Multiple Spark systems, Mallory, Permatune with DJET??? Options

[Krieger]

I have been running the same MSD 6A box for 8 years with the stock points and Djet. Works like a charm and have only adjusted the points twice. Simple and effective. I too have had a pertonix failure-in fact it was only hundreds of miles after I got the car running. The D jet is irrelevant, but you must buy the "tach adapter" for the tachometer to work. I run this on my 2270 with a stock rev limiter. A few years back my car barely passed smog WITHOUT the catylytic converter and just the airpump on. I think thats pretty clean. I bought a 6AL box for my 3.0 six. Call JEGS/Summit they got it all. I used the MSD wires too.

[Gint]

When I use a pertronix, I keep a known good distributor in the trunk all set up and ready to go. One 11mm wrench, a little timing by ear and you're back on the road again and on your way home to the garage.

A condensor may have...but not points unless the contact fell off the point...then you really should have looked at them a bit sooner.

You keep a whole petronix and distributor in the trunk? So you have two petronix systems??? lol
Points fit in my glovebox....

Rich

Now that would be stupid. I'll clarify. Dizzy loaded up with points and condensor. Do whatever you want, but I personally don't like fiddling with points and I sure don't want to do it on the side of the road. A distributor will fit in your glove box too. (IMG:style_emoticons/default/wink.gif)

Truth be told it was the distributor with screwy contact plates that caused the points rubbing block to wear down to a nothing. I ended up replacing the whole damn thing. With guess what? A dizzy with a Pertronix installed.

I'm done. To each his own.. (IMG:style_emoticons/default/beerchug.gif)

[ericread]

I know that everyone seems to be tiring of this thread, but just one more question...

Please explain to me the value of the multiple spark system. My understanding of ignition is that the timing of the spark is very important to the correct operating of the engine. Too early and you lose compression quality of the piston downstroke, too late and you lose the the quality of the fuel/air mixture (or some such stuff - I have no doubt someone will correct this with a better, more correct description). So with a multiple spark, aren't you risking late ignition of some of the gasses. And wouldn't the value of catching these un-ignited gasses only be valid in the case where the original spark is not firing correctly? And do you really want a late ignition to occur?

It just seems to me that if your spark plug is providing a correctly timed spark, there would be little to be gained by the multiple spark system (IMG:style_emoticons/default/confused24.gif)

Sorry for all the questions, but thanks in advance for your reply.

[TravisNeff]

A lot of those sytems ignite for 30 degrees of crank rotation to help ensure a complete burn. Multiple sparks at lower rpms. How much power/efficiency do you lose to a misfire or a partial burn? I do see erics point of a misadjusted ignition.

I finally passed my emissions test today after the 5th test and that was due to unburnt fuel at idle. I can see where a multi spark box can help address that issue.

[jasons]

A lot of those sytems ignite for 30 degrees of crank rotation to help ensure a complete burn. Multiple sparks at lower rpms. How much power/efficiency do you lose to a misfire or a partial burn? I do see erics point of a misadjusted ignition.

I finally passed my emissions test today after the 5th test and that was due to unburnt fuel at idle. I can see where a multi spark box can help address that issue.

Travis, just get a classic car insurance policy, then you are exempt. NO MORE EMISSIONS!

[TravisNeff]

You are right on that, but I have to prove that I pass emissions first- shoulda coulda dunnit last year though.

[jasons]

You are right on that, but I have to prove that I pass emissions first- shoulda coulda dunnit last year though.

I don't think so. Our vette failed and I got it registered. I took my policy binder in to the DMV and renewed it in person, no problem. I didn't even have to test the vette, but I wanted to see how it would do because I suspected it was rich at idle. And, I was right. But, I still registered it without making it pass.

Taking a 914 to emissions is probably the most painful experience. The monkeys can never shift the car right. Finally, I got the guy to start the car in 2nd and leave it in 2nd. That was the only way I could get a good test.

[r_towle]

I know that everyone seems to be tiring of this thread, but just one more question...

Please explain to me the value of the multiple spark system. My understanding of ignition is that the timing of the spark is very important to the correct operating of the engine. Too early and you lose compression quality of the piston downstroke, too late and you lose the the quality of the fuel/air mixture (or some such stuff - I have no doubt someone will correct this with a better, more correct description). So with a multiple spark, aren't you risking late ignition of some of the gasses. And wouldn't the value of catching these un-ignited gasses only be valid in the case where the original spark is not firing correctly? And do you really want a late ignition to occur?

It just seems to me that if your spark plug is providing a correctly timed spark, there would be little to be gained by the multiple spark system (IMG:style_emoticons/default/confused24.gif)

Sorry for all the questions, but thanks in advance for your reply.

There is alot of unburnt fuel in our aircooled motors that gets wasted.
Its a factor of the head design and the location of the spark plug and the chamber design, along with the piston design.

This type of system shoots off multiple sparks that will ignite more of the fuel and create a more efficient burn on each stroke.
The spark is also hotter if properly installed with new wires.
Because the spark is hotter, more voltage is going to the plug.
You can run colder plugs and you need more of a gap...well you can use more of a gap. Its a bigger spark.

The idea behind this is to burn more of the fuel in the chamber instead of pushing it out the exhaust into the atmosphere.
The results are more power per stroke.

Rich

[ericread]

There is alot of unburnt fuel in our aircooled motors that gets wasted.
Its a factor of the head design and the location of the spark plug and the chamber design, along with the piston design.

This type of system shoots off multiple sparks that will ignite more of the fuel and create a more efficient burn on each stroke.
The spark is also hotter if properly installed with new wires.
Because the spark is hotter, more voltage is going to the plug.
You can run colder plugs and you need more of a gap...well you can use more of a gap. Its a bigger spark.

The idea behind this is to burn more of the fuel in the chamber instead of pushing it out the exhaust into the atmosphere.
The results are more power per stroke.

Rich

Rich; Thanks, this is starting to make sense. However, I still do not understand a hot spark versus a cooler spark. My understanding is that our 914s should run a cooler spark. If we run a hotter spark, do we compromise the fuel burn in the cylinder? And does a hotter spark mean a shorter spark period?

Again, my thanks.