MSD 6AL 6420 Issue?
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
Electronics fail from time to time. Nothing is bulletproof. The Pros have a lot of money invested, besides, I would say what they do is rough duty, Hey, you have your opinion, and I have mine.
Last edited by Mrvettenick; Jul 25, 2020 at 10:59 AM.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
most pro circletrack & roadrace cars w/ big V8 AND that ran carbs & MSD distributors w/ MSD Boxes also ran a redundant system. Crane similar.
One dual pickup aka dual trigger distributor
Two CD boxes that're "Single Action Only" & Selectable (b1 & b2: helps when one of em pukes)
Two Coils that're also "Single Action Only" but are Automatically Selected via One MSD 8210 https://www.holley.com/products/igni...ies/parts/8210
One dual pickup aka dual trigger distributor
Two CD boxes that're "Single Action Only" & Selectable (b1 & b2: helps when one of em pukes)
Two Coils that're also "Single Action Only" but are Automatically Selected via One MSD 8210 https://www.holley.com/products/igni...ies/parts/8210
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
If you want to use an MSD box, by all means.
If you would like an informed opinion, have an open mind.
If you insist on it must be good, everyone uses them, then on that line of thinking:
Ever heard the saying, "Eat ****. 50 million flies can't be wrong?."
Those boxes do make a car idle smoother. No one is disputing that. But reliability suffers. Who idles around town?
If you would like an informed opinion, have an open mind.
If you insist on it must be good, everyone uses them, then on that line of thinking:
Ever heard the saying, "Eat ****. 50 million flies can't be wrong?."
Those boxes do make a car idle smoother. No one is disputing that. But reliability suffers. Who idles around town?
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
That usually prevents failure.
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Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
I will toss this out there as real world experience:
1) Years ago, we had a member since passed named San Diego Paul.
Lars knew him. He hosted a "Tuning for beers tour."
A year or two after that, I came down and spent the day with Paul. He started his vette, and it was the smoothest idling car I ever heard.
However, after idling for about 5 minutes, it would just "blip" once and awhile.
It was driving poor Paul ape ****.
I told him "Change the box."
NOT the box. It's God's gift to hot rodding. Okay. Whatever.
Two weeks later I get a call. He bought a new box. Issue solved.
2) A close friend is having an issue with ignition. It just seemed funny.
I took my MSD box tester over, and we ran a test. Now you know, the multiple spark crap stops at 3000?RPM.
So we hook it up. RIGHT at the transition from multiple spark to single spark, it broke up.
That was freeway cruising speed for that car. Drove him nutz.
So new box, issue solved.
So, just saying, they have their own issues and symptoms. I like reliability, and for me, they just are not.
1) Years ago, we had a member since passed named San Diego Paul.
Lars knew him. He hosted a "Tuning for beers tour."
A year or two after that, I came down and spent the day with Paul. He started his vette, and it was the smoothest idling car I ever heard.
However, after idling for about 5 minutes, it would just "blip" once and awhile.
It was driving poor Paul ape ****.
I told him "Change the box."
NOT the box. It's God's gift to hot rodding. Okay. Whatever.
Two weeks later I get a call. He bought a new box. Issue solved.
2) A close friend is having an issue with ignition. It just seemed funny.
I took my MSD box tester over, and we ran a test. Now you know, the multiple spark crap stops at 3000?RPM.
So we hook it up. RIGHT at the transition from multiple spark to single spark, it broke up.
That was freeway cruising speed for that car. Drove him nutz.
So new box, issue solved.
So, just saying, they have their own issues and symptoms. I like reliability, and for me, they just are not.
Burning Brakes
Joined: Jun 2020
Posts: 881
Likes: 113
Top endurance ranks' motor failures are quite rare; nonetheless, their motors are Not selectable.
When their motor fails, it's obvious & thousands know it; but
but when a selectable box fails, driver simply switches to a backup & no one notices it ('specially when box mfr has a decal on that car)
And as above, the pro teams' cd boxes have been massaged & are more robust than OTS stuff.
e.g. http://www.nelsonspecialties.com/
nick, I hope you have continued good service; and good luck as well
When their motor fails, it's obvious & thousands know it; but
but when a selectable box fails, driver simply switches to a backup & no one notices it ('specially when box mfr has a decal on that car)
And as above, the pro teams' cd boxes have been massaged & are more robust than OTS stuff.
e.g. http://www.nelsonspecialties.com/
nick, I hope you have continued good service; and good luck as well
Le Mans Master
Joined: Mar 2004
Posts: 7,477
Likes: 1,495
From: Little Rock AR
Just some gas for the fire.....Professional racers are not running points. Even though points are supposed to be very reliable....supposed to be more reliable than a MSD.... but those hard headed professional racers with huge piles of money on the line who do demand reliability...insist on running those silly old MSD boxes??? RPM limits I know, but still....
Truth - I have never owned anything from MSD but I do have a 20 something year old Crane box on one car. It was primary current triggered by 1 set of points for many years (never needed any service, dwell settings or points replacements) but I recently went back to a magnetic trigger and will not go back. It idles better and starts easier too. I have more confidence in my ignition RPM than I have in my valve train limits.
LOTS of stuff breaks down on these old cars but still we drive them,
Truth - I have never owned anything from MSD but I do have a 20 something year old Crane box on one car. It was primary current triggered by 1 set of points for many years (never needed any service, dwell settings or points replacements) but I recently went back to a magnetic trigger and will not go back. It idles better and starts easier too. I have more confidence in my ignition RPM than I have in my valve train limits.
LOTS of stuff breaks down on these old cars but still we drive them,
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
Top endurance ranks' motor failures are quite rare; nonetheless, their motors are Not selectable.
When their motor fails, it's obvious & thousands know it; but
but when a selectable box fails, driver simply switches to a backup & no one notices it ('specially when box mfr has a decal on that car)
And as above, the pro teams' cd boxes have been massaged & are more robust than OTS stuff.
e.g. http://www.nelsonspecialties.com/
nick, I hope you have continued good service; and good luck as well
When their motor fails, it's obvious & thousands know it; but
but when a selectable box fails, driver simply switches to a backup & no one notices it ('specially when box mfr has a decal on that car)
And as above, the pro teams' cd boxes have been massaged & are more robust than OTS stuff.
e.g. http://www.nelsonspecialties.com/
nick, I hope you have continued good service; and good luck as well
I guess it's all about comfort level. Hey, how many people you know think Corvettes are over over priced POS?
I'm sure you've questioned the Corvette engineers many times by saying "Why did they do it that way?"
Everyone has an opinion based on personal experience.
Last edited by Mrvettenick; Jul 25, 2020 at 01:03 PM.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Just some gas for the fire.....Professional racers are not running points. Even though points are supposed to be very reliable....supposed to be more reliable than a MSD.... but those hard headed professional racers with huge piles of money on the line who do demand reliability...insist on running those silly old MSD boxes??? RPM limits I know, but still....
Truth - I have never owned anything from MSD but I do have a 20 something year old Crane box on one car. It was primary current triggered by 1 set of points for many years (never needed any service, dwell settings or points replacements) but I recently went back to a magnetic trigger and will not go back. It idles better and starts easier too. I have more confidence in my ignition RPM than I have in my valve train limits.
LOTS of stuff breaks down on these old cars but still we drive them,
Truth - I have never owned anything from MSD but I do have a 20 something year old Crane box on one car. It was primary current triggered by 1 set of points for many years (never needed any service, dwell settings or points replacements) but I recently went back to a magnetic trigger and will not go back. It idles better and starts easier too. I have more confidence in my ignition RPM than I have in my valve train limits.
LOTS of stuff breaks down on these old cars but still we drive them,
I have points on my Model T. Thats enough.
Tech Contributor
Joined: Jun 2004
Posts: 20,868
Likes: 961
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
From my MSD 6530 digital box manual: "The MSD Programmable 6AL-2 Ignition Control will operate on any negative ground, 12 volt electrical
system with a distributor. The MSD can be used with 16 volt batteries and can withstand a momentary
24 volts in case of jump starts. The Ignitions will deliver full voltage with a supply of 9-18 volts and
will operate with a supply voltage as low as five volts."
What are the HEI specs for comparison?
system with a distributor. The MSD can be used with 16 volt batteries and can withstand a momentary
24 volts in case of jump starts. The Ignitions will deliver full voltage with a supply of 9-18 volts and
will operate with a supply voltage as low as five volts."
What are the HEI specs for comparison?
Tech Contributor
Joined: Jun 2004
Posts: 20,868
Likes: 961
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
So does your VE. You don't need as much voltage to jump the plugs above your VE/torque peak (that's why a points system keeps all those 327s firing just fine at 7000 RPM). The reduced voltage requirement allows the spark duration to remain sufficiently long for smooth operation.