the KAL 2969 is sensitive enough with its 3 readouts to show a/f differences.
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Re: Who sells NGK BCP6ES?
[Re: 360view]
#3145968
05/21/23 10:11 AM
05/21/23 10:11 AM
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Joined: May 2019
Posts: 6,261
nowhere
Sniper
master
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master
Joined: May 2019
Posts: 6,261
nowhere
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The Master’s student did have a dyno measuring the output of his little CFR engine with one cylinder and whose side valve head design is about as far from “modern race engine” as one can imagine.
The idea that he was also so clueless that he hooked up 16 spark plugs to a single ignition coil so as to create 16 parallel electrical circuits with lower ohms of circuit resistance says more about Sniper’s view of reality than even I previously suspected.
There were 16 separate ignition systems to insure each spark was equivalent.
But the sparks were not anywhere near “optimum” combustion chamber locations, especially spark locations 5 through 16.
Imagine drilling and tapping 16 holes without having a crack run from one close hole to another.
Give the little CFR engine with its variable compression ratio its due respect though.
It was used to discover Octane, Triptane, Tetra-Ethyl Lead and other “Octane Rating Improvement Additives”
At one time these were valuable “Military Advantages.”
MIT PhD student Col Jimmy Dolittle used 130 Octane Rating Triptane aviation fuel during his bomber raid on Tokyo.
Did this student go onto a job with Chrysler/Ford/General Motors/Other where he designed, built, and dyno tested engines?
I do not know but I would not be surprised if he did.
The cluelessness is your assumption he used 16 separate ignition systems. You claim chit without sourcing and try to come off as oh so superior when called on it, lol. Care to talk about wasted spark systems? that have parallel paths to ground and what that does to resistance?
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