Plug gaps for MSD systems
Tech Contributor
Joined: Jun 2004
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
the secondary windings in the coil multiply the 12-14 volts going
into the primary, the old round type original coil put out 20,000
volts, some of same type aftermarket round coils with more windings
in the secondary can do say 30,000 volts. by comparison the modern
coils on the LS engines put out 120,000 volts and each one only has
to do the work of firing one cylinder. some of the new e-coils for
old cars 60,000 volts. but no matter the coil, if you
take a coil and the secondary windings are multiplying the 12 to14
volts, depending on coil 20,,30,,60,000 volts. now what happens if
the secondary windings of these same coils are no longer multipling
12 to 14 volts they are multiplying 500 volts with the box added.
500 volts is roughly 41 times the amount of volts going into the primary
of the coil compaired to just 12 volts.
into the primary, the old round type original coil put out 20,000
volts, some of same type aftermarket round coils with more windings
in the secondary can do say 30,000 volts. by comparison the modern
coils on the LS engines put out 120,000 volts and each one only has
to do the work of firing one cylinder. some of the new e-coils for
old cars 60,000 volts. but no matter the coil, if you
take a coil and the secondary windings are multiplying the 12 to14
volts, depending on coil 20,,30,,60,000 volts. now what happens if
the secondary windings of these same coils are no longer multipling
12 to 14 volts they are multiplying 500 volts with the box added.
500 volts is roughly 41 times the amount of volts going into the primary
of the coil compaired to just 12 volts.
Last edited by Little Mouse; Aug 20, 2007 at 01:00 AM.
Pro
Joined: Jun 2005
Posts: 725
Likes: 1
From: FL.
Quote:/You gave me marketing hype. I asked for engineering data. Trust me, there is a world of difference between those two items.
ps: Let's also cut the personal comments. I'm trying to have a technical discussion here. Please restrict it to that.\Quote
Looks to me Like Theres a Uptight "electrical Design Engineer" Thats Hijacked this Thread...Adios
ps: Let's also cut the personal comments. I'm trying to have a technical discussion here. Please restrict it to that.\Quote
Looks to me Like Theres a Uptight "electrical Design Engineer" Thats Hijacked this Thread...Adios
Last edited by 69vettester; Aug 20, 2007 at 08:27 AM.
Tech Contributor
Joined: Jun 2004
Posts: 20,827
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Quote:/You gave me marketing hype. I asked for engineering data. Trust me, there is a world of difference between those two items.
ps: Let's also cut the personal comments. I'm trying to have a technical discussion here. Please restrict it to that.\Quote
Looks to me Like Theres a Uptight "electrical Design Engineer" Thats Hijacked this Thread...Adios
ps: Let's also cut the personal comments. I'm trying to have a technical discussion here. Please restrict it to that.\Quote
Looks to me Like Theres a Uptight "electrical Design Engineer" Thats Hijacked this Thread...Adios
What part of "cut the personal comments" was unclear?
Tech Contributor
Joined: Jun 2004
Posts: 20,827
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Tech Contributor
Joined: Jun 2004
Posts: 20,827
Likes: 959
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
the secondary windings in the coil multiply the 12-14 volts going
into the primary, the old round type original coil put out 20,000
volts, some of same type aftermarket round coils with more windings
in the secondary can do say 30,000 volts. by comparison the modern
coils on the LS engines put out 120,000 volts and each one only has
to do the work of firing one cylinder. some of the new e-coils for
old cars 60,000 volts. but no matter the coil, if you
take a coil and the secondary windings are multiplying the 12 to14
volts, depending on coil 20,,30,,60,000 volts. now what happens if
the secondary windings of these same coils are no longer multipling
12 to 14 volts they are multiplying 500 volts with the box added.
500 volts is roughly 41 times the amount of volts going into the primary
of the coil compaired to just 12 volts.
into the primary, the old round type original coil put out 20,000
volts, some of same type aftermarket round coils with more windings
in the secondary can do say 30,000 volts. by comparison the modern
coils on the LS engines put out 120,000 volts and each one only has
to do the work of firing one cylinder. some of the new e-coils for
old cars 60,000 volts. but no matter the coil, if you
take a coil and the secondary windings are multiplying the 12 to14
volts, depending on coil 20,,30,,60,000 volts. now what happens if
the secondary windings of these same coils are no longer multipling
12 to 14 volts they are multiplying 500 volts with the box added.
500 volts is roughly 41 times the amount of volts going into the primary
of the coil compaired to just 12 volts.
Pro
Joined: Sep 2004
Posts: 595
Likes: 0
From: Boston MA
Hi,
To answer you question. I have a 6al box in my car and I also run Edelbrock Performer RPM heads.
Edelbrock recommends RC12YC Champion plugs, and MSD recommended a gap of .50.
I recently found out that Champion makes the same plug that is already gapped to .50. It is part number RC12YC5 and I have been using those.
Thanks,
Joe
To answer you question. I have a 6al box in my car and I also run Edelbrock Performer RPM heads.
Edelbrock recommends RC12YC Champion plugs, and MSD recommended a gap of .50.
I recently found out that Champion makes the same plug that is already gapped to .50. It is part number RC12YC5 and I have been using those.
Thanks,
Joe
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Safety Car
Joined: Jun 2005
Posts: 3,841
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From: Inver Grove Minnesota
It is hard to keep ones personal comments to ones self when there is a person being so belligerent.
Obviously you are trying to prove something or you wouldn't go to such lengths taking time out of your own life to be a grump to other people that you don't have to meet face to face. So please instead of being like this, explain to us with your wealth of knowledge what we cannot seem to grasp.
To the OP: I run a .50 gap with a msd ecurve and a 6a box. You should be good with somewhere around there since it seems thats what most people run.
To the OP: I run a .50 gap with a msd ecurve and a 6a box. You should be good with somewhere around there since it seems thats what most people run.
Instructor
Joined: Sep 2005
Posts: 241
Likes: 0
From: St Louis Missouri
I run a .060 gap on my Proform HEI. I don't know where I read to do that, but it runs well and the headers are a pain to take off, so I may cut it down to .050 next time they are off.
I too have wondered about the gap of the plug; as I understand V=IR therefore adjusting the gap adjusts R. How much more resistance is .010 air gap I haven’t looked into. If the voltage coming out of the coil is constant then the larger the gap the lower the current. If the current is constant then increasing the gap increases the voltage delivered by the coil. If we make the assumption that the power (P=I^2R or P=V^2/R) delivered remains the constant then the increasing the gap increases the voltage required and decreases the current.
In my opinion if you run a large gap you can expect it to be more taxing on your coil and you may have to replace it sooner then a smaller gap.
I too have wondered about the gap of the plug; as I understand V=IR therefore adjusting the gap adjusts R. How much more resistance is .010 air gap I haven’t looked into. If the voltage coming out of the coil is constant then the larger the gap the lower the current. If the current is constant then increasing the gap increases the voltage delivered by the coil. If we make the assumption that the power (P=I^2R or P=V^2/R) delivered remains the constant then the increasing the gap increases the voltage required and decreases the current.
In my opinion if you run a large gap you can expect it to be more taxing on your coil and you may have to replace it sooner then a smaller gap.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
There are so many factual errors in this post that I don't have the time to correct them all. I sincerely suggest that you read a technical description of how ignition systems work, and you will recognize the many errors you have here. Trust me, your Corvette factory system would not start your engine if it tried to operate as you described.
multiple spark discharge CDI they are all morrons.
Last edited by Little Mouse; Aug 20, 2007 at 10:02 PM.
Tech Contributor
Joined: Jun 2004
Posts: 20,827
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
It is hard to keep ones personal comments to ones self when there is a person being so belligerent.
I am merely asking for some facts to back up all these marketing hype statements. Why is that "being difficult"?
Obviously you are trying to prove something Nope. I don't have the need for other people to validate my thoughts, technical knowledge, or opinions. This is the technical portion of the forum. Why is it so painful for you to back up your claims with some technical information? or you wouldn't go to such lengths taking time out of your own life to be a grump to other people that you don't have to meet face to face. So please instead of being like this, explain to us with your wealth of knowledge what we cannot seem to grasp. I have already mentioned several items in previous posts. What part of those are still unclear?
To the OP: I run a .50 gap with a msd ecurve and a 6a box. You should be good with somewhere around there since it seems thats what most people run.
I am merely asking for some facts to back up all these marketing hype statements. Why is that "being difficult"?
Obviously you are trying to prove something Nope. I don't have the need for other people to validate my thoughts, technical knowledge, or opinions. This is the technical portion of the forum. Why is it so painful for you to back up your claims with some technical information? or you wouldn't go to such lengths taking time out of your own life to be a grump to other people that you don't have to meet face to face. So please instead of being like this, explain to us with your wealth of knowledge what we cannot seem to grasp. I have already mentioned several items in previous posts. What part of those are still unclear?
To the OP: I run a .50 gap with a msd ecurve and a 6a box. You should be good with somewhere around there since it seems thats what most people run.
I have no vested interest if one wants to run a CD or inductive system. When I hear some extraordinary claims about something, I am usually interested in some facts to back up the claims. And so far, I'm not hearing any. If someone wants to say their car runs fine with their system, great. I'm happy for them. But, if you're going to make a technical statement, please back it up. This doesn't seem unreasonable to me.
Tech Contributor
Joined: Jun 2004
Posts: 20,827
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
I have not made any comments regarding the intelligence of people using MSD systems. It's not relevant to the discussion, and I would speculate that there is a wide range of knowledge among users of this product, just like cam buyers, carb buyers, etc. As long as someone is spending their own money on their parts, and are happy with the performance, that's great. I'm merely asking for data to back up some of the extraordinary claims I'm hearing.
(I'm getting tired trying to get this point across.)
ps: Moron is spelled with one r.
Burning Brakes
Joined: Dec 2007
Posts: 952
Likes: 0
I stand by my comment regarding the accuracy of your technical statements.
I have not made any comments regarding the intelligence of people using MSD systems. It's not relevant to the discussion, and I would speculate that there is a wide range of knowledge among users of this product, just like cam buyers, carb buyers, etc. As long as someone is spending their own money on their parts, and are happy with the performance, that's great. I'm merely asking for data to back up some of the extraordinary claims I'm hearing.
(I'm getting tired trying to get this point across.)
ps: Moron is spelled with one r.
I have not made any comments regarding the intelligence of people using MSD systems. It's not relevant to the discussion, and I would speculate that there is a wide range of knowledge among users of this product, just like cam buyers, carb buyers, etc. As long as someone is spending their own money on their parts, and are happy with the performance, that's great. I'm merely asking for data to back up some of the extraordinary claims I'm hearing.
(I'm getting tired trying to get this point across.)
ps: Moron is spelled with one r.
Best place for an MSD box is the trash can.
Racer
Joined: Nov 2007
Posts: 279
Likes: 0
From: Forrest City Ar
I think that it's a theory and you can not prove a theory. I assume that it's MSD position that their 3 sparks at low rpm are better than 1. Eistine ( that may not be spelled correctly ) could not prove his theory of relitivity. All those top fuel & funny cars with the double MSD systems on them are not there because of marketing hype. where is your proof that the statements made above are incorrect. everyone has an opinion. This site is not the IQ bowl there does not have to be one correct answer. Everyone is a winner from the knowledge shared here but back biteing severs no purpose.
Burning Brakes
Joined: Dec 2007
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NASCAR uses CD systems, but uses two, since 1 fails often. They are also NOT the units you buy at Summit.
Tech Contributor
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Racer
Joined: Nov 2007
Posts: 279
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From: Forrest City Ar
I know what magnetoes are ( to some extent ) they produce their own current for one ie don't need battery to run, they are a back up system yes but they also contribute to preformance. if you have ever been in a small plane when the pilot did his runup test you would have noticed an rpm drop when he checked his mags. I don;t know anything about ignition system or engines. my point was that if MDS systems are being used by the big boy their products are sound. my engine builder has 30 yrs exp and that's the system he used. my second point was this is not the place to prove who is the smartest. This fourm is for discussion not a p***** contest.
Racer
Joined: Nov 2007
Posts: 279
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From: Forrest City Ar
Yes I have a 2000 V-Rod and I think it runs on a mag too. I has a stage one screaming egale kit and will hit 60 in !st. I am not trying to pick sides here I just think things got out of hand last night