I tried to make the best decision for quality and longevity. I couldn't see sending my unit to msd because I didn't feel I would be getting a long-lasting product. Maybe I was wrong. I tried to compare the output of the boxes to get comparable to the msd since I enjoyed the pep it supplied.

I chose the Summit #850611. It seemed a step up from the msd 6a. It was easy to install--once I opened up the distributor and traced the wires, and determined the colors of 40+ year-old wires.

But I was a bit disappointed with the performance. The pep from a stop is not quite there; not quite equal to that of the msd box. I find that surprising since all the numbers, spark, volts, etc., were greater than the msd box, and yet.... But my knowledge of electrical components is limited.

Now that I have tried it, and feel disappointed, I am considering having the msd box rebuilt.

 

F - I'd put a timing light on your engine before I did anything else.
It may be that the new box is delayed a couple degrees.. Shouldn't be, but you won't know until you take a look.. ��

 

Well, I called Summit and spoke to a tech guy. He said to ground to the battery -, which is eight feet of wire away, instead of directly to the frame, two feet of wire from box, as I now have it. I'm skeptical, but okay. He also said to upgrade my coil from the old 1990's msd to a new one to get double the spark. Yeps, 'double the spark.'

BigFoot: Good idea with the timing light. I didn't think of that. Thanks.

 

F-250 restorer, I am sure I am "preaching to the choir", as you are very knowledgeable, but make very certain the two signal wires from the distributor to the ignition box have not been crossed. It makes a huge difference... don't ask me how I know?

 

If using the distributor's pickup as simply an un-amplified hall-effect sensor, this is true!!! The trigger would be on the back edge of the square-wave rather than the front-edge. This will retard timing.

 

Thank you. I'm just a guy with a little knowledge and doing the best he can. I tried to hook it up as stated in the directions and it wouldn't start or even act like it wanted to. The moment I crossed the wires, thinking that somewhere over the years the colors had been changed or just really difficult to tell what they are, it fired right up. However, it does feel as though the timing is retarded.

Now I shall check it again. And the timing too. I forgot to do that today. Thanks guys.

 

This is very interesting. Today I put a timing light on it. I'm showing an advance so great that it is sitting at the edge of the scale, and it wants more advance. And set there it runs sluggish, as though retarded. Starter does not kick.

I had it set at 8* advanced prior to the install.

If I invert the wires (as instructions call for) I have to advance it about 10 degrees just to get it to run. And then the light shows it is at the far end of the retarded scale. Either way I hook up the wires it wants more advance. I'm baffled.

Anyone got a hunch?

 

Do you have the box set for 6 cylinder mode?

 

Lol, it would explain a lot if I didn't, uh? That was the first thing I did. Setting it to 6 cyl mode meant cutting one wire.

 

Hmmmm......
Okay so now I'm wondering about your distributor....
Is it a Duraspark dizzy that you are running as just a Hall effect unit or are you running through an ignition amplifier or ??
I have used Durasparks, but until I braided in a ground wire along with the two HE wires, I had a flakey startup..

 

I have a ground wire on the dist. but the MSD said not to use it since the msd set up was grounded. I suppose it wouldn't hurt to ground it? It is a standard DS2 with the hall sensor--nothing more.

I think I will tinker a bit more, and if I can't sort it out, I'm shipping it back to Summit and am going to refurbish the MSD. Enough. This is supposed to be better than a msd? uh-huh.

 

All in all, I'm disappointed in the Summit box. There only a slight difference over the GM 4 pin module. And is it quite bit below, performance wise, the MSD 6A.

I am sending it back for a refund, and will ship my 6A to MSD for a rebuild.

 

You might want to borrow / try another timing light. I had a Snap-On light that just about crapped itself everytime I hooked it up to a car with an MSD.
Let us know how the refurb works out with MSD.

 

I had that problem when I first got the MSD. I also learned, after tasting the fillings in my teeth, to not touch the #1 wire unless standing on a piece of wood. That mistake ranks right up there with leaving a breaker bar on the v.dampener nut and hitting the starter!

I will let you know how the MSD turns out. Y'know, I just really like the MSD. This unit was supposed to be (by the numbers) a better unit. I'm baffled. Oh well, back to being happy with the MSD.

I'm tempted to try that mopar module I posted about.