Wasted spark

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mk e
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Re: Wasted spark

Post by mk e »

Circlotron wrote: Tue Mar 20, 2018 8:00 am
mk e wrote: Tue Mar 20, 2018 7:06 am .....and the power. Waste spark uses double the power, I never really thought about that be my v12 project that needs 2 20A circuits to feed the coils instead of 1 because twice as many are firing.
Half as many coils, each firing twice as often.
What’s this twice the power bizzo?
With COP options.
Mark
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Re: Wasted spark

Post by user-23911 »

mk e wrote: Tue Mar 20, 2018 7:06 am

....and the power. Waste spark uses double the power,
Why would it use double the power?

It doesn't.
The energy goes to the plug that needs it.
The loss a cross the wasted plug is minimal.


If anything it's far superior because it keeps electrical noise out of the rest of the electrical system.
Unlike a conventional coil where the return path for the spark current is through the battery and everything connected to it.
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Re: Wasted spark

Post by Truckedup »

GLHS60 wrote: Tue Mar 20, 2018 5:04 pm Neon 2.0L Engines with wasted spark are fussy about spark plugs.

A Platinum plug on the "reversed polarity" end of the coil can cause misfire and even backfire.

Thanks
Randy
You need a double platinum plug.................
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Re: Wasted spark

Post by user-23911 »

Double platinum (or iridium) plugs are essential with wasted spark.They're also best for normal ignition systems due to the sharp point which requires less voltage to fire the spark.
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Re: Wasted spark

Post by NORSK »

Allright,after a full day of swearing,machining and testing i managed to make a trigger whhel and a cam sensor holder
So no waste spark this time
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Re: Wasted spark

Post by Geoff2 »

My 1938 Harley used a wasted spark system & used std spark plugs, loooong before Plat or Iridium plugs were invented...
Circlotron
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Re: Wasted spark

Post by Circlotron »

Geoff2 wrote: Thu Mar 22, 2018 4:53 am My 1938 Harley used a wasted spark system & used std spark plugs, loooong before Plat or Iridium plugs were invented...
Being a V twin and not an in line twin, when the rear cylinder fired on the compression stroke the front cylinder would have been 10-30 deg past TDC and so already on the inlet stroke. How come then the front cylinder didn't misbehave???
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Re: Wasted spark

Post by cjperformance »

Geoff2 wrote: Thu Mar 22, 2018 4:53 am My 1938 Harley used a wasted spark system & used std spark plugs, loooong before Plat or Iridium plugs were invented...
Kawasaki Z900(the 70's ones not the modern version ) just to name one of the many more!
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Re: Wasted spark

Post by digger »

I'm using "standard" plugs with wasted spark, it has worked well for last 4years. ive never notice accelerated erosion
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Re: Wasted spark

Post by cjperformance »

digger wrote: Thu Mar 22, 2018 6:47 am I'm using "standard" plugs with wasted spark, it has worked well for last 4years. ive never notice accelerated erosion
I use standard plugs with wasted spark all the time, petrol (gasoline), LPG, with or without boost on either fuel. Never a problem.
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Re: Wasted spark

Post by Truckedup »

cjperformance wrote: Thu Mar 22, 2018 6:35 am
Geoff2 wrote: Thu Mar 22, 2018 4:53 am My 1938 Harley used a wasted spark system & used std spark plugs, loooong before Plat or Iridium plugs were invented...
Kawasaki Z900(the 70's ones not the modern version ) just to name one of the many more!
Nearly all or all Japanese inline 4's use or have used a wasted spark ...My Ducati 900 (90 degree two cylinder) has two coils and two separate ignition pick ups on the flywheel...But each coil fires every 360 degrees....
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
Circlotron
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Re: Wasted spark

Post by Circlotron »

Circlotron wrote: Thu Mar 22, 2018 5:45 am
Geoff2 wrote: Thu Mar 22, 2018 4:53 am My 1938 Harley used a wasted spark system & used std spark plugs, loooong before Plat or Iridium plugs were invented...
Being a V twin and not an in line twin, when the rear cylinder fired on the compression stroke the front cylinder would have been 10-30 deg past TDC and so already on the inlet stroke. How come then the front cylinder didn't misbehave???
Got front and rear cyls swapped!
When the front cyl fires just before tdc on the compression stroke the rear cyl fires quite a few degrees past tdc on the start of the inlet stroke. Why no kaboom?
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Re: Wasted spark

Post by mk e »

Circlotron wrote: Thu Mar 22, 2018 9:00 am
Circlotron wrote: Thu Mar 22, 2018 5:45 am
Geoff2 wrote: Thu Mar 22, 2018 4:53 am My 1938 Harley used a wasted spark system & used std spark plugs, loooong before Plat or Iridium plugs were invented...
Being a V twin and not an in line twin, when the rear cylinder fired on the compression stroke the front cylinder would have been 10-30 deg past TDC and so already on the inlet stroke. How come then the front cylinder didn't misbehave???
Got front and rear cyls swapped!
When the front cyl fires just before tdc on the compression stroke the rear cyl fires quite a few degrees past tdc on the start of the inlet stroke. Why no kaboom?
It is a problem with that setup. I used to race a H-D back in the 90s and switching from waste spark to single fire added a few % more HP.
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Re: Wasted spark

Post by digger »

cjperformance wrote: Thu Mar 22, 2018 7:30 am
digger wrote: Thu Mar 22, 2018 6:47 am I'm using "standard" plugs with wasted spark, it has worked well for last 4years. ive never notice accelerated erosion
I use standard plugs with wasted spark all the time, petrol (gasoline), LPG, with or without boost on either fuel. Never a problem.
I didn't like the idea of paying 5x price for plugs when I'd never practically get the cost benefit on something that does relatively low mileage
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Re: Wasted spark

Post by user-23911 »

The whole idea behind platinum plugs is that they've got sharp points on the electrodes.
Sharp points give a better spark at the same voltage or the same spark at a lower voltage or any combination between.
The important part is a sharp point.
Like a needle.


It won't happen with copper because it's too soft / not dense enough / melts too easily, erodes too quickly.


With platinum plugs, they'll last 100.000 miles so long as the engine doesn't fail first due to failed modifications.
A copper plug won't.
The tips melt and erode and if you COULD make a copper plug with a sharp point(you can of course?)it wouldn't last very long at all.


Sharp points always give a better spark.
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