Ignition Controls, MSD 6A
 

I am running with just a coil/distributor right now (Mallory eCoil/Unilite). Is there a significant benefit to adding an ignition control unit like MSDs 6A? Is the 'multi-spark' set-up beneficial for street use, or overkill? Can an MSD 6A be installed in the engine compartment?

Thanks.

Mr Magoo,

I believe the MSD (or other brands of high energy ignitions) is an important component, especially if you are running a radical camshaft and/or high compression. But like with any other bolt-ons, the gains from an MSD ignition are much greater when combined with a suite of other parts. For example, having a magnetic trigger ignition and high energy coil will augment the "box" (unit).

You can install the unit on the passenger shelf (top of the foot box) under the hood. Installation is pretty straight forward and MSD provides a very thorough instruction booklet that shows you how to wire it for various configurations.

A big downfall with the MSD-type ignitions is that you can get stranded if the unit goes bad. There are some here that keep a points distributor in their tool bag just in case (!). Depending on your set-up, there are situations where you don't have an alternative to "wire it up" differently in an emergency. I believe some of the other manufacturers (Crane and Jacobs) have come up with better designs that alleviate this problem...check other units out to make sure and do your homework.

One other consideration you need to be aware of is that some tachometers are not set-up to receive the proper tach signal from an MSD box. They sell a tach adapter to overcome this (about $45-50). I happen to have one for sale if you're interested (I ended up installing it but later learned that I really didn't need it after all). It has zero miles on it.

I'm sure some others will chime in here about the pros/cons of running the MSD and/or other brand high energy ignitions. I like the satisfaction of knowing that I'm always getting a very hot spark, and with the lopey roller camshaft that I'm running I need all the fire I can get.

-Deano

One benefit
 

Is the "soft" rev imiter in the 6AL. It not only protects against over-revs, but also sequentially limits spark to cylinders and allows fire every other time so your cylinders are not flooded with gas.

I belive the first up grade should be in the ignition department you can put in a lumpy cam big carb manifold ect but if your ignition can't fire it you are kind of spining you wheels and not going any place. I kind of like the 6AL it has a rev limiter that can be adjusted in 100 rpm modules in a way that don't hurt the motor.
It can be put in the engine compartment center away from the and as headers I installed mine by the wiper moter in the foot box and as RedB said not all tach work with MSD but for a couple extra $ can be made to.
Ken

Thanks All.

I use the Jacobs Pro Street now as it is a great unit I think. I can just wire around it in a minute if the unit goes bad and not have to make any changes. Also set the rev limiter in 100 RPM increments with a small screwdriver. Two adjustments, one for 1,000 RPMs and one for 100 RPMs I have never used the new MSD unit, but did use older ones and I prefer the Jacobs because of ease of changing in case it goes bad, plus it has a variable resistance coil which lets it put exactly the amount of juice to each cylinder that is needed to make them all fire the same. It measures the resistance to each plug and may put 80K volts to one and 75K volts to another if the resistance is less, hence you get the same combustion from each cylinder. I have disconnected it and ran it just off the coil and distributor. I use an inductive MSD distributor in one car and an Inductive Mallory distributor in the other. When I ran them just off the coil and distributor, I could really feel the power loss and also they loaded up really bad at idle. But I am sure the newer MSDs are just as good with the exception of ease of running if the box goes bad. I used to carry a spare MSD box with me whan I was using them and if one went bad I just disconnected it and put the new one in place.

Ron