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Author Topic:   MSD vs. HEI
race33
Dirt Full Roller

Total posts: 51
posted December 08, 2005 07:45 PM  
I have been running an HEI for a while and have had good success. I am moving up a class and built a motor for next season with a lot more horsepower than before. I have had several people suggest that I go to an MSD rather than stick with the HEI. What is involved in the change? Is it the control box, coil, and different distributor? What are your thoughts on the two? What are you guys running?

john56h
Dirt Full Roller

Total posts: 28
posted December 08, 2005 08:19 PM  
The track I run allows MSD ignition and about half of us still run the HEI (with a good coil and module upgrade) and the other half use the MSD. I don't see where they are any faster, but I do notice that the guys with the MSDs seem to fall out of a lot of races and constantly are having trouble with their ignition systems. Even in Nascar they wire the cars up with a spare ignition box on a switch so the driver can go to the backup if he has ignition troubles. That tells me that they are just inherently unreliable. You know that the Cup teams get the absolute best parts that the manufacturers can produce (been Q.C.inspected, tested, etc..) and they still don't trust those ignition boxes.

leftturn29
Dirt Maniac

Total posts: 106
posted December 08, 2005 08:38 PM  
Get a DUI, its well worth the money and easy to set up and use.

Eljojo
Dirt Forum Champ
Total posts: 994
posted December 09, 2005 04:16 AM  
Put a goo coil and a big green MSD module in your HEI----don't EVER let it bite you thru the plug wires.

Donald g man
Dirt Roller

Total posts: 20
posted December 09, 2005 04:37 PM  
MSD is very reliable, all parts can fail at some point in time. NASCAR boys don't run HEI do they? No they run double systems because last place pays $50 thousand or more. We started with a GM HEI with the MSD module three years ago and moved up to the MSD HEI one year after that. The original GM HEI is still going strong in an other car. Look at the stock HEI bushings and shaft after some time and you will find a lot of slop in the shaft which leads to timing issues. The MSD HEI has a sealed bearing system that will out last the upgraded GM HEI. Grounding the block is paramount with any system to reduce voltage fluctuations, and a well charged battery won't hurt either. Check where the gears mesh to verify distributor depth into the manifold so you have full contact with the cam and no excess weight on the oil pump drive shaft.

Steve Dupree
Dirt Freak

Total posts: 372
posted December 09, 2005 05:07 PM  
Everyone has opinions but no matter what you do Don you will never compete with this FORD next year. Marry x-mas See ya Jan.22 and show you how bad this ford is. Be good guys and have fun

Donald g man
Dirt Roller

Total posts: 20
posted December 09, 2005 07:58 PM  
Steve, triks 'r for kids.

racer17j
Dirt Forum Champ
Total posts: 5483
posted December 09, 2005 09:05 PM  
17j, you are correct. I am debating either sticking with the HEI with the MSD coil and module, or go to a completely different setup, consisting of the MSD control box, MSD coil, and new MSD distributor. I actually got hold of one to use tomorrow at our track for practice, so I will let you know how it worked out.

Steve Dupree
Dirt Freak

Total posts: 372
posted December 10, 2005 05:47 PM  
Well i dought you will see a difference but better spark is more HP!!!!!!!!!!! Not going to change a 100.00 item and see a big difference unless you are talking set up with shocks and springs. Spend money wise and fix what needs fixed. My opinion

Donald g man
Dirt Roller

Total posts: 20
posted December 10, 2005 10:52 PM  
Steve you are rite again! What the MSD people told me is the MSD only makes multiple sparks below a few thousand RPM which really helps with a fat mixture in the idle circuit at startup and low RPM, after that it's a good hot single spark. A regular GM ignition takes a primary voltage of 12 and then transforms it up to 7000 or 8000 volts. The msd 6 box takes the 12 and boosts it to 400 plus before the coil with a very steep sine wave and then the coil transformes it up to 40000 volts give or take a volt. The hotter spark is said to ignite more of the fuel mixture quicker inorder to get a more complete burn in the combustion chamber. 7000 rpm has each cyl firing 58.3 times a second. The stock GM HEI starts skipping somewhere in the 5000 RPM range so at least upgrade to a good module, cap and rotor. With all MSD products make sure the wiring is large enough for the increased current and no loose connections.

Donald g man
Dirt Roller

Total posts: 20
posted December 10, 2005 11:02 PM  
Sorry that should read all cyl not each cyl. Each cyl would be 7.2 times a second.

Spi-nex
Dirt Forum Racer

Total posts: 79
posted December 10, 2005 11:50 PM  
Isnt it true HEI is only good up to 4500 RPM?

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Jonathon R. Huston
#81 Factory Stock

Donnie Ross
Dirt Freak

Total posts: 265
posted December 11, 2005 08:06 AM  
no, the hei setup with a good module and coil will crank well past 7000 rpm, the main thing is a good, charged battery, use 10 or 12 guage wire to the ignition and use a seperate switch with ignition only drawing from it.

oceanridge motorsports
Dirt Full Roller

Total posts: 46
posted December 11, 2005 06:22 PM  
The hei is a good setup , but it just doesn't have enough ummff above 5500 , the saturation time is just to long . that is where msd starts to shine . I have run the same coil and module for 2 seasons with no problems , the same cannot be said for my old "stock" hei setup . It is just cheap piece of mind , install and forget it .

redneck racing
Dirt Forum Champ
Total posts: 883
posted December 11, 2005 07:25 PM  
I am running a Mallory Unilite distributor with the MSD blaster coil and the MSD 6a box and have had good luck. Eddie

race33
Dirt Full Roller

Total posts: 51
posted December 11, 2005 08:02 PM  
FYI, we ran the MSD today at practice and the motor ran real strong. It seemed to be strong all through the rpm range. Too bad I blew the tranny going down the front stretch. It hooked real strong out of turn 4 and I broke the tail housing off it. We will keep the MSD in it for now and see how it performs in the future.

PEwaste
Dirt Full Roller

Total posts: 53
posted December 11, 2005 10:23 PM  
We run MSD HEI Exclusivley in our A-Mods, and Moroso Durafire HEI in our B-Mods.

The A-Mods we turn upwards of 9000 RPM and have never had a problem. HEI is a lot easier to diagnose a problem with, and works just as good as a MSD with coil. Less to go wrong. We made the switch 2 years ago and haven't had a single problem, even made MORE hp on the dyno... but I think it's a pretty even feild, only made 3 more HP with the HEI.

Donald g man
Dirt Roller

Total posts: 20
posted December 12, 2005 06:17 AM  
The MSD HEI has all the parts in one place, simple wiring, less weight, and if you keep a spare with plugwires you can change the whole ignition out in a minute or two.

  

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