Hitachi 280ZX Distributors

[240260280]

Good news. Just got ZX distributor to work with 240z tach. Ballast was needed.

[Av8ferg]

Good news. Just got ZX distributor to work with 240z tach. Ballast was needed.

I thought you had to removed the ballast to get the ZX distributor to work properly.


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[SteveJ]

47 minutes ago, Av8ferg said:

I thought you had to removed the ballast to get the ZX distributor to work properly.


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I had the 280ZX distributor working on a 260Z and a 240Z with the ballast resistor. On the 260Z I later bypassed the ballast resistor.

[240260280]

59 minutes ago, Av8ferg said:

I thought you had to removed the ballast to get the ZX distributor to work properly.


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Removing ballast gives higher energy spark.  It is really only needed for high engine-compression applications. A 280z tach works fine with this upgrade.

Keeping the ballast allows older 240z tach to work which saves having to swap it AND allows the 240z owner to get rid of the points distributor. They just forego the high energy spark.

 

[madkaw]

I’d remove it - one less thing to go bad . Cleans up the wiring . Just me 

[AK260]

AK260, that’s one impressive write up. So if your 280zx distributor was working flawlessly what did you order another one. Did the worm shaft cause problems?
It’s a lot of coin for that 123 distributor. Would you say it was worth the $$. I’m sure it’s more reliable.
I started tearing one of mine apart because it’s dirty and rusty inside. No sure how it’s gonna pan out. My first time doing this.
I get the reliability thing on old cars. The more complicated the mechanics the more can go wrong. Heck I was victim to your homelands diabolical creation the....flew the AV8B Harrier i (a mechanical and maintenance nightmare). Somehow I lived through it.
Old cars can be made reliable enough, and having working spares on hand in the trunk is smart. This is what I have 3 EFIs.


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Good questions! My 280zx dizzy was flawless - the main reasons for changing were 1. my tuner told me the shaft wobble (albeit small) would reduce timing accuracy further up the revs, 2. I wanted to customise timing to match my modified engine’s characteristics (I was paranoid about knock and pinking) 3. Having a very rev happy engine, I wanted to add a rev limiter to protect against a potential sticky throttle / linkage blowing the engine up mid gear change. Oh and I love the immobiliser function that works from my phone.

I liked the relatively plug and play nature versus crank triggered etc options and the “classic” look of a distributor.

I probably would buy it again even with it’s rough edges but the other options mentioned above are definitely worth considering.

AK260 could you please post your MAP curve that you are using. Thanks
 

I’ve been very occupied with playing with the mix and custom timing at specific revs to reduce the two giant torque holes I get at around 2.2k and 3.5k rpms. So I haven’t had a chance to get the vacuum gauge out to properly set up the vac advance. I don’t fully trust the dials on the app as their rates of responsiveness isn’t consistent - I suspect the Bluetooth connection has a lot to do with it.

For that reason I don’t have a map curve I’m happy sharing but at the moment I’m playing safe and only really adding proper advance at motorway / cruising vac. This is nowhere near optimised yet ....



Oh and for giggles, here’s the curve my engine is happiest with, she really doesn’t like too much timing too early ...



This makes the torque holes feel more like flat spots.

I fear I may have taken the thread slightly off topic ;)

[siteunseen]

1 hour ago, madkaw said:

I’d remove it - one less thing to go bad . Cleans up the wiring . Just me 

I'm with Steve. If you won't have to get inspections get rid of it. Less cracks to break in the futute.

[Zed Head]

10 hours ago, 240260280 said:

Good news. Just got ZX distributor to work with 240z tach. Ballast was needed.

That's odd.  What does it mean?  With ballast the coil would take longer to "charge" and current flow (voltage) would be lower, but last longer.  I wonder how you could modify the tach to offset that.  More loops on the back of the tach to make it more responsive to the shorter time?

Interesting finding.

[240260280]

56 minutes ago, Zed Head said:

That's odd.  What does it mean?  With ballast the coil would take longer to "charge" and current flow (voltage) would be lower, but last longer.  I wonder how you could modify the tach to offset that.  More loops on the back of the tach to make it more responsive to the shorter time?

Interesting finding.

I think you may be on to something. I can think of two possible causes:

1. Resistance in circuit changes current pulse shape (RC rise/fall time increases)

2. Higher current without the resistor saturates the detector circuit and it does not work.

 

I tried more loops in the past with no luck.

Edited March 3, 2020 by 240260280

[Av8ferg]

So, I’m tired of researching this distributor issue. There are obviously many solutions to this, if my I have my facts right.
BTW, both of the old 280zx distributors are probably not salvageable. I’ve stripped them down and both have broke parts, and significance rust. I’m not confident the work will be worth the effort. Here are my options as I see it. My expectations are alway best performance and reliability for the $$. I don’t want to ever have go back and buy again because I chose poorly the first time. Buy it once...do it once.

1. Buy and rebuilt ZX Cardone Distributor. Not sure if they are worth a crap. Many don’t come with the module.
2. Buy a rebuilt 280z Distributor, maybe put the Pertronix pickup in it and use one of my ZX e12-92 modules.
- option 1 : try the GM HEI mod (I read they aren’t very reliable and might have an RPM limit) cheap and easy.
- option 2 : use Pertronix hi perf HEI $50
- option 3 : buy an MSD and set it and forget it.
3. 123ignition ( will have to hide the check book from my wife option)

You smart guys that have been discussing this stuff at the PHD level for the past few years before I ever owned a Z...I’d like you opinion.




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[Zed Head]

You can run an MSD or Crane or other using the 280Z distributor as a trigger.  You still want the advance mechanisms to work right.

The GM HEI rev limit is an old and unfounded rumor stated by David Vizard many years ago, in Chevy world.  GM has used the module in their cars for many many years.  I dug in to it once, a while back.  See below.  Again though, the advance mechanisms need to be right.

Pertronix has shifted to offshore manufacturing.  There are questions about the quality of what you would buy today, versus the guys who have had one for ten years.  And, advance mechanisms.

It's a problem.  Separate the advance control, vacuum and centrifugal, from the ignition module, in your thinking.  If you get a good distributor, like a 280Z unit, with a good breaker plate, you can use it to do a lot of different things.

 

 

[Zed Head]

None of that makes things more clear, does it?