Crazy Idea for 280ZX Distributor repair.

[Walter Moore]

I purchased a 280ZX distributor to begin tinkering with with the intention of eventually putting it on my car. I disassembled it yesterday and when I took the "breaker plate" or advance plate whatever you call it out several small plastic pieces fell out of the thing. (The 79' FSM calls it a breaker plate but others here seem to prefer the term advance plate.)

The plate was so jammed up that the top part would not move relative to the bottom part. I also noticed that the magnet that fits under the stator is completely shattered and apparently they are NLA according to this thread:

http://www.classiczcars.com/forums/showthread.php?t=32769&highlight=280ZX+distributor

The plastic it turns out was the final remains of the retainer for the ball bearings that fit between the upper and lower plate. I ended up taking the entire plate assembly apart to get it freed up.

Anyway, on to my wacky idea:

I managed to scavenge some ball bearings the correct size from another junk distributor. What if I took some JB-Weld and attached some washers to the bottom side of the upper wear plate and used them to retain the ball bearings? (See attached picture.) Since the old bearing retainer is shot, (See the broken plastic pieces in the same picture.) would washers glued or braised to the upper slide piece serve the same function?

My only other options are to either lock the two pieces together and forget about the vacuum advance, or to try to run it without the bearings, which would lower the stator by about 5/32" and I am not sure how well that would work.

Also, has anyone successfully made a replacement magnet for this type of distributor from refrigerator magnet stock? It looks possible, but I don't know if it would be strong enough.

[d240zx2]

I think you've got a piece of junk, Walter. If you were to try to make a bearing race out of JB Weld, you'd have to have some sort of release agent to coat the balls with. Not to mention getting the race built exactly to diameter and bearing spacing. I think I'd look at another dizzy rather than spend the time trying to make parts....

Just my 2 cents....

Frank

[jmortensen]

I think you misunderstood what he wants to do. He wants to JB weld the WASHERS to the breaker plate and they will trap the ball bearings. I think it's a good idea, even if I'd just JB weld the breaker plate and run without vacuum advance.

[Walter Moore]

I think you've got a piece of junk, Walter...

:classic: Yep, I suspect that by definition a used part, taken off of a 30 year old car, that was in a JUNK YARD is a piece of junk. That is why I took it apart to see what I had. I also believe that the car was not junked because of the distributor, and that if I had just installed it on the car without checking it out the car would have run, perhaps not well, but it would have worked sort-of.

(It is hard to be sarcastic in writing without appearing angry, which I am not.)

Seriously however, from the appearance of the material used in the ball bearing retainer, I do not see how there could be many of these distributors left in truly "Good" condition. That has to be about the cheapest plastic I have ever seen used in a critical application.

... I think it's a good idea, even if I'd just JB weld the breaker plate and run without vacuum advance.

That would be plan B! If I can't repair the vacuum advance operation I may set it up to run without it.

If people really think that this could work, I may try it and then spend a long time "bench testing" it before trying to install it in the car. The point distributor is working really well at the moment, so there is no overriding hurry to get this done. I think the hard part will be getting the plates clean enough for the JB weld to stick.

I may also see if I can limit the vacuum advance travel somehow before I install it. So many things to play with. So little time...

I will keep you appraised of my progress.

[280~Master]

I believe you can still get most of these part numbers from the local Nissan Dealer.

I have looked into this type of repair and the costs of it.

From what I gather you can get the parts seperatly but not in a kit.

Breaker plate: 22136-H9501

Pickup coil: 22229-Q1700

Magnet: 22158-S6700

Stator: 22163-Q1700

[jmortensen]

Just in case you haven't seen me post it before: http://www.jrdemers.com/280ZX/distributor/distributor.html has a good bit on checking the bushings, rebuilding this distributor, etc.

The breaker plate is pretty smooth. You'll need to rough it up for the JB weld to stick.

[Walter Moore]

I believe you can still get most of these part numbers from the local Nissan Dealer.

I have looked into this type of repair and the costs of it.

From what I gather you can get the parts seperatly but not in a kit.

Breaker plate: 22136-H9501

Pickup coil: 22229-Q1700

Magnet: 22158-S6700

Stator: 22163-Q1700

Thanks! I was hoping that someone would post those numbers. The local Nissan dealer said they were still available. The breaker plate is over $80! :eek:

Just in case you haven't seen me post it before: http://www.jrdemers.com/280ZX/distributor/distributor.html has a good bit on checking the bushings, rebuilding this distributor, etc.

The breaker plate is pretty smooth. You'll need to rough it up for the JB weld to stick.

Great link! By the way, the breaker plate has three spring steel wear plates as part of the assembly, and they are very smooth (and hard). Sometime this week I will try the JB weld, and let you know how that turns out.

[barby27]

How funny is this. Last week I took mine apart because my advance plate was also broken. Many years ago I replaced one on my first 280Z and back then you could get the assembly very cheap. I started to look for another one last week and have been coming up empty. I finally talked to Oliver of ZSpecialties and found that he could get them from Nissan Japan but the price was $129. Currently he is searching to see if any US company that rebuilds these can sell the plate separately. Another thought is to make a CAD drawing of that part and go around and see what it will cost to have them made again.

Lee

http://s38.photobucket.com/albums/e106/babry27/77%20Datsun%20Restoration/?start=all

[Walter Moore]

I tried my idea, and it works but it seemed a little stiff, so I went ahead and bought a new breaker plate, magnet, and vacuum advance so that I could compare the two in operation. The hardest part to get was the vacuum advance unit. I tried two different part numbers before I gave up and ordered the last number listed in the ZX parts listing shown on Xeons130's page.

(22301-P7901 by the way...)

I have not put the distributor back together yet (More on that later) but I did compare the operation of the two plates, new and refurbished, mounted in the housing with my air-vac. The repaired plate moves in response to full vacuum, but it is noticeably more sluggish. The new plate snaps back and fourth instantly, while my hayseed repair takes about 1/2 second longer to move.

In the process of this testing I noticed that the new breaker plate, part number referenced in the earlier post by 280~Master, allows the vacuum mechanism to rotate the timing MUCH further than the original plate allows. Using a little thumbnail trigonometry I estimate that the original plate is moving about 8.5 degrees while the new plate is moving nearly 13. Since the FSM for the 79ZX shows my distributor moving 9 degrees (18 degrees at the crankshaft) I am guessing that the new plate isn't quite the part that I need.

I have spent most of the weekend playing with spread sheets, rivets, J-B weld, and Dremmel tool trying to make the two plates operate identically.

When I get the distributor back together, and have a chance to test it on the car, I will report on my results. (With pictures and charts, I promise.)

But the car is running so good right now that I really hate to mess with it. So it may be a while. Then again I love playing with things... :stupid: