Spark Plug Gap with Pertronix Ignitor System

[Cordts]

What is the suggested plug gap for use with a Pertronix Ignitor system on a 69T.. TIA

[Howard M]

The Pertronix just eliminates the points. The plug gap should remain as stock. If you install a CD system like Bosch or MSD the plug gap can be increased. Don't forget to reset the ignition timing (for the last time) after installing the Pertronix.

[Cordts]

howard. thanks for the reply.. I rean the gap up to .040 and it runs real well.. I thought that with the addition of this unit that I could increase the gap..

[aigel]

What Howard said. The Pertronix does not increase the oopmp behind your spark. It just makes the job of the points a solid state, non service item. To go to a larger gap, you'd need a more powerful spark, i.e. from a more powerful coil.

That said, the later cars have a pretty small gap too.

George

[Cordts]

Ok, that said.. I have the large Accell coil and Im running that big gap on this,, is that ok? I read some posts where I thought that a gap that big would not work,, maybe that was just with regular points..

[kucharskimb]

cordts
nice car.

you're not going to get a definitive answer off of this board about this. it's black magic voodoo to most.

determine the resistance of your ignition wires and coil, then call the manufacturer. give them all the information available. then see what they recommend. petronix does a lot of kits specifically for VW. they will have the answers you need. (909) 599-5955

if the gap is too large and the plug wires have too much resistance, then the intended spark energy may find the path of least resistance. ie you may get arcing between wires or between terminals in your distributor. some ignitions recommend low resistance wires and low resitance coils (which you have changed). beru wires are relatively high resistance. a final test is to run the vehicle in a blacked out area and look in the engine bay for stray arcs throughout the rpm range.

i run a crane xr300, ps91 coil, jacobs wires, ngk platinum and open the gaps to .045". all based on manufacturer recommendations.

[Cordts]

Kuch - Thanks.. will do.. Here to "Black Magic VooDoo" my friend..

[Zeke]

I'm going to bounce a theory off the wall for G&G and to actually be corrected by the ones that really know this stuff.

One thousandths gap for every 1000 volts with a minimun of .023 and a max of .060.

[aigel]

Generally, I would err on the small gap side and go with stock for your application. You will have reliable spark every time. What is the benefit of a larger gap? Will your mixture ignite twice as well, if your spark is twice as long?

George

[kucharskimb]

hey, Kuch was my call sign...

[randywebb]

check out the spark gap info from Steve Weiner/Wiener on his web site

http://www.rennsportsystems.com/

[kucharskimb]

from Rennsportsystems.com:
The other big drawback is that you cannot use spark plug gaps larger than .032 without misfires. Its well proven and documented that plug gaps in the .040-.045 range make more overall power and result in better idle qualities due to the larger flame kernel and the resulting more thorough combustion process.

slightly ambiguous, but i think he is saying you can only go to .032" with a stock system. he lists several aftermarket systems in this writeup. it's my understanding that with one of the aftermarket setups, .040-.045" is optimal.

so i called steve... he agreed. with aftermarket ignition and matching coil and wires, .040-.045" is fine.

comments?...