zx distributor.Got serial no. info?

[nospark]

I've got an electronic dizzy, serial number D6K81-05 fitted to my 240z.
I've hunted the web to get specification info for this dizzy but no luck. The nearest I've come across is D6K81-01. All the D6K ones seem to have 17degrees mechanical advance and recommended 10degrees static advance - except those referenced as D6K80,D6K81, and D6K82 that recommend static advance as 8 degrees. These latter 3 come with a vacuum advance of 30 degrees, which is much higher than you'd find in more normal electronic dizzys,

So anyone got hard data/specification for a D6K81-05 ?

Anyone know if there was logic to Nissan's dizzy referencing system ? (D=dizzy; 6=6cylinder; K=electronic(?); numbers= ?)

Ta

 

[AliK]

Try this buddy ....

Original file is here ...

http://www.classiczcars.com/index.php?app=core&module=attach&section=attach&attach_id=33179

Discussion here ..

http://www.classiczcars.com/topic/31615-280zx-distributor-advance-curve-reference/

 

[nospark]

Thanks Ali,
I've got that data sheet as well as another one I found on the Aussi (ignition) forum. It points to my dissy possibly being in that red zone ie a vacuum advance of 30 degrees. I think the vacuum rating is stamped on the vacuum arm. Anyway, plan to strip my dissy as well as establish exactly what mechanical and vacuum I'm getting. (Carbs off and stripped at the mo). I just wonder why and on what cars Nissan thought it necessary to use a double rated vacuum canister.

 

[AliK]

Sounds like an Albrecht-esque question!

Be good to hear how you get on with it!

 

[jonbills]

I'm guessing, but I expect the red zone isn't a problem for the original applications because there's an ECU to retard ignition at the times when that much vacuum advance is unwelcome.

 

[AliK]

So the dizzy is more intelligent than appears then?

 

[jonbills]

I don't know for sure, but I did read that the later 280zx dizzy's have ECU control which is why when transplanted to earlier cars you need to apply 12v to the extra terminal to stop it over advancing.

in any working L engine ignition, SOMETHING must be acting to prevent total advance exceeding 35 degrees when the engine is under load.

 

[nospark]

If the simple 2 pin E12-80 ignitor module was able to account for excessive advance/knocking then I assume it would have to be connected with the280zx ECU and then on to the coil rather than simplydirectly to the coil. The later ignitor modules had 3 pins (?) and perhaps performed this function rather than the E12-80

OR could it be that these 30 degree vacuum canisters were used in strict emission regions like California. They wanted to ensure complete burn to help comply with the regs and to hell with excessive advance

Also it might not be as bad as first appears. It only appears to give an accumulative "all in" advance when you are doing over 2800 revs (mechanical advance stays the same above this) and are cruising lightish on the throttle (less load = more vacuum). I read on a forum that at this lightish load the air/fuel mixture going into the cylinder is modest so the effect of whatever mixture being ignited very early has a less potentially damaging effect. And as an alternative thought, even maintaining a cruise at over 2800 revs might require a sufficient load such that the full vacuum advance doesn't really kick in.

All the above is guesswork on my part but asking the questions is all part of the learning process.