locking the distributor?

[AngleT]

I have an MSD (8979) ignition control box that will allow me to program the timing advance curve via the MSD and a laptop rather than the flyweights and springs in the bottom of the distributor. This requires me to "lock" the mechanical advance in the distributor. Anyone have an illustration on how to do this or can explain how they did it? I'm thinking that there is some tack welding involved.

I already have the vacuum advance locked (thanks for the pics Bernice)
http://www.xwebforums.org/showpost.php?p=10486&postcount=3

Now for the flyweights...

 

[jvandyke]

I limited the mechanical advance on a Bosch dizzy with little metal tabs, no welding, that was very specific to that dizzy though. Was fun too.
Not sure that helps much.

 

[Rupunzell]

You can pin the advance weights to the rotor plate. I did this on the LeMons racer. Make sure the pins used cannot work loose. A small amount of rotor movement will remain due to the clearances between the rotor shaft and advance weights, but this is very small and should not cause a problem.

You're welcome on the dizzy mechanical tip.

Bernice

I have an MSD (8979) ignition control box that will allow me to program the timing advance curve via the MSD and a laptop rather than the flyweights and springs in the bottom of the distributor. This requires me to "lock" the mechanical advance in the distributor. Anyone have an illustration on how to do this or can explain how they did it? I'm thinking that there is some tack welding involved.

I already have the vacuum advance locked (thanks for the pics Bernice)
http://www.xwebforums.org/showpost.php?p=10486&postcount=3

Now for the flyweights...

 

[dcioccarelli]

Wiki

http://xwebforums.com/wiki/index.php?title=AdvanceModification

 

[dcioccarelli]

Advance Curve

I have an MSD (8979) ignition control box that will allow me to program the timing advance curve via the MSD and a laptop rather than the flyweights and springs in the bottom of the distributor.

Just out of interest, what are you using as the basis for your advance curve? Did you find one for the stock distributor and start with that or are you just tuning by ear? Does the MSD unit also cater for advance / retard based on engine load (i.e. does it have a vacuum input)? Also, does the unit have any knock sensing input? Just interested...

Cheers,
Dom.

 

[AngleT]

MSD 8979 info

MSD 8979 info

I'll have to take it to a dyno to dial the ignition/cam timing in, but the MSD will do the same functions as the flyweights in the distributor. The difference is that if I want to change the curve any, I don't have to buy new springs or flyweights, take apart the distributor and replace those items, then reassemble/reinstall the distributor and re-time static timing. All I have to do is plug the laptop into the MSD and then point and click.

MSD offers other igniting controllers that offers timing retard based on boost pressures when ruining a turbo or supercharger, but I don't have that one. Vacuum advance for when the car is under load is a non-race function for general fuel economy, generally. Ignition adjustments for racing/high performance are made for maximum power at any load, regardless of the vacuum present.

I already had the MSD 7AL-2 ignition, so the controller was the next step. MSD combined these two items in their MSD 7530T (which is overkill for my car) or the MSD 6530in the 6AL-2 version. Smaller box and cheaper price than buying two boxes. Easier to wire up too, I'm sure.

I haven't hooked the Ignition Controller (8979) up yet, so I'm still not failure with all its functionality. Here is the write-up from the MSD website.

"MSD engineers incorporated the favorite controls of the race-proven Programmable Digital-7 Ignition into an accessory for racers already using an analog MSD Ignition Control with a rev limiter such as the MSD 6AL, SCI-L or 7AL-2.The Controllers are loaded with easy to program adjustments. The Controller lets you adjust the timing of every cylinder, map a complete timing curve, pull timing out during the launch, set rev limits, shift points, start retard and much more. Don’t let all of these functions worry you. MSD developed two very easy ways to program the Controllers. For PC users, MSD offers the Pro-Data+ software or for the non-computer racers, there is a hand-held Programmer Monitor. The Multi-Function Ignition Controllers can be trig­geared with a points/ECU trigger, magnetic pick-up in a distributor or the non-magnetic pick-up of a crank trigger. It must be used with an MSD Ignition Control and can be used on 4, 6 or 8-cylinder engines. Each is supplied with Pro-Data+ software CD, PC harness, vibra­tion mounts, wiring and thorough instructions."