260z or 280z Distributor into 240z

[Harry Dinkle]

Hey Folks,

I have read extensively about putting a 280zx distributor into 240z and that seems like a great upgrade.  However, 260z and 280z both had electronic ignition distributors and I was wondering why people don't swap those into the 240z instead/also.  The reason I am asking is because I can easily get rebuilt 260z and 280z distributors and they bolt right in with no differences to the dizzy mount as far as I can tell.  However the 280zx distributor has a different mounting block and I can't seem to find any of those to purchase, I don't think they are included in the rebuilt Cardone distributors.

I feel like this answer should be out there, but I have been searching this forum and others for literally hours and have come up short.  Tons of 280zx info and nothing about 260 and 280.  

Appreciate the help.

[SteveJ]

I haven't tried the conversion to a 260Z or 280Z distributor. I went with the ZX conversion in my 73. A PO did the conversion in my 74.

The 260Z and 280Z used a transistor ignition unit (TIU) to control the spark. You would to need to figure out how to install a TIU into the car. Another alternative would be to use a GM HEI to trigger the spark. There is information online (including this forum) from people who have converted their cars to use an HEI module. 

I cannot say what would happen to your tachometer with either conversion. It may require figuring out how to adapt a 260Z or 280Z tach into your wiring.

 

[EuroDat]

The reason why the early 280ZX distributor is a popular upgrade is simplicity. It is a complete unit with the "matchbox" TIU built into the side. Less wiring.

The 260Z and 280Z units use a bulky external TIU outside the distributor and preferably wired in the cabin out of the weather. Using a 4-pin HEI module would reduce the bulkiness, but it's still external. The 280zx dissy has a better more powerfull VR pick-up and runs a 12v coil, no resistor block. The 260Z and 280Z up to August 77 used a 7v coil and resistor.

[Harry Dinkle]

I really appreciate the responses. I was thinking the 260z with Pertronix d2000 hei module would be pretty straight forward, reliable, and allow me to keep my ballast/coil setup and functioning tach.  I may upgrade the coil to 3ohm, get rid of the ballast, and figure out the tach wiring. 

[Zed Head]

There are many ways to get electronic ignition in to a 240Z.  Somebody just posted about the Pertronix Ignitor II, which has current-limiting technology.  That, apparently, will swap right in where the points were.  The GM HEI module and the ZX module have current-limiting technology also.  They all will work without the ballast resistor.  The ballast limits current and gives a weaker spark.

EuroDat wrote up a procedure with the wiring diagram for using a GM module with a 280Z distributor.  As he said, it really comes down to simplicity.  

 

[Zed Head]

Here's that writeup with the wiring scheme.

 

[Zed Head]

And here's the recent Ignitor II thread.  It's not been clear that the Ignitor II would work in a 240Z, they didn't show it as an application.  but apparently it does.  There's also the 123igniton programmable distributor.  Which brings up the issue of timing advance curves.  If you get a new distributor you'll probably get a different set of curves.

 

[siteunseen]

'79 ZX dizzy works great. If you can't find one at a junkyard zcarsource.com has the base mount you'll need. I bought my cardone from Amazon. Com then you'll need the bigger cap and rotor button. Also you run the ZX spark plugs wider gap.

I bought the flame thrower after reading some bad reviews on the yellow coil, can't remember the name of it now though.

[Harry Dinkle]

Thanks again, remarkably helpful group. I guess i should have prefaced this by the fact that my 240z distributor has an pertronix ignitor in it but the dizzy appears to have slop in the bearings so i want to get a new distributor. This could be a complete misdiagnosis, but hey, that’s my decision.

My first choice is a remanned 240z dizzy but i can’t find one with single points for a reasonable price. My second choice is the 280zx system but i can’t find the mount as i dont think it is included in the reman kits. Zcarsource appears to not have any in stock. so that leads me to the 260z reman dizzy with HEI module. 

Edited July 30, 2018 by Harry Dinkle

[EuroDat]

1 hour ago, Harry Dinkle said:

I really appreciate the responses. I was thinking the 260z with Pertronix d2000 hei module would be pretty straight forward, reliable, and allow me to keep my ballast/coil setup and functioning tach.  I may upgrade the coil to 3ohm, get rid of the ballast, and figure out the tach wiring. 

Like Zed head said. If you go with the 260Z dissy and a HEI module, you should use a coil with less than 1 ohm. Then you can take advantage of the current limiting capabilities of the HEI module.

You can make a bracket and mount it next to the (12v) coil where the ballast was mounted. Make sure the bracket has good contact with the HEI to help remove the heat.

Edited July 30, 2018 by EuroDat
Mmm dutch spell checker kicking in.

[Harry Dinkle]

I just want to make sure I am clear on this since there are two wiring diagrams in the instructions (nice work on those BTW) but they don't indicate coil specs with and without the ballast and there are conflicting answers online.  

When you suggest a <1 ohm coil, do you suggest that with a 280z ballast such that the overall resistance is roughly 1.5-1.8ohm?  Or just the <1 ohm coil?  

I believe you don't need any ballast with the HEI module because as you have stated, it limits the current so there is no need for a current limiting resistor.  The Pertronix D2000 Flamethrower module limits current to 6.9A.  The 280z stock setup should be 6.6A (12v/1.8ohm) so it isn't a huge upgrade which is why keeping the stock ballast/coil setup in a 280z could be just fine.

My current planned setup is 260z distributor, Pertronix D2000 HEI module, Flamethrower II coil 0.6ohm, no ballast resistor.  Jump the two wires currently on the ballast so my tach still works.

[siteunseen]

If I remember right the '79 280ZX coil is a 1.5. Maybe google before you buy but I think it is lower than the 3.0 280Zs have.

Yeah chunk that porcelain ballast resistor. I went by Phillips instructions on atlanticzcars.com tech tips. Easy peasy. Runs great, tach works too. It's a head scratcher but it will all make sense when you get started. That dizzy mount will be your only challenge. It must be from the ZX.  If you find one at a junkyard be sure and get the wires and plug to the e12-80.

Good luck!