Unstable RPM during carb tuning

[dogshome]

All good 

Measurements anticipated 

I'm not sure why our brains deterioate after 18 years or so, it seems a complete waste since we live to (fill in latest speculation here) (around 90) and it can't all be crammed in that time. Mr Darwin was right and I hope we override him in the future i.e we each hit our own wall and someone else puts a hole in it. Which is a really good thing. The trouble is my depleting cells can't add it and it just gets lost. I suppose if the collective knowledge becomes singular, then that might be a very dangerous thing - in the the wrong hands / brain.

So yes, interested in what your 'scope shows, since I haven't reached an override yet 

[mrclubike]

Sorry about not getting back sooner
Needed a new Battery  and I waited until I had it apart to test the current draw
So
It appears shorting the secondary makes little difference on primary current draw
As a matter a fact it pulls slightly more when it is running than it does during cranking with the plugs shorted
About the only difference is saturation time
FYI
This is not a stock Bosch system
It is has the standard bean can but I am using a 1.5 ohm Dyna coil and a GM Delco HEI ignition module (used in 74 and on GM cars and trucks)

The first screen shot is
ignition on
coil powered up
not cranking
both secondary's  grounded
Thats about 4.4 amps
According to Ohms law the ICU must be current limiting
I know if I install a ,7 ohm coil the Icu gets hot
Thats why I went back to a brown coil 

[mrclubike]

This is cranking
both secondaries grounded
 No higher amp draw
You will notice the saturation slower than when one side is making spark as in the next picture

[mrclubike]

here is one side shorted one side sparking under compression

[mrclubike]

And finally just idling
Both cylinders firing

[dogshome]

Thanks for the full report. You promotion will show in your paycheck at the end of the month 

Can't find a definitive spec sheet, but from http://nebula.wsimg.com/5956cdbfbf7fc2e9bc4c33682dbb7427?AccessKeyId=967E22DE049163134A29&disposition=0&alloworigin=1

But that is not all that the HEI module does. The
HEI module electronically limits the peak coil current to around 6 Amps,

It also makes other adjustments to dwell, so the fact that nothing has gone 'bang!' on your custom system is expected. The stock electronic switch I am sure is not intelligent and is likely to draw strange currents and indeed follow in Mr Fawkes plan.....

?

[Barry]

Can't find a definitive spec sheet, but from http://nebula.wsimg.com/5956cdbfbf7fc2e9bc4c33682dbb7427?AccessKeyId=967E22DE049163134A29&disposition=0&alloworigin=1

Fascinating article on the HEI module.   You have to wonder why aftermarket electronic ignitions are so expensive when something as cheap as a HEI module can do everything needed.

[mrclubike]

Can't find a definitive spec sheet, but from http://nebula.wsimg.com/5956cdbfbf7fc2e9bc4c33682dbb7427?AccessKeyId=967E22DE049163134A29&disposition=0&alloworigin=1

Fascinating article on the HEI module.   You have to wonder why aftermarket electronic ignitions are so expensive when something as cheap as a HEI module can do everything needed.

Unfortunately I do not get all of the benefits the HEI has to offer because i am using the hall sensor instead of the reluctor that the HEI normally uses
The main one is the longer dwell at higher RPM and the fact the coil will power up when the engine is not turning
That is why I have to stay with the 1.5 ohm coil 
I need to get at rid of the hall and figure out how to mount the reluctor in the can