521 Distributor - Replace or Rebuild

[B_riginal]

hey guys, i am have issues with my 521 distributor and wanted to hear from you on weather you would purchase or rebuild the distributor.

 

Are the Thailand distributors any good?   

[banzai510(hainz)]

whats the issue? maybe its you?

yu should be able to get one free from someone.

[datzenmike]

Like what wrong?

 

An L16 distributor from the dealer for a 620 L16 truck is $250. (this may be in Canadian dollars) Taiwan? I would say you get what you pay for. 

 

Any L series 4 cylinder distributor will fit and work. They come in dual and single point but will work just fine and all have different mechanical and vacuum advance tweakss but that's tailored for mostly emissions. They will all work.

 

 

I think a Z series distributor ('81-'85 720 truck) should work on an L series engine. It's an electronic ignition (EI similar to the matchbox) it fires 8 plugs but if you don't care what it looks like just pull every other plug wire off. You can run with your coil and ballast or get the matching high voltage output coil and get rid of the ballast.

[B_riginal]

thanks datzenmike, one of the distributor wires is frayed pretty good. but the spark is very week at the points. 

 

first I noticed the truck running at a high idle, then the next time I wanted to drive it, the truck just died while warming up. 

[B_riginal]

11 minutes ago, banzai510(hainz) said:

whats the issue? maybe its you?

yu should be able to get one free from someone.

ouch, maybe it is me. 

 

why would i be able to get one free?

[B_riginal]

14 minutes ago, datzenmike said:

Like what wrong?

 

An L16 distributor from the dealer for a 620 L16 truck is $250. (this may be in Canadian dollars) Taiwan? I would say you get what you pay for. 

 

Any L series 4 cylinder distributor will fit and work. They come in dual and single point but will work just fine and all have different mechanical and vacuum advance tweakss but that's tailored for mostly emissions. They will all work.

 

 

I think a Z series distributor ('81-'85 720 truck) should work on an L series engine. It's an electronic ignition (EI similar to the matchbox) it fires 8 plugs but if you don't care what it looks like just pull every other plug wire off. You can run with your coil and ballast or get the matching high voltage output coil and get rid of the ballast.

 

5 minutes ago, B_riginal said:

thanks datzenmike, one of the distributor wires is frayed pretty good. but the spark is very week at the points. 

 

first I noticed the truck running at a high idle, then the next time I wanted to drive it, the truck just died while warming up. 

 

[datzenmike]

High tension wires? Replace if a visual inspection shows wear or damage. Any other wiring just replace. Engine stalling can be a hundred things other than the distributor. 

 

Replace the points and the condenser if you haven't already and check the gap is  about 0.020". Don't forget a very small dab of grease on the rubbing block. The condenser can short internally and foul up the spark.

 

Check the distributor cap and rotor for cracks or damage and replace as needed.

[Crashtd420]

Is it a single points distributor or dual?

If it's just an electrical issue and you have single points you could simply do the pertronix upgrade....

But I also think you can get an electric version from oriellys for about the same money.... you'll just need to look at the 620 for when they switched from points.....

 

I think what Mike and hainz were getting at is oem will always be better... most datsun owners do tend to have a surplus of parts....

Also most try to upgrade to the matchbox distributor so they probably have their old points distributor collecting dust.....

Edited July 19, 2021 by Crashtd420

[banzai510(hainz)]

33 minutes ago, B_riginal said:

why would i be able to get one free?

Alot of Datsun got converted over time to upgraded distributors or just threw them away when the KA/ SR motor swaps cam in. so many people with have a collection of distributors

I think I have 3 dual point dist. Its the single point that people want for the Pertronix conversion ability.

 

long as the bushing isnt worn out , If I remeber right i think you said yours is locked up on the vac adv. Like I said just put the motor to 12-14 BTDC.  I wouldnt even use the 2nd set of points

 

Some body near you has a dist near you. I just am not going to go to the postoffice. if local I would give it too you.

[B_riginal]

35 minutes ago, Crashtd420 said:

Is it a single points distributor or dual?

as simple of a question this is, I do not know the answer. 

 

It appears to be stock or replaced a long time ago. 

[banzai510(hainz)]

7 minutes ago, B_riginal said:

as simple of a question this is, I do not know the answer.

????????????????????????????  single or dual?  I will assume dual/

then gap them correctly and time the motor and retry how it runs. A weak spark might mean you need it gapped correctly.  Changing stuff to change it will not fix this untiell you gap the point to even see if out of adjustment.

 

sound like a simple fix to me

Edited July 19, 2021 by banzai510(hainz)

[mklotz70]

There's some pics of a single in this thread....

 

If you take the cap off of yours and you have two sets of points, than it's a dual.  If someone removed the second set, you'll still see the area where the second set would go.  If you have the two, you can either set the second set with a gap so far that that they ever touch, or remove them.  You can also find pics in the factory service manual which can be downloaded in several places.  

 

Most people get excited when they hear dual points, but these are not like the ones in american cars.  The american cars had them so that they could handle twice the current.  The ones in the 521's are purely for emissions.  There was a switch in the trans and another on the throttle linkage.  When decelerating in 3rd gear, the 2nd set would kick in and retard the timing.......basically useless these days.  The 2nd set is not exactly 180 degrees from the primary set, so you do NOT want them in the circuit at any time....unless you really want that emissions feature.  Best to just remove the 2nd set.  

 

Your best option is to convert to the matchbox dizzy and run a dedicated ground from the body of the dizzy to the chassis.  The additional ground makes them bulletproof. 

 

Another option is to use an HEI module with your points.  There's some info on this page.....you can google to find more...

 

 

A strong spark at the points is not your goal. No spark would be the best.  The coil field collapses through the spark plug when the points open.....the longer it sparks or the stronger it sparks, the less the field goes through the plugs.  Points closed charges the coil. When they open, the field collapses.  The condenser is there to help make that happen and if it's bad, the process doesn't work well at all.  You can google how a points ignition works for a better understanding.   

[Stoffregen Motorsports]

20 hours ago, banzai510(hainz) said:

 

I think I have 3 dual point dist. Its the single point that people want for the Pertronix conversion ability.

 

Dual point distributors can be made to work with the Pertronix.

[banzai510(hainz)]

We have to have "B riginal" open up the cap first before we get to how to convert a dual point to a single reline up the holes for the Pertronix to mount down

[B_riginal]

<a href="https://imgur.com/XiNmOXU"><img src="https://i.imgur.com/XiNmOXU.jpg" title="source: imgur.com" /></a>

<a href="https://imgur.com/yeayZxw"><img src="https://i.imgur.com/yeayZxw.jpg" title="source: imgur.com" /></a>

[datzenmike]

Always check what you posted is correct and working. If possible learn how to post the actual picture, I hate clicking on links. Ingur has lots of posting options, try them all and find something that works. I can't do anything with that

[B_riginal]

1 minute ago, datzenmike said:

Always check what you posted is correct and working. If possible learn ho to post the picture, I hate clicking on links. Ingur has lots of posting options, try them all and find something that works. I can't do anything with that

yeah I agree, i hate link too. I was hoping they would convert to an image after submitting. I will figure Imgur out, thanks. 

[datzenmike]

Hell I just try everything till I get something that works. Select your picture and over on the right find Direct Link. Hit the COPY just to the right of it and come back to Ratsun select where you want to put your picture and hit CTRL and V. There may be several ways, this works for me.

[B_riginal]

I guess ratsun. net doesnt need photo sharing site anymore. attached is my distributor for my 1970 521. 

Edited July 27, 2021 by B_riginal

[datzenmike]

Dual points. Back in the day dual points were a way to increase the dwell time. First set closed. Then the second set, first set opens but second are still closed. Second set opens and coil sparks. It would carry more current but I don't think that was the intended use. The last set to open would arc weld the points in short order.

 

On a Datsun the last set open about 4 degrees after the first set. An easy way to add or remove 4 degrees of retard for emissions. You can wire them together and set the timing on the second set opening time.

[B_riginal]

 

1 hour ago, datzenmike said:

On a Datsun the last set open about 4 degrees after the first set. An easy way to add or remove 4 degrees of retard for emissions. You can wire them together and set the timing on the second set opening time.

I wish I knew what you were talking about. This is over my head and I will need to consult with a mechanic friend with what you are saying. Thank you for your time.

 

Is this a situation that could benefit from replacing the entire unit?

[datzenmike]

NO!!!! Do NOT throw parts at this. What will happen is a sub standard piece of shit made in China/Taiwan will introduce 4 other problems. Keep the original distributor it's good quality. Only thing that wears out are the points and maybe the condenser. This is normal.

 

 

 

 

Those points look OK.

 

Pull the Blue/Yellow stripe wire off and electric tape it. This will get rid of the retarded set and it will run full proper advance on the primary points.

 

 

 

The primary points (Black wire) set on the high point of the cam so they are fully open and adjust or check that it's opening to 0.020".  

 

Pull the high voltage wire of the center of the distributor cap and hold about 1/4" away from the intake manifold or anything grounded and turn the engine over with the starter. Got nice fat spark??? I bet you do. Your running problem isn't electrical, probably carburetor.

[B_riginal]

Datzenmike, I am going to try those steps on the distributor this weekend. I think you maybe right. My carburetor is likely the issue. It was idling high just before it stopped running. 

 

I am wanting to keep this truck running reliably for many years, so good reliable parts are better then cheap fixes. Thank you for your help. 

[banzai510(hainz)]

well get the distributor figured out as to me there is most issues from a distributor that a carb I seen over the years esp a oil point DUAL point.

point wear condersor bad

worn dist shaft bushing

spring weight fall off or break

vacuum advance

 

Faster you get a Pertronix conversion or a EI the better as once its good then one can figure the carb is more likely a suspect

[Stoffregen Motorsports]

There are other wear parts in the distributor. The main bushing, both the ID and the length. Mopar distributor shims can be used to shim the end play in the shaft, and this helps keep the timing more accurate. Also, the slots in the distributor cam can wear, but it's not common.