*** Posted on behalf of Chris Champeau ***
MSD 6AL Installation Guide for Porsche 911 SC
OVERVIEW:
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You will need 2 MSD supplied parts to convert your 911 SC ignition from the Bosch or Perma-Tune Capacitor Discharge Ignition (CDI) system currently installed in your car. The first is a MSD 6AL or 6A. The 6AL is part number 6420 and has a rev limiter along with a few other benefits for not much more money. You will also need a MSD Tachometer Adapter part number 8920 for magnetic pickup distributors, like the one in the Porsche 911 SC. You need the tachometer adapter because the MSD 6AL can fire multiple times below 3000 RPM. The tachometer adapter assists the tachometer to accurately read the signals from the MSD 6AL.
Mounting the MSD 6AL ignition Unit: The hardest part of this project is getting the 6AL unit mounted where the old CDI unit was located before. The MSD 6AL is about double the size of the Bosch or Perma-Tune unit, making it necessary to redesign the mounting points on the aluminum install panel. In my 1979 911 SC I had to relocate my external alternator voltage regulator in order to fit the MSD 6AL on to the aluminum install panel. If your alternator has an internal regulator than you will obviously not need to do this. In some cars, you may have to relocate the rear window heater relay. Before you mount the 6AL unit, you will need to select the quantity of cylinders you wish the MSD unit to fire. Locate a knurled cap on the side of the unit, it will be held on by a single center mounted screw. Remove the cap and cut the red wire loop to select 6-cylinder operation. Replace the cap. However, before cutting, check the MSD install guide, supplied with the unit, to make sure that the wire colors have not changed on your MSD 6AL unit.
Wiring: Before you start removing old parts or doing any wiring, it is always a good idea to disconnect the battery. You can source more than half of the connections required for installing the MSD 6AL ignition from the CDI plug that was used to supply connectivity to your old Bosch or Perma-Tune CDI unit. Enclosed below is an overview of the connections on the CDI plug so that you can find where to connect the wires from the MSD unit to the CDI plug. Both my Euro 911 SC Coupe and my 911 SC Cabriolet had the same wire layout in the CDI plug. However, yours could be different, so pull back the rubber boot on the CDI plug and verify that your connections match the ones in the diagrams. All of the wire connections required to install the MSD 6AL and Tachometer Adapter are detailed later in this document.
Tools Required: Wire ties, drill (to install 6AL to aluminum panel), spade connectors (for plugging in wires to the CDI plug), wire stripers/cutters, metric socket set with wrench, Phillips head screw drivers, and floor jack or lift (for access under the car to attach the constant hot to the starter’s positive side post).
Before You Start the Car After Installation: Make sure you do not have solid core ignition wires. If so replace them. Check spark plug gap. “Experts” range in thought here from leave it stock to widen the gap to .055. The truth lies somewhere in between. Check to make sure your coil is compatible with the MSD ignition from the list supplied with the new ignition unit. Once running, check the timing.
Good luck, I hope this install guide helps answer some questions you may have.
Chris Champeau
Richmond, VA
911@planet2000.com
Download File Attachment for Full Instructions with Images
LEGAL DISCLAIMER: This document and the information contained herein is provided "as is", and I make no express or implied representations or warranties regarding this information. If you choose to make use of any of the information provided in this document, you do so at your own risk.
