280ZX Distributor Rebuild Questions About Vacum Advance Disabling And Ball Bearings

[Guest iskone]

Just picked up a 79' dizzy w/ an E12-80 mudule.

 

Of course my bearings are gone I've been reading and have gotten the idea that I leave them out when disabling the vacum advacne. Is this correct?

 

I've also read that I should "lock" the vacum advance unit in place. Why don't I just leave it out all together and seal up the hole left behind?

 

Isk

[JMortensen]

You can't leave the entire vacuum advance mechanism out completely because it holds the pedestal thingy that the stator attaches to. What I did was to JB weld the support pedestal thingy to the vacuum advance plate, then JB weld the advance plate to the breaker plate, leaving out all the balls and all that. Then I took the diaphragm and cut the arm off and stuck it back in just to fill the hole. You could probably plug that hole in the distributor instead if you didn't want the diaphragm there.

[JMortensen]

I forgot to mention that the main issue when you remove all the bearings and all that is that the pedestal stay square while your epoxy is drying. It can lean over, and if it does than the distributor shaft will rub on the pedestal. So one of the main goals is to keep everything square so that nothing rubs.

 

This all should make sense when you get it apart, if not just post again!

[Guest iskone]

What about the bearings that go under the triangle thinbg?

 

[Guest iskone]

I toook apart the breaker plate and reassembled it after cleaning, should I put any grease on it? Dielectric? I don't see any in the pics but it seems like I should.

 

Isk

[JMortensen]

I just took all that crap off and JB welded the plate to the center pedestal part. You're not running the vacuum advance, so why bother putting all that stuff back together just to epoxy it all together?

[Guest iskone]

Arghhh, Now I'm confused. What parts do you take out and do do you JB weld together?

 

Should I post some pics of everything disassembled?

 

Isk

[eec564]

I used a thin coating of lithium grease on mine, very slick and oil/water resistant. Dielectric shouldn't be necessary, there's no electricity anywhere in the system.

I suppose the easiest thing to do would be to use spacers (see my rampage further down) where the plastic race was, if you can't get a new one, and as long as they don't interfere with anything, then use the non-hooked-up vaccume advance arm to hold the breaker plate in place. There's no advantage to not having the vaccume diaphram/accuator in the distributor when it isn't hooked up, but as I said above, it can be used to keep the breaker plate from moving so you don't have to glue it, which gives you the major (IMO) advantage of being able to go back to using it some day, if you need to or wish.

 

Food for thought: What I ended up doing when I got my Z and there was nothing left of the plastic race, was replace the ball bearings in the plastic section with precisely measured extremely thing washers I made on a lathe. Then I coated everything that moves with white lithium and re-assembled. Everything works as it should, except you need to get EVERY burr out of the washers otherwise the vaccume advance (I'm still using mine) sticks, then jumps to whatever position it should be in. Even then, never caused pinging or noticeable loss of power.

 

-Eric

[eec564]

Also, you should deffinately go here:

http://www.atlanticz.ca/zclub/techtips/distributor/index.html'>http://www.atlanticz.ca/zclub/techtips/distributor/index.html

 

And here too, for the main techtips page:

http://www.atlanticz.ca/zclub/techtips/

 

-Eric

[Guest iskone]

I've been using the first link as a guide. I just gotta figure out what to JB weld and I think IU should be fine.

 

Oh know where to get a new magnet that goes under the stator? Mine is cracked in there pieces.

 

Isk

[eec564]

I belive nissan still sells the stator and the magnet under it as one piece, it's listed in their computer as an avalible part. Should be less then 20$ but will take a while to deliver. Making friends with someone who works behind the parts counter might also be a good thing.

Also, unless you want to lock the mechanical advance, simply not hooking up the vaccume line to the actuator/diaphram is the way to go IMHO for not using it. You don't have to heavily modify the distributor and you can go back if you have to. The return spring in the actuator is more then enough to hold the breaker plate in place.

 

What did you do about the plastic race that is always broken? Replace it with a new one? I could only find it sold as a unit with the entire breaker plate assembly, for way more then I wanted to pay. Asside from that, everything else in my distributor was fine, just needed a bit of steel wool and sand paper.

 

-Eric

[JMortensen]

I bought the stator from Courtesy Nissan about 2 years ago and it did NOT have the magnet on it.

 

Isk has a .500+/300+ cam on an engine with almost 12:1 compression. He isn't going back to vacuum advance.

 

The reason to permanently lock it down has to do with vibration. Vibration does weird things, like loosening bolts, and tearing apart harmonic balancers. Everything is vibrating like crazy at 7000 rpm. If you lock down the breaker plate then it CAN'T move, which is what you're looking for on an engine that could detonate itself to death quickly like his 11:1 + compression engine if the breaker plate vibrates and advances itself.

 

Isk, take a step back and think about what you're trying to do. You want to prevent the vacuum advance mechanism from ever having any effect on the timing whatsoever. You don't need the bearings. You don't need the little bearing retainers. Try to put it back together with the minimum number of parts that you can. So you basically want to lock the whole damn thing solidly together, and only have the breaker plate in there to locate the stator.

 

If you get really stuck I'll pull mine apart and take some pictures for you, but if you think more about what you're trying to do rather than what pieces you should use and what you shouldn't, I think you'll do fine.

[Guest iskone]

Well my magent is actually in 5 peices. The dealership can't get them so the guy at the parts store is gonna make sure he can before he orders it.

 

Think I got it now. I can just keep the circluar plate and the cupped shaped one, JB weld them together and be done with it. When I JB weld them together I'll do it so the cupped portipon is all the way RETARDED. Sound right?

 

278*/580 Never going back to vacum

 

Isk

[JMortensen]

You got it now. If you can figure out how to set it so that you don't have to change the dizzy drive a tooth that's even better.

[Guest iskone]

You're saying to set the motor to TDC then JB it all with the rotor at 1? Hmmm I could pull it off I supose. But now I have to wait anyway for the stator. I'll still get it JB'd but I'll probably just set it up at full retard so I can jump right into the fuel system. I mean my the setup I have now works so I don't want to spend much more time with this new setup just to wait.

 

Isk

[eec564]

The position of the breaker plate assembly shouldn't affect the position of the rotor at all. The breaker plate only moves the stator, the reluctor and rotor only change position relative to the bottom of the shaft due to the mechanical advance. The position you JB your breaker plate in will determine your base timing, before you adjust it by moving the distributor. As long as you know the correct position in the star (turbo dist/oil pump) when re-installing the distributor you'll be fine, with a non-turbo

it's nice and one-way keyed, so you can't miss it.

I wouldn't like to try JBing it while it's still on the motor, especially if it's in the car.

 

-Eric

[Guest iskone]

Well, Westbay never came through and when the "stator" finally came in it was the pick up coil. I can get a new magnet from Z secialties for $20 but it'll be a while.

 

Isk

[Workinprogress]

Interested in pics when you get it figured out

[ezzzzzzz]

I'm rebuilding a 280zx dizzy for my triple carbed L24. Actually, the distributor is in excellent condition overall. There are no broken or heavily worn parts. I intend to disable the vacuum advance by drilling a small hole through the two plates, tapping and installing a small machine screw to keep them fixed to each other. I am thinking I could extend the hole already there for the dashpot arm but I don't have the part in front of me to confirm that. The reasoning is I can easily go back to a vac advance if needed for another application. A simple aluminum plug will be machined to fill the hole where the dashpot would reside. It will make things a little cleaner visually.

[Guest iskone]

That's not a bad idea as long as the screw never backs out.

 

I just got the magnet ordered so hopefully I'll have it Monday.

 

Isk