What Does an MSD Ignition Do For You?
MSD ignition systems were first recommended to me by a Simon of Real Steel in the UK as a way to solve fuel combustion issues due to the low octane counts which are found in European pump gas. The result would also improve performance. That is exactly what I got !!
The MSD ignition systems combine the concept of capacitive discharge ignition (made popular in the late 60’s and early 70’s) with multiple spark discharge. On a simple point and coil ignition system, while the points are closed, the coil builds up a magnetic field in its core by allowing current to flow at battery voltage into the coil wires which are wrapped around the ferric core, like an electro-magnet. When the points open, the magnetic field in the core of the coil collapses and rapidly introduces a strong, high voltage current into the output side of the coil, which becomes your plug spark. As RPM goes up, the charge time of the coil between sparks goes down, as a result, the spark energy is lower as RPM increases. Capacitive discharge solves this problem by providing a very quick higher voltage charge to the primary side of the coil which is the same at all RPM levels.
Multiple Spark Discharge helps to provide complete combustion at speeds up to 3000 RPM by issuing several sparks during each combustion stroke. The number of sparks varies, but fills up 20 degrees of crank rotation. Above 3000 RPM, there is not enough time for multiple sparks, so the MSD sy! stems then provide a single high power spark. The result of multiple sparks is easier starting, smoother idling, and smooth, crisp, powerful acceleration. An added bonus of more complete ignition is cleaner emissions.
Which MSD Box to Pick:
MSD produces quite a few multiple spark ignition systems. The “6” Series seems to be most widely used . The models in this series include units with and without “soft touch” rev limiters, which keep you from over reving your engine. The rev limit is set either by a plug in “pill” with a designated rev limit, or an external adjustable control. Some units include shock mounts. Other units are available to meet NASCAR specs, to provide spark retard as turbo boost pressure increases on turbo cars, or to provide mult! i-step retards and rev limits for cars using nitrous oxide systems. All Series 6 units are “legal to sell, distribute, or install on non-OBD II vehicles in California according to Executive Order E.O. D-40-2 and legal in all 50 states.
Other Parts You Need:
Most 60’s and 70’s Pontiacs have tachometers in the instrument panels which do not understand multiple sparks. The good news is that MSD sells a “tach adapter”, part number 8910. There is no way around this. Just order it when you order your MSD 6 unit.
If you have decided to get an MSD unit which uses rev limiter modules (a.k.a. “pills”), you will need to order the appropriate pill. The Series 6 units come with pills for 3000, 6000, 7000, and 8000 RPM. The kit of five pills from 5100 to 5900 RPM, in 200 RPM steps, is part number 87451, from 5000 to 5800, in 200 RPM steps, is p/n 8745. Sorry, but they are only sold in these kits of five.
This is also the time to upgrade your spark wires. The sparks from an MSD system in addition to being more numerous, are much hotter. Quality 8mm spiral wound wires work well. MSD makes a set of universal “Heli-Core” wires that you cut to fit. While you are shopping, pick up some di-electric silicone grease for the spark wires and some plug wire spacers. Mr. Gasket makes a set of nice looking blue plastic spacers that cost only a few dollars !
Buy a new set of plugs. You can consider a plug one step cooler for use with the MSD system.
You may also want to invest in a new coil at this point. The MSD “Blaster 2” coil is a perfect match with the MSD systems. Other coils like the Accel Super coil will also work fine but the best results are easily apparent on a full MSD system.
While you are at it, you should go ahead and replace your points and condensor (for the last time), cap and rotor.
Finally, you will need two crimp-on ring terminals: 12 gauge wire, 1/4″ hole, to attach to the battery connections after you trim them. Also, one or two 1/4″ cable clamps are useful to tie down the magnetic pickup wire (which you do not use, but should not cut off) and main harness. All other jumpers, hardware, connectors, etc. you will need are included with the Series 6 kit.
Where to Mount It?
This seems to be a subject of personal taste, but I will submit that having the shortest wires is a sound objective in selecting a mounting location for MSD unit. To this end, mounting on the firewall, under the front window, on the passenger side keeps all wires nice and short. As an added bonus, when you open the engine lid, people notice your investment in an MSD unit…
While mounting the unit, secure the two wires coming out to the unit. The short wire harness, used for magnetic triggering and not by you, can be turned under the unit and tied off with a wire clamp sharing the lower left mounting screw. The long wire harness, which goes down to the coil, can similarly be secured at the lower right mounting screw.
Power Connections:
NOTE: Disconnect battery ground while installing MSD unit. The heavy red wire should be connected directly to your positive battery terminal connector. I found the best place to connect the heavy black ground wire was the chassis lug! located behind the battery, where the battery ground strap connects. A disconnect on the ground lug of the battery is handy to have. In both cases, dress the wires neatly and cut them to length, replacing the lugs with new crimp-on terminals.
Other Connections:
The wiring of the MSD unit is well illustrated in the excellent manual which accompanies the unit, but for the record:
Red wire: Red wire formerly on + side of coil Also connect to one side of 8910 tach adapter (use splicer in kit to attach directly to red wire)
Black wire: – side of coil
Orange wire: + side of coil
White wire: (green) wire from points, wire from tach (black/purple). (You can fashion a one to two wire adapter or use a splice co! nnector here) Also connect other side of 8910 tach adapter (use splicer in kit to attach directly to white wire)
When attaching these wires, I recommend sticking with the connectors already in place and using jumpers to make the female-to-female connections. In the event of an unlikely failure of the MSD unit, it is a trivial matter to drop back to standard spark but reconnecting the red coil wire (+), green point wire (-), and black/purple tach wire (-) back onto the coil and drive off.
Set Plug Gap, Connections, and Points:
Install your new points and go ahead and set the dwell angle with the old ignition system.
As noted in the MSD installation manual, the gap on your spark plugs should be increased well beyond the normal .028″ to around ! .050″. My spark plug gap tool only goes to .040″ and that seems to work, but you should experiment with gaps up to .060″ in .005″ increments. Install the new plug tops to match your new spark plug wires too before you reinstall the plugs. Do not over-torque your plugs and ruin your day…
Installing New Spark Cables:
If you are installing new spark cables at this time (and you should), follow the cutting an crimping directions in the kit.
Spark plug cables should have good separation, not cross, and stay away from all metal. The use of a few wire spacers are helpful here. New wires are pretty firm and stand up on their own with the wire spacers holding them together/apart.
Install MSD Iginition Decal on Tool Box and Go Drive Car…