MSD 44 Grounding ???

My 2 cents

We run a BBC with a Supermag 3 with 3.8 amps running low 7`s / high 6`s. When I read about the grounding issue on this website about a year ago I put the earth leads on the engine. I have a bolt on the engine plate and run earths from both heads and the coil to it. When I put this in place, I did not find a performance gain, but the car became more consistant and it definately cleaned up the idle- it instantly became a LOT smoother.
Cheers.
Jim

 

I use this (see below) strap bolted to each one of my heads and to tabs on my frame. It's just a 2 GA x about 18" long grounding strap. I am running SBC, blown, injected alcohol without a mag. But I found years ago that grounding, or lack of, caused me all kinds of MSD and timing issues.

 

Thank you for that analogy now its all clear to me !!!!!!!!! that has got to be one of the funniest and most distorted replys I have ever read on this forum! lmfao

 

I am not an electrical engineer either, but I do know that supplying a constant current path at 12 volts dc or 120 or 240 ac is a lot different than supplying a current path for a series of 40,000 volt pulses.

When dealing with that kind of situation, then things like capacitience,inductance,harmonics and transients can rear thier heads in wierd and unexpected ways. Another thing to consider is that most of the aluminum used in race cars is not pure aluminum.

Along this same line I have often wondered what the effect of running copper base seals on the plugs with ground wires running to coil ground would have.

Richard Gavle

 

ground/earth

Now that this has been brought back up, I'd just like to add a reminder that PAINT and ANODIZE will NOT transfer a proper ground/earth. Be absolutely sure that these items are sanded CLEAN/RAW before bolting anything together that is expected to carry current. Just because the eyelet is bolted in place does not mean it will work.
Small example: SAE kill switch in anodized dash. Switch body is ground, so dash hole for it must be sanded, then where it bolts to chassis must be sanded, and welded tab on chassis must be sanded.
See if you can guess why I know this.

 

grounding

I have spoken with MSD before about this and although you don't always get the same answer from everyone there they told me in order to be positive about it to ground both heads together as well as the coil, and mag base all to a common ground on the chasis. Never hurts to be sure I guess.

 

Is that for noise reduction, like for data collection reasons?

 

Taken from Nology website,

Nology HotWires are the most technologically advanced ignition wires available. HotWires create the most powerful spark possible. HotWires are engineered with a special built-in capacitor, exclusive only to HotWires. This revolutionary design allows energy from the ignition coil to accumulate in the capacitor until the voltage at the spark plug electrodes reaches the ionization point. At that split second point the entire power of the stored spark is discharged at once, creating a spark 300 times more powerful. The result is faster, more complete combustion, and most importantly,


This approach as TFX has mentioned is the opposite of most current ignitions which strive for either multiple sparks or a single spark of greater duration.

I have always wanted to build a set of plug wires with a braided shield around the outside to supress emp to protect all of the components of the ignition and timing control system as well as any other electronics in the area.

Richard Gavle

 

Good Earth Point

Ooh, yeah, VERY good point Bob. How long did that take you to find?

Richard, are you aware a lot of aircraft use shielding on their leads?

 

thjts,

Yeah absolutely,

To me its amazing how little of it I see on drag cars, about 5 years ago I was running a nitrous car with the crank trigger and was at the track and picked up a single pop when revving the engine in neutral. Well after changing the plugs and going through the air bleeds on the carb to no avail I decided to wrap a piece of 14 gauge copper wire in a spiral around the trigger cable and ground it at both ends () problem solved. I also used a diode on the supply to every solenoid, to ground flyback voltage. For about 2 dollars per coil()solenoid it just seemed to be a good investment. MSD also makes a big capacitor pn 8830 to run on the power supply to absorb rapid voltage change.


Its so easy to engineer these type of systems to supress noise I see no reason not to use them.

 

Noise Suppression

I totally agree.

Shielded cables are available from datalogger manufacturers, and there is plenty of non-automotive shielded cable available as well. With the amount of 'noise' that a magneto puts out, proper grounding and shielding is a must!

I wonder how many racers are out there scratching their heads trying to find out what's wrong, because of poor or no grounding or shielding...

Paul.