Datsun Roadster Forum-311s.org

Does anyone know how to identify a distributor? My 1600 has been desmogged, but I don't know about the distributor. Is there any way to tell whether it's a late or early distributor? Whats the difference anyway? Can I just change the springs, and limit the vacuum advance? I just don't want it to run terrible when I fire it up.

Glenn

From the outside, I don't think there is any visable difference. However if you remove the points plate and take the whole thing apart, you will find the cam on the bottom. You want one that says 7.5 on it. You may or may not need to change the springs to make it work, I swapped the plate and didn't bother with the springs and my car is fine, however I might have gotten lucky. Try it, if it pings, you might have to change the springs, if not cool, and away you go.

Will

Thanks Will. I'll look at it while I have it out.

Glenn

I checked my distributor, and the advance plate has 17.5 on it. I am assuming that this is the right one. I think that the whole engine may have been swapped as the number on the engine doesn't match the one on the cowl tag. The only smog stuff is on the intake and carbs. The heads don't have any injection ports that I can see. I guess I'll get it running and worry about the details later.

Glenn

Nope, you've got a smog advance plate. You multiply the number by two to compute the advance. You can turn yours into a non-smog unit by replacing that plate and maybe the springs, not sure. In the meantime, you should set your timing near TDC, otherwise you risk advancing the timing way too far.

See http://hometown.aol.com/calspeed1/faq1.html for the whole skinny about distributors and how to convert a smog distributor to non-smog specs.

Thanks Adam. I guess I'll look for another distributor.

Glenn

Just converted my "new rebuilt" extra distributor today, really easy. Got the kit from an ebay supplier, springs, weights and the 7.5 center shaft all Nissan parts. Took about 20 minutes for the change. You also get a new point cam, so that's a good thing too. Also added a Crane XR-700 electronic ignition, an MSD6AL and a ridiculously high voltage coil while I was in there. Should be fun, can probably run the spark plug gap around .045!
Also had to clean all the "new" 25 year old grease out of the breaker plate. Those ball bearings are REALLY SMALL, smaller than poppy seeds, but moves nice and smooth now.

Bad news, I think I have the weights in the wrong slots, so I have to open it up and look. Murphy's law, If I check it will be right, if I don't it will be wrong.
See this for info in the FAQ link Adam posted, long slot, heavy spring.

If you want to buy a new one, Might want to go to an electronic.