MSD 6A digital.
Thread Starter
Le Mans Master
Joined: Oct 2010
Posts: 6,900
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
MSD 6A digital.
I just got an MSD box and installed it. I haven't installed one in about 35 years. On an HEI it's almost plug and play.the new digital box has one big plug. So I mounted the box and left the plug free of the box.the instructions say to disconnect the battery which I didn't do I just wired it up and plugged it in and it worked perfectly as I thought,except the battery was slam dead for some reason.msd says disconnect the battery Yada Yada yada, well, I unplugged the box and put a battery charger on it and guess what, it worked perfectly,no.suprise to me.
I didn't expect any power increase, that's not how these things work but I recently installed a pretty hefty cam and it does seem to make it idle a little better without loading up nearly as much and it does seem like it helped ar higher RPM .I'm not saying everyone needs one, but I think the HEI isn't really suited for much over 9-1 compression it's starting to struggle and. About 400 RPM it gets a bit weak. It really was designed for weak smog motors and not a high performance ignition. I'm sure somebody will banter on about it. But I'm very pleased.
I didn't expect any power increase, that's not how these things work but I recently installed a pretty hefty cam and it does seem to make it idle a little better without loading up nearly as much and it does seem like it helped ar higher RPM .I'm not saying everyone needs one, but I think the HEI isn't really suited for much over 9-1 compression it's starting to struggle and. About 400 RPM it gets a bit weak. It really was designed for weak smog motors and not a high performance ignition. I'm sure somebody will banter on about it. But I'm very pleased.
Le Mans Master
Joined: Dec 2006
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As Jackson stated, MSD is useful at idle for engines operating abnormally "fat."
Above 3500 RPM, it does jack ****.That is when it "bypasses." I have observed misses at this transition.
The only other car I can think of that used multi spark was the Model T Ford. Quite useful back when gasoline was horrible.
I do not believe any automobile manufactured in the world uses that tech.
HEI works just fine at higher compression. Coil packs eliminated the "dwell/coil saturation" issue.
Above 3500 RPM, it does jack ****.That is when it "bypasses." I have observed misses at this transition.
The only other car I can think of that used multi spark was the Model T Ford. Quite useful back when gasoline was horrible.
I do not believe any automobile manufactured in the world uses that tech.
HEI works just fine at higher compression. Coil packs eliminated the "dwell/coil saturation" issue.
Thread Starter
Le Mans Master
Joined: Oct 2010
Posts: 6,900
Likes: 833
From: melbourne florida
2023 C3 of the Year Finalist - Modified
The multi spark only works to about 3k RPM's after that it's a capacitive discharge ignition.your right no auto manufacturer uses it because they have a coil on every plug.. they aren't dealing with an ignition designed in the mid 70',s. I see lots of MSD boxes at the drag strip and on some pretty fast street cars, I don't suspect it's because we are all stupid.
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I've got he 6AL digital as well. It works great!!
Le Mans Master
Joined: Dec 2006
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The multi spark only works to about 3k RPM's after that it's a capacitive discharge ignition.your right no auto manufacturer uses it because they have a coil on every plug.. they aren't dealing with an ignition designed in the mid 70',s. I see lots of MSD boxes at the drag strip and on some pretty fast street cars, I don't suspect it's because we are all stupid.
Everything is a trade off in electrical.
Spark "Energy" is the key.
The only ignition that gets "hotter" with speed is a magneto. Check your drag cars again. They all run 2., just like an airplane.
Like an airplane, failure is not a good thing.(Crash/explode).
NASCAR uses them for fat mixtures at low speeds. (Notice, there are always two. They are also NOT your box at Summit. Hand made.
Will they work on a street car. Absolutely. Are they reliable? Well.............
All these speed part people are all corporate owned. Hype is king. Read a 1919 Western Auto Catalogue, still in print, and you will find the "soup de jour" speed parts of the 20's.
The Kettering design is really old, and sometimes it's improved, but always uses inductors.
Inductors, (transformers), out live Caps . Reliable, steady, repeatable, results. It's just how it is.
Rambling over. I could go on 2 hours on the right day,.
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Le Mans Master
Joined: Dec 2006
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Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Le Mans Master
Joined: Dec 2006
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I want to spew one more thing.
I am a retired electrician. NOT an engineer.
My father was a Chief in the Navy.
He was an aviation ignition specialist. Worked on corsairs and such, and taught aviation ignition on a secret Naval Base in Enid Oklahoma.
I still have his teaching notes. He taught me at age 13.
I just have a different "skew" on ignition designs.
They are just reusable blasting caps. (Wait for that rebuttal).LOL
I am a retired electrician. NOT an engineer.
My father was a Chief in the Navy.
He was an aviation ignition specialist. Worked on corsairs and such, and taught aviation ignition on a secret Naval Base in Enid Oklahoma.
I still have his teaching notes. He taught me at age 13.
I just have a different "skew" on ignition designs.
They are just reusable blasting caps. (Wait for that rebuttal).LOL
Thread Starter
Le Mans Master
Joined: Oct 2010
Posts: 6,900
Likes: 833
From: melbourne florida
2023 C3 of the Year Finalist - Modified
I want to spew one more thing.
I am a retired electrician. NOT an engineer.
My father was a Chief in the Navy.
He was an aviation ignition specialist. Worked on corsairs and such, and taught aviation ignition on a secret Naval Base in Enid Oklahoma.
I still have his teaching notes. He taught me at age 13.
I just have a different "skew" on ignition designs.
They are just reusable blasting caps. (Wait for that rebuttal).LOL
I am a retired electrician. NOT an engineer.
My father was a Chief in the Navy.
He was an aviation ignition specialist. Worked on corsairs and such, and taught aviation ignition on a secret Naval Base in Enid Oklahoma.
I still have his teaching notes. He taught me at age 13.
I just have a different "skew" on ignition designs.
They are just reusable blasting caps. (Wait for that rebuttal).LOL
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,027
I worked out there once on top of their water tower in a light rain. NOT fun at all. About 1984 or so.
Le Mans Master
Joined: Mar 2004
Posts: 7,423
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From: Little Rock AR
That new cam has a good bit of overlap event from the 110 lobe separation angle and quick ramps. The extra help from the ignition will make it start easier and idle cleaner/better. Improvement enough there.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Funny ... I KNOW a couple sandlappers who worked w/ South Coast Electric during Wendy's big SoCal expansion
Le Mans Master
Joined: Apr 2006
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Lol sounds like the HEI with no more coil help cant even get the job done at idle much less 4000 rpm or high compression engines It did not get used on. Lol. Corporate giant that its stock went to 85 cents and government receivership from making bad products and its customers simply went to Japan for there cars. Lol I could have bought a lot of that 85 cent stock and been a bit on the rich side today after the government got rid of there people and put others in charge of gm. Italian corporate giant fiat bought chrysler.
Last edited by Little Mouse; Apr 11, 2020 at 10:55 AM.
