Pertronix Electronic Ignition Fitted to a Rover SD1
The car in question is a 1980 SD1. As with most Rovers it suffers from being modified by the uninformed mechanic. Mine left the factory with EFI and solid state ignition. Presently it has a rebuilt points and condenser distributor from a Buick 215 and dual Stromberg CD-175 carburetors.
Before attempting to convert your 3500 engine to solid state ignition it is necessary to obtain the correct conversion kit. There are presently four manufacturers that I am aware of. They are Pertronix, Accel, Mallory and Crane. The technology used varies with each manufacturer. Most use a magnetic proximity sensor. In electronic terms, this is a Hall Effect Sensor. It is an electronic switch that responds to a magnetic field. The magnet is placed over the distributor cam and the sensor replaces the points. One other type available uses a switch that detects a change in the magnetic field. There is no rotating magnet in this type. The sensor is placed close to the existing cam lobes and senses a change as the cam lobe passes. This article will cover the conversion using the Pertronix standard kit. If you are interested in the other systems I would suggest you talk to your local jobber, parts supplier, or check the manufacturer's web sites. There are also various models offered by some of the manufacturers. Pertronix, for instance, also offers a version that claims to give an equal dwell and spark energy independent of engine rpm. Both kits are claimed to install identically.
To my knowledge there are four different distributors that may reside under the hood of your 3500 equipped pride and joy. You may have the Lucas solid state distributor, the Lucas points distributor or as in my case the Buick 215 distributor - you guessed it, ..... points and condenser. There are two versions of the Buick distributor. The kit you use will depend on the type of distributor. The kit manufacturer can help you with the details but you will require the distributor number. This should be cast in the body of the distributor. The Buick distributor may have the advance weights above or below the points and condenser plate. A different kit is required for each. As you can see in the attached photos the distributor in question is the Buick version with later style advance weights above the cam.
It may be a good idea to check the polarity of the coil before removing the points ignition. If your Rover is like mine, I would not trust the repairs of any previous mechanic. To check the polarity, rotate the engine till the points are closed. Do not reattach the distributor cap. Take a DC volts multimeter, set to 20 V. D.C. or more, or use an automotive test light. With the negative meter probe grounded on the chassis touch the positive probe to the coil. With the ignition "ON", the positive probe should read battery voltage (more than 12V). When attached to the negative coil connection the reading should be close to zero. This is only with the ignition points closed. Alternately, the test light can be connected in either polarity. Attaching to the positive side will light the test light, the negative side should not light the lamp once the points are closed. If you get the opposite effect it will be necessary to exchange the position of the factory wires. Do not leave the ignition on any longer than necessary with the points closed.
To install the kit, remove the distributor cap and place to the side. If you want some adventure you could try unplugging the spark plug wires and not marking their location. The first item to be removed and thrown away with a strong overhand motion are the points and condenser. Alternately you may try for a 2 point basket. Remove the rotor. The Pertronix kit includes the magnetic segments inside the black ring assy. If you look closely you will be able to see the magnets as they are red covered with a clear plastic. Other kits may have various magnet styles. This ring will be mounted below the advance weights with the screws mounted upwards through the plate to hold the rotor. Leave loose. Now the sensor assy may be attached to the points and condenser plate using the existing locating holes or peg(s) depending on distributor style. Lock in place with the original screws. Lightly tighten initially only. If the screws took flight during the previous step you will have to start digging. There are two nuts in the kit to hold the magnet assy and the rotor in place. All rotors are keyed for proper positioning. Before attaching the rotor and thereby locking the position of the magnet ring, remove the rotor mounting screws. The studs of the magnet ring will pass though the advance weight plate and the rotor. Tighten the nuts sufficiently to hold the components in place and to not allow movement. Over tightening will at least warp the magnetic ring and at worst strip or break the mounting screws. The other Pertronix kits make use of a magnet ring that is placed over the distributor shaft and under the rotor. For an 8 cylinder engine, the ring is cast with an octagonal recess that fits over the existing distributor lobes. For the Buick distributor with top mounted advance weights, it is necessary to measure the gap between sensor and magnet ring. Pertronix advises that the gap between ring and sensor be 0.010 - 0.060". This is checked by rotating the engine one revolution. This will move the rotor 180 degrees. With the weights and distributor shaft pressed down the clearance should be at least 0.010". Now pull up on the weights and repeat the process. Checking the clearance at various points of turning the engine the gap should be less than 0.060" with the weight up and more than 0.010" with the weight pressed down. There are washers included in the kit to adjust the clearance. The unfortunate detail of the top mounted weight distributor is that adjustment of sensor gap involves repetitions of removing the sensor and the ring to insert the adjusting washers. If the gap is too large after correct adjustment of the minimum gap, the distributor should be removed and the large brass washers in the kit used to reduce the gap between the lower drive gear and the base of the distributor housing. In a distributor without top-mounted weights, the magnet will pass through the center of the sensor on the vertical face. There will be a spec for sensor gap in the installation guide. This style is much easier to adjust correctly. You may want to use a willing volunteer and on the starter. If the car is on level ground pushing it in 3rd gear also works well. When satisfied that the ring and sensor are properly, located tighten each to lock position.
After attaching the sensor and magnet ring, pass the two pickup wires through the distributor housing. These two wires attach to the coil. Before they get there, you will have to pass them through the base (or exit hole) of the distributor. There is a rubber grommet supplied with the kit that will take the place of the original grommet. Ensure that the wires do not rub on the arm of the vacuum advance unit. This shaft will move as the vacuum increases during driving. In fact, now is a good time to check the operation of the vacuum advance. Disconnect the tube from the carburetor and suck on it. You should be able to build up a vacuum. While sealing the tube with your tongue the vacuum should not leak down. Cleaning the tubing is optional. Blackened lips and a black donut ring on the tongue can bring a smile to the better half.
There is an optional coil that promises a 40Kv spark. To my surprise the stock coil in the 1980 SD1 is listed as high output. I have not yet seen the spark on a scope to measure peak voltage. The stock coil however is heavier than the Pertronix coil. The Pertronix solid state conversion kit requires a coil with a 1.5W (ohm) primary coil resistance for 6 & 8 cyl engines and 3W for a 4cyl engine. The stock Lucas coil has the correct resistance. Having said that it, is always better to ensure that your present coil has at least 1.5W. If the coil is not a high voltage coil I would recommend purchasing an upgrading coil. You can check the primary resistance with an ohmmeter. Almost all DC multimeters have this function. It will be necessary to remove all wires from at least one side of the coil. If the resistance measured is less than the required 1.5W you will have to replace the coil or install a ballast resistor in series between the sensor, 12V supply and the coil. The stock SD1 should have a ballast resistor on the inner wheel well. The installation guide of this kit has a good section regarding determining if a ballast resistor is required. Failure to use the proper coil or resistance will void the warranty. I don't know about you but I really object to buying the same part twice. The two wires from the sensor will attach to the coil. The red wire to positive and the black to negative. It is personal choice at this point but I have found it is helpful to solder the connectors and extensions. If proper wire solder is used the connections will last longer than if they are crimped only. Do not use plumbing solder, the acid will corrode the joint and defeat the purpose of soldering. [ed... resin cored solder for electronics] At this point you are ready to have spark.
I would advise checking the static timing before attempting to start the engine. Check the engine tune up specs that apply to your car's year. You will require a right angle wrench to adjust the distributor position. My SD1 uses a 9/16" or 14mm bolt. Re-attach the distributor cap. If the engine will not start at this point refer to the Installation Guide. It is always a good idea to check all connections, position of the distributor cap and installation of sensor. The Pertronix guide has some helpful tips to determine the source of the fault. After the engine has warmed, disconnect the vacuum advance and check ignition timing. Now you should be ready to burn up that highway. Happy Rovering.
First impressions after several days of city and highway use, is that the kit installation has resulted in a smoother running engine, at idle and during acceleration. There is now a power curve where the points and condenser ignition would result in no power above 3000 rpm. I would recommend this conversion to anyone desiring to "throw those points as far as…"
by Ron Morey (Canadian member of The RoverNet)