MSD Ignitions

jackjoh

Jack - KC6NAR
Supporting Member
Location
Riverton, UT
In my experience no. Back in the mid 1960's I was racing a Renault Dauphine and built a MSD (Multiple Spark Distribution) capacitive discharge unit with a high voltage coil and it helped that Renault do 95 MPH in the back straight at Riverside Raceway in California. This type of unit comes standard in all cars today. The best thing you can do for old spark gap distributors is change them over to led or magnetic gap that never needs to be changed, checked, or rebuilt.
 

Silly Willy

Well-Known Member
Location
American Fork Ut
Hmmm so to quote Rustys, "...When you're crawling over rocks or creeping up steep grades, these high power sparks are a huge performance advantage..." so it doesn't help? I'm confused.
 

LT.

Well-Known Member
On a stock motor I would say no. But, I have used them with some good results. I used to race a mud truck in a series here in Northern New Mexico. To get all the power I needed I used a 300 horse shot of nitrous. To get the motor to run well on laughing gas I had to over fuel the motor. While over fueling the motor I used to go through spark plugs at an amazing rate. Once I switched over to the MSD ignition I was able to get a set of plugs to last about half a season. Where as before I was replacing them after every run.

What are you thinking about running it on?

LT.
 

oldbluechevy78

Registered User
Location
Utah, Payson
I put one on my tired 350 small block and it woke it up a bit. I used to not be able to let it idle at all unless i baby set it and played with the peddle all the time until it warmed up but it would die all the time even then. Once i put on the msd it has no problem idling, even in the cold, so i think they work, just my 2 cents.
 

bobdog

4x4 Addict!
Location
Sandy
I run a MSD 6A box and a billet distributor (the one that needs the box to run). I noticed a difference, and I would use them again.
 

MikeGyver

UtahWeld.com
Location
Arem
Does it actually show a noticeable difference, and are they worth the price companies are asking for them?

On certain vehicles, absolutely. My MSD 6a was only $140 new. On my turbocharged Camaro I had to close my spark gap off to .020" to (mostly) get the spark from blowing out under boost. With the the MSD ignition, it has no issues at .035" at 6krpm.
They are capacitive discharge and and offer somewhat of a 'continuous' spark as opposed to the single shot the stock ignitions give, they can eliminate misfires and such.
 
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Silly Willy

Well-Known Member
Location
American Fork Ut
On certain vehicles, absolutely. My MSD 6a was only $140 new. On my turbocharged Camaro I had to close my spark gap off to .020" to (mostly) get the spark from blowing out under boost. With the the MSD ignition, it has no issues at .035" at 6krpm.
They are capacitive discharge and and offer somewhat of a 'continuous' spark as opposed to the single shot the stock ignitions give, they can eliminate misfires and such.

Okay cool that answers my question. Now how exactly does it hook up and what other things would I need to hook this up using the available stuff here. http://rustysoffroad.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=rustys&Category_Code=MSD
Or do I just need the MSD ignition box?

Probably sounds like a dumb question, I've never used with one of these and don't want to get part not knowing I needed other components.
 

MikeGyver

UtahWeld.com
Location
Arem
Okay cool that answers my question. Now how exactly does it hook up and what other things would I need to hook this up using the available stuff here. http://rustysoffroad.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=rustys&Category_Code=MSD
Or do I just need the MSD ignition box?

Probably sounds like a dumb question, I've never used with one of these and don't want to get part not knowing I needed other components.

Basically they just see the signal from the ignition control module/points/whatever that fires the coil, and the box fires the coil instead. You'll need to go to MSD's website and look up the install manual, it shows how you connect it to most types of ignition systems.
 

Silly Willy

Well-Known Member
Location
American Fork Ut
Basically they just see the signal from the ignition control module/points/whatever that fires the coil, and the box fires the coil instead. You'll need to go to MSD's website and look up the install manual, it shows how you connect it to most types of ignition systems.

Didn't think of that. Thank you for the advice.
 

Jay5.9L

...I just filled the cup.
Location
Riverton
FWIW I had a jacobs ignition box on my 90 XJ and really could not tell a difference. The stock XJ system seems to do pretty well.
 

waynehartwig

www.jeeperman.com
Location
Mead, WA
You can probably find them cheaper at Summit Racing ;)

Yes, they work. On a street rig you may not notice a difference, but in a high perf application you sure will. But even in a street rig, you might notice better fuel economy. It's all about a more complete burn of the fuel via hotter and multiple sparks.

CD systems not only deliver a hotter spark, but also multiple sparks, which ignites the charge multiple times.

But where it really shines is in the upper RPM's. A stock coil just can't saturate fast enough, so the more RPM's the lower the voltage actually goes. Where the MSD can saturate it'self way faster, thus maintaining the high voltage at higher RPM's better. That's why magneto's are popular. The faster they spin, the higher the voltage they create and they don't actually have a cut off or max like a coil does.
 

Silly Willy

Well-Known Member
Location
American Fork Ut
But where it really shines is in the upper RPM's. A stock coil just can't saturate fast enough, so the more RPM's the lower the voltage actually goes. Where the MSD can saturate it'self way faster, thus maintaining the high voltage at higher RPM's better. That's why magneto's are popular. The faster they spin, the higher the voltage they create and they don't actually have a cut off or max like a coil does.

Very Nice to hear. Now I know when I rebuild my I6 I will be adding one. (I know most everyone here hated the I6 but it has really grown on me :))
 
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