311s.org Datsun Sports Tech Wiki | TechSection / 311s.org datsun sports tech wiki browse

Published 2007

Electronic Ignition Options.

By Dave Brisco

This is intended to be for general info and does not endorse one product or method over another. First things first, millions of cars have done trillions of miles on points. They work well and are dependable, but require periodic maintenance and more spark power can be obtained with electronics.

As of now, there are three basic ways to add electronic ignition to a 1600 or 2000. Method one is to remove the points and add an electronic triggering mechanism to the original distributor. Method two is to replace the whole distributor with a more modern Nissan EI distributor rebuilt and modified to fit the engine. Method three is a distributor less ignition, which would be a custom built unit. People have done it for Roadsters and could add their comments.

I will outline what I know of the first two and people can decide what fits their needs. MSD and other CD ignition boxes will function with original points, conversion kits or Nissan EI distributor. Same (high) output no matter what triggers the CD box.

Original distributor with a conversion kit This has the advantage of a stock appearance, lower cost and no need for a new coil. The coil still runs on approximately 6-8 volts, and the spark is no stronger than a new set of points, but now the points don’t wear, and the timing and dwell remain the same. Pertronix is one of these systems; Crane also makes the XR-700 which is an optically triggered system with an external control box. There are probably a few others. Up side is low cost, usually $70.00 to $120.00. Pertronix install is very simple, Crane is a bit more involved, more wiring and setup. My Crane has been 100% trouble free, and I haven’t heard any bad Pertronix stories. You can use your stock coil. No routine maintenance required. Some downsides are stock voltage output, and that you are still using the same 40 year old distributor, and if the advance mechanism and or shaft is worn, loose or not lubed, timing will be inaccurate and performance will improve very little. If you have a smog distributor, 68 and later, you would still need to recurved it. My original 69 distributor was a mess inside, rusted, dried grease, and both vacuum and mechanical advance not fully functioning. Of the roadster units I’ve disassembled this week, 80% were gummed up and the advance mostly or totally inoperative. A clean, lubed properly tuned Roadster distributor with an electronic kit is very dependable. Replacement electronic parts, if you were to need them for an after market kit, could be hard to find locally except for carrying an extra kit or a complete points setup as a spare. Crane and Pertronix could be changed back to points roadside, if needed in half an hour if you had the parts with you.

Crane also makes an XR3000, which is similar to the XR700, costs a bit more, but runs full 12 volt to the coil for much more spark, so it’s an in-between option. It requires a new coil, but the same spark output as a 210/310 EI conversion is possible. Again, condition of the Roadster distributor is the key to dependable timing.

The Nissan 210/310 EI conversion This distributor, made by myself and others is slightly larger than stock, and has a control box on the outside of the housing. This is the system Gary Boone used. The ignition coil runs at full battery voltage, almost doubling the voltage into the coil and allowing a wider spark plug gap and larger hotter spark. As with other electronic systems, the timing and dwell remain stable. The larger cap helps prevent crossfire with the new higher output voltage. The other advantages are a clean functioning advance mechanism with a non-smog 15 degree advance curve and common replacement parts, if needed, are available from any Nissan dealer or most parts sources. Installation is straightforward, the entire distributor is replaced, and a new 12 volt coil is required.

Other Nissan units. Someone is selling a Nissan based conversion on Ebay with an internal control unit. I have only seen photos, so I don’t know the specs. It appears similar to the H20 forklift distributor, which I have seen and disassembled. It could also be an earlier 210/1200 unit which used a similar pickup. Same basic look as a stock points distributor, slightly larger cap. I assume if it was set up correctly, it would function as well as any other conversion. The seller gives few details.

MSD and other CD ignitions These capacitive discharge units use a separate control box and can be triggered by any of the above units or stock points. Their output is the same no matter what the triggering method is. If you trigger it with points, the points last a long time, as the current they are switching is very low. A good matching coil is required. Energy is stored in capacitors and a very short high voltage pulse, or a series of pulses, is sent to the coil. Primary coil voltage 300-400 volts. This produces a very high voltage spark when used with the proper coil. MSD and some others produce multiple sparks for more complete combustion up to about 3000RPM and to prevent misfire then one big spark above that. Some have RPM limiters built in, which is a nice option. Read the manufacturers specs before buying. Some of the big names are Crane, Jacobs Mallory, MSD Pertronix and Summit Racing, and I’m sure many others exist.

More details are here http://en.wikipedia.org/wiki/Capacitor_discharge_ignition

I have heard from a few people over the years that MSD’s in particular are known to be dependable and trouble-free for years, and then suddenly fail. If you set up your wiring harness correctly, you can unplug it, put in a jumper plug to bypass the control box and get home. I can make a diagram for anyone’s interested.

Conclusions Whatever you chose, match the rest of the system, spark plugs, plug wires and coil to the distributor. Any system with other than a stock coil should have minimum 8 mm plug wires, and could experiment with wider plug gaps up to and above .040 inches.

Someone once told me 75% of all carburetor problems are actually ignition problems. You definitely know if your ignition is not working, but it is tougher to tell if it’s not working 100% correctly. My personal experience with the Crane XR700 and Crane coil is that the car starts more quickly cold, and requires less use of the choke.