I would like to improve my 1972 240Z ignition for a reasonable amount of money. Currently, I have the stock single point distributor and coil set-up. Does anyone have any suggestions? Also, how much of a HP increase could one expect?

I would be surprised if you get a horsepower increase by changing the ignition system. What you can get is a better running engine and, with a coil upgrade, a stronger spark. IMHO the best thing you can do with a points-type ignition is throw it away after replacing it with an electronic ignition. Lots of choices out there - I have a Mallory electronic distributor and a Pro-Master coil on my '71 240.

If you upgrade the ignition from points to electronic should you replace the coil as well? Is the stock coil from a 240 points type ignition not for 12v?

Stock coil would work, but if you are going to the trouble to go electronic, you may as well upgrade the coil for more voltage. Hotter spark, with better control of the spark equals improved performance. Or it should anyways. :cross-eye

I changed out my old '73 ignition and went with a complete '79 zx ignition . I picked mine up at the bone yard and bought the whole setup for '75.00. Even the pluggwires , cap , coil, and rotor were all in vary good shape in fact I have been running it all for over a year . If you do this be sure to get the coil bracket and the " stem" that the dist. bolts onto, you will need both . The coil is larger in diameter. Yes you will be able to feel the difference in performance and the idle will be much smoother.How much H P will you gain I havent a clue but one thing I get 23 MPG on the hwy and sround 19 -20 on the streets and freeway combo. And you will be able to run the stock tach. You will eliminate the ballest resister because it has the engine running on 8 v insted of 12. The electronic ignition runs on 12 all the time also you can open the spark plugg gap to 40k or so I am running at 44. I am using sylicone filled 8mm plugg wires, they were on the '79 when I pulled the dist.

I'm sure the stock ignition is no problem if you run a stock engine. But what if you upgrade the engine. I mean a F54 with flat top pistons N42 head. 10:1 compression. Would stock still cut it?

The limiting factor with an ignition is how it will handel the load at high R P M and not brake down. The stock ignition '79-'80ZX will handel to red line no problem. Now having said that if you go with an ignition like Jacobs , I have one of these on my v-8 , you will again see an improvement even farther .They are a little pricy mine was $ 400.00 + . There is a limit to what I expect from the little 6 , and we all need to be relistic in this area. If you want to just spend lots of cash and dump it into this fine little engine , by all means do it and the engine is able to task. However you will have an engine that will be srtaining to give you H P , now if you are just after power and dont have the 5 to 6 + thousand dollars to put into the 6 with twin turbos , and remember I said plus. Drop in a V-8 with a cam and duel quads a little head work and you will have more power than you can handel. Chev. small block engines can deliver one horsepower per cu, inch and more. Again to answer the ignition ? the '79 '80 zx ignition is all you need unless you are going to compete on the track or for bragging rights. One thing when I say Ignition that means the whole systime not just the dist. thats the best wires and the Coil all of it, Jacobs supplies a computer and igniter and other components that add to the later systime . Points cannot handel the load and will burn that is why they run on 8 volts. the early ignition starts on 12 and runs on 8 . Best of luck to you

Use the electronic igniton out of a 280ZX. It comes standard with the Hitachi set up. Use a 12V coil with this distributor

Check out:

http://www.gfs1.com/racing/articles/ignition.html

http://www.geocities.com/zgarage2001/engine.html

If I understand this correctly, I can take a 280ZX electronic distrubutor, transistor box, etc. and it is compatible with a 1972 240z in terms of distributor shaft length and distrubutor gear?

Yes.