Firepower

[52crankman]

Anyone know how to get a hold of the member; Firepower.  I am interested in his experience with 123 Ignition for my 240Z.

[siteunseen]

@Firepower

Is one way. He'll get an email hopefully.

Good luck.

[Mike W]

I can probably help you with the 123 ignition.  I believe that I was one of the first to actually install and use this in a Z and did a pretty extensive write up after I completed the install.  You can find my thread here:

All in all I am very happy with the system although there are a few quirks you should know about before you start.  A quick summary for you:

1. On install the instructions will tell you to get the engine to TDC, install the 123 and apply power, and then turn it in the direction of rotation until a little green LED lights up.  In theory that should put the 123 also at TDC with 0 degrees advance.  Well that was not the case with mine.  After I completed the install I programmed the 123 with a 0 degree advance curve and checked my timing at idle.  It should have been at TDC but in fact I was about 12 degrees advanced.  So I ended up loosening the dizzy like you would the oem one, and just turned it until I was at TDC at idle.

2. If you are running an MSD with the 123, you will likely experience random rotor failure over time.  It turns out that the 123 rotor has an internal resistor embedded between the top contact and the end contact and it was not designed for use with an MSD type of ignition and will eventually burn out the resistor making the rotor useless.  You can either carry spares (which is what I did until recently when I discovered the root cause of this issue)or you can Dremel out an old rotor and replace the resistor with a 12 GA wire.  Interesting that 123 actually sells these modified rotors on their website so clearly then know about this weakness.

Those are the 2 main issues that I recall.  Other than that it is a breeze to program (I have the USB version) and performs well.

Feel free to PM me if you have other questions or just respond to this thread.

Hope that helps.

Mike.

 

[AK260]

Mike pretty much said it!

Oh and don’t trust the no.1 HT lead mark on the dizzy cap - I blew up my silencer and scared the neighbours as a result ;)

ALWAYS check timing with a timing light at idle and all in. Leave nothing to chance when it comes to timing.

And here is another write up I did a while back, hope it helps:

https://zclub.net/community/index.php?threads/123-ignition-for-datsun-l6-on-my-l28.25467/

[52crankman]

Here is the information I was requesting from Firepower:

I have a 1972 240Z and recently completed a 2.5 yr restoration.  I have purchased a 123 ignition but have been waiting to install it until after getting the car back together and running.  Am now ready for the install.  I purchased a non-blue tooth model.  Would you mind providing the following:

1) some pictures of your install.  Interested in keeping wiring as stock as possible and use original tach.

2) do you any install instructions or recommendations

3) do you mind sharing the timing advance and vac advance curves that you used (my car is basically stock with a mild cam)

 

 

[Captain Obvious]

I got nothing technical to add to this thread.

My only question is does it really belong in the "club website" sub-forum?  @Mike

[AK260]

Bluetooth or not, your tac signal runs off the coil wiring - that shouldn’t change with 123.

 

Edit: I think the 240 wiring is different to my ‘77 260 so you may need a resistor somewhere in the circuit. I will let our wisened elders comment.

 

As for timing curves, the FSM is your best bet.

 

With timing you have 3 advance points to consider:

 

Static timing (or base timing): this is how far advanced the distributor is when installed and without the engine running.

 

Centrifugal advance: increases and decreases with revs.

 

Vac advance: engine load dependent - I.e. wide open throttle is zero vac and zero advance, foot off the throttle is max vac advance. This is used to improve emissions/ fuel economy, keep your engine cooler at idle and improve throttle response from off to on power.

 

Now, “all in” refers to Base + Centrifugal timing (but no vac).

 

So, typically, the best way we set up old distributors is to disconnect vac advance and put a bung over the front carb’s vac pipe. Then turn the fast idle screw up so you have say 2800 rpm, then set the “all in” timing at anywhere from 30-34 degrees. I find that with a stock dizzy at 34 @3000rpm my idle timing sits around 17 degrees. Then when you connect up Vac you will see another 15 degrees added. This is perfectly safe as the mix is very lean at idle / part throttle and needs the additional timing to burn fully.

 

Now onto the 123. Pay great attention to this. Take your plugs out, turn the engine by hand (using either the cam sprocket bolt or the crank pulley - I cant get to the latter on mine). Put the engine at the static / base timing point. I use zero as what I see on the 123 curve is what I get when the engine is running but it does require extra cranking for cold start. If you don’t go for zero do yourself a favour and set it at 10 degrees as it’s easy to subtract later.

 

Now, if you are aiming for a stock curve, then I would go with:

 

500 rpm (anti-stall): 7 (optional)

 

800 rpm (idle): 5

 

2400 rpm: 18

 

3500 rpm: 20 (optional but works well)

 

6000 rpm: 24 (optional for best top end power)

 

Remember the above numbers are 10degrees less to account for the static / base timing.

 

Connect the vac but leave it at 0 degrees for now and run with this set up to see if you are happy with the way the car runs.

 

When you are happy with this, monitor the MAP gauge on the app or use a normal vac gauge and determine how much vac you are generating at idle and at 3000 rpm. Then set 10 degrees (your stock dizzy does 15 but I like to play safe on vac for various reasons one of which is the unknown “rate of attack” with the 123).

 

Here is FSM vac curve

 

 

 

Here is a great table - see if you can find your stock dizzy

 

 

Apologies about the rant but it was a long commute to work ;)