BEWARE msd ignition

[Egoracing]

34 head studs, 16 pushrods,4 head alignment dowels pins, one dizzy.... and no ground path.
Your name Murphy?

None of thise are a good ground path, Especially the distributor. Steel to aluminum will corrode, add power going thru it and you increase the rate it will happen, then if you use a sealer on the bolt threads you are increasing the resistance that the power has to defeat to get to ground and increase the corrosion rate. I am not saying it wold ever happen again BUT it was interesting to find when we did. The funny thing is I have had odder things happen to our cars, I believe Murphy was a racer!

When ever I ground the engine block or heads if it is aluminum I will put an anti corrosion product on the threads that will conduct electricity.

[jedclampit]

Sorry, not possible!

Any decent racing ignition will easily arc a 1/2" air gap.

Some of the stuff you post does have merit..... but this is another impossibility, and some of your stories rival those of the infamous Dynoman.

It Irresponsible to post BS fairy-tales here.

I don't know what you do for a living, but it is obviously not automotive related!

[dualdj1]

Jed,
Believe him or not (i'm not saying one way or another), his statement about grounding the heads and coil to same location still has merit, providing the best possible path for strongest spark. whether or not it's a significant gain, who knows. But if you look at Passenger cars, most of them have a ground strap from the head to the chassis, or the coils mount right to the head.

[ep33510]

BEWARE msd ignition

The process that Ego racing has been doing for his racing program is part of the Balance & Blueprinting process of the ignition system. The goal & results are no different than when you Balance & Blueprint an engine to make sure each cylinder is providing equal & maximum effort out. Yes, there are other ground paths in any racing platform. But to put faith in a motor plate, chassis, engine block /heads & misc. hardware to haul a constant solid electrical ground for racing is not a wise play. Yes, it works for the street and yes it does currently work for some racing applications. But if you’re spending hard earned money to field a car each week and be competitive. Then you’re leaving performance on the table that could be used to fight for the top spots. The reason grounding is so important, any electrical system likes power to be solid and never change. With the MSD boxes an Ok grounding path will cause the MSD box to draw more current which heats them up and drops their energy output. If you want to keep a MSD box happy all night long just keep in mind you want the unit to think it is sitting right next to the power source on a bench at the shop. I know what I am about to say will draw some fire but it goes a long way to making sure your fielding your BEST effort. There should be a ground strap from each Cylinder head to ground. You should have a ground strap from the engine block to a ground point. Any common ground point on the chassis should have a ground cable run from the battery ground lug to it. Never fully rely on the chassis to haul the ground at all times. We have seen way too many have issues over the past three years with private & well-known chassis builders alike that have mechanically sound welded joints but the joints are adding 1 to 5 ohms of resistance or more into the ground path if something is attached to that particular section of the chassis. It may not seem like much but just that little of resistance in the ground path will affect the MSD box and cause other gremlins to pop up. So the whole goal is to make sure that no matter what part of the racing platform you are hooked to, you are attaching to the same ground plane for electronics to work from.

[jedclampit]

Jed,
Believe him or not (i'm not saying one way or another), his statement about grounding the heads and coil to same location still has merit, providing the best possible path for strongest spark. whether or not it's a significant gain, who knows. But if you look at Passenger cars, most of them have a ground strap from the head to the chassis, or the coils mount right to the head.

Production car engines are rubber mounted, and definitely need ground straps.
Sometimes redundant body/ engine ground straps to handle the current draw of power accessories.

I do not doubt that a wired ground is almost foolproof and probably best practice.
We have never used a wired ground on a Late model, and never had an engine ground problem.... in maybe too many years of racing.


An ignition not to have a ground path because of no coolant, sorry, I was born at night.... but not last night!

I'm done with this, but will call bull when I hear it.......again.

[Egoracing]

Production car engines are rubber mounted, and definitely need ground straps.
Sometimes redundant body/ engine ground straps to handle the current draw of power accessories.

I do not doubt that a wired ground is almost foolproof and probably best practice.
We have never used a wired ground on a Late model, and never had an engine ground problem.... in maybe too many years of racing.


An ignition not to have a ground path because of no coolant, sorry, I was born at night.... but not last night!

I'm done with this, but will call bull when I hear it.......again.

Sorry if you do not believe it but I have seen MANY things that I still do not believe that have happened in a racecar. A rollover ball come out of the fitting on a foam filled fuel cell and end up in the pickup tube. A tire go flat and find a body bolt that got punched thru the wheel by the brake rotor. A throttle stick after a caution and not be able to fire to find a small rock stuck between the linkage and carburetor.
As I stated above you are not going to get any electrical conductivity thru the distributor or pushrods and minimal if any thru the dowel pins on the head. So you put a multi layer head gasket, silicone on the intake and thread sealer on the head bolts. Where is the solid metal to metal contact that will make the ground? It would be like running with loose cables on the coil. The MSD will jump 1/2-3/4 of an inch IF it is jumping with a good power feed to a solid negative. Put a 100ohm resistor in there and the gap drops to a 1/4 inch.
As for what I do for a living, I engineer, install and test life safety systems so figuring out circuit load and connective resistance are a daily event.