72 240z distributor question

[my240]

Since I've owned this car (almost 50 years) the timing on the distributor has been very close but needs just a tad more. There isn't any more adjustment to turn it. Should I pull it out and set it back one tooth? Runs fine, but could be better.

Thanks

[Zed Head]

There are other ways to get a "tad" more.  You could file the slot open a tad more.  Nobody can really answer a should question.  Should is in the brain of the doer.  

[Patcon]

Do you realize there are two slots? There is one with the bolt on top and one with a bolt on the bottom...

Had to pick up "Captain Obvious's" slack...

[Zed Head]

Patcon makes an excellent point.  There is definitely a few degrees of extra on the other adjustment.  I dinked around with mine when I was trying to clock my rotor for better centering over the electrodes, when I was trying to run more advance.  Funny though, eventually I got tired of trying to squeeze out a few more HP fractions and set everything pretty much back to stock.

The FSM shows it with the bolt still in it.  You can't see it from the top.  I marked the slot that you can see also.

[Captain Obvious]

Thanks for the cover. You're the best!!  

[my240]

You guys have jogged my memory a bit. 40 years or so ago I was told to try this new distributor for better performance. I took mine off, and decided to keep what I had and put it back on. I had to be a tooth off. I told myself I will go back and reset but never did. I could turn everything to get close and just pretty much forgot I did it. And yes I'm fully aware there are two bolts. I have a few antique cars that I've built and try to stay mechanically sound.  This problem was caused by me years ago which I will fix over the next few days. 99% of the time it's the mechanic not the cars fault. I just put new radiator hoses on and wondered what you guys thought about aluminum radiators? I still have the original. 

One last thing. I have the original keys but need another set made. Where do you buy a good set of blanks. Rt and Lft.

Thanks

Edited February 27, 2018 by my240
forgot

[Zed Head]

It can't be a "tooth off" unless you removed the oil pump.  Or you have a US V8 engine installed.  The Datsun distributors use a slot and a tang to tie the distributor shaft to the drive shaft.  It can only install one way.

Just curious, but what timing are you running now?  What's the light say?

[my240]

It must be about 8 deg. If removing the distributor didn't do it,,how did I lose all the adjustment. Both the adjustments are cranked to the right as far as they'll go. If you move back car will rough then quit. Points are at 35 dwell.

[Zed Head]

I've read about the drive gear slipping on the shaft.  It's not common though.  

Doesn't look like you're actually measuring and there are other things that could be wrong.  Seems like verifying where things are at would be easier than dropping the oil pump and moving the drive gear over a tooth.  That's what you'll have to do to get more adjustment.  I was just describing how the distributor drive works, above.  It's not like a Chevy or Mopar where you just lift the distributor up and re- "stab" it a tooth over.  It only fits one way, in one position.

Good luck.

[SteveJ]

On 2/27/2018 at 1:26 PM, Zed Head said:

It can't be a "tooth off" unless you removed the oil pump.  Or you have a US V8 engine installed.  The Datsun distributors use a slot and a tang to tie the distributor shaft to the drive shaft.  It can only install one way.

Just curious, but what timing are you running now?  What's the light say?

We like to say that the distributor can only be installed one way, but I have seen on more than one occasion where someone managed to install the distributor 180 degrees out. Don't ask me how it was done. I only know that some people can do it.

[SteveJ]

On 2/27/2018 at 3:47 PM, my240 said:

It must be about 8 deg. If removing the distributor didn't do it,,how did I lose all the adjustment. Both the adjustments are cranked to the right as far as they'll go. If you move back car will rough then quit. Points are at 35 dwell.

Can you get a clear photo of where your timing mark is and post it? You should easily be able to get more than 8 degrees timed in. As a matter of fact, post several photos of the engine bay with many around the distributor. Bandwidth is cheap.

Otherwise, make plans to come out to the Mitty at Road Atlanta in April. I'm sure I could find more than one person I would trust who could tell you what's going on with your car.

[my240]

I'll try to get back over to it to get some pics. I widened the point gap and it seemed to give me a bit more response at carbs and timing at 10. Understand this car doesn't run more than a few hours a year. So I'm aware of the fact that other things could be acting up. I went thru the carbs last year so I feel confident there pretty close. Raining every day so moisture could be playing a part. Overall I'm happy with the way it's running, just not clear why adjustment on distributor is limited. Also, where is good place to get key blanks. Need to get a set.

Thanks