i saw an SS on ebay that had (2) dual outputs coils and had both wires going into a single spark plug per coil (non-DS bikes). i understand that producing a hotter spark would have a more efficient burn, but has anybody else know about using this set-up?
here's the pretty sexy bike for a visual aid.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=130507568750&ssPageName=STRK:MEWAX:IT (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=130507568750&ssPageName=STRK:MEWAX:IT)
Quote from: Düb Lüv on April 13, 2011, 05:50:42 AM
i understand that producing a hotter spark would have a more efficient burn,
It may or may not - it's a kind of contentious issue.
That is a make the beast with two backsing sexy SS
A hotter spark may give you a tiny edge as it will ignite fuel slightly faster. Compare tossing a match onto a pool of gasoline vs tossing a wood torch: they both go to flame fast, but if you could see it, the torch would make it go a little faster, perhaps milliseconds.
A dual spark produces a larger flame front in the cylinder, a hotter spark using the same plug would burn the plug out faster. Dual spark has a definite advantage. Instead of a "hotter" spark, you have a "larger" spark and that allows for more fuel to be burnt.
Personally, I don't see the advantage of a "single spark, dual coil" design. It would be easy enough to implement on a race bike, and the fact that NO ONE uses it probably means there is no advantage.
the one in the ebay listing had been converted to dual spark. so it had its heads modified to take the second spark plug. Ducati-kaemna does that as well.
Quote from: Raux on April 14, 2011, 08:21:01 AM
the one in the ebay listing had been converted to dual spark. so it had its heads modified to take the second spark plug. Ducati-kaemna does that as well.
did you ask him? cause there's no plug wires on the clutch side unless they're hidden and what looks like 2 plug wires going into the vertical spark lug boot.
well the listing says 'dual spark' so that's the only way to do it
this is from Kaeman.. probably why you can't see it
(http://www.kaemna.de/pic/katalog/795detail1.jpg)
In the third photo, you can see TWO wires going to the vertical head spark plug.
(http://i.ebayimg.com/00/$%28KGrHqZ,%21loE2EvWzpy%21BNoj8wsUew%7E%7E_12.JPG)
yeah saw that.
sending double the voltage to a single sparkplug hoping they hit at the same time?
Most likely with a dual head coil it will spark at the same time. I just question the efficacy of it.
I emailed the seller, here's his reply:
QuoteEach head has 2 plugs, 4 wires. You have to remove the lower and Carbon belt cover to see the other two.
So it's just a dual spark setup and the spark wires have TWO leads from each coil terminal.
so it's just like the picture i put up from Kaemna.
each head has 4 wires? so he has 4 dual output coils?
No just two coils. Each coil terminal has 2 wires.
yeah i figured... just hate when people write vague sentences.
"Each head has 2 plugs, 4 wires."
Gotta say, wish the factory did it that way instead of through the front of the timing belt cover, much tidier.
If I ever do this mod on my 900, I now know a cleaner way.
Nice SS.
veetwo did plenty of dual spark setups as well.. when dyno'd it showed little difference in performance. So not really worth the cost.
I think ducati did it more for emmisions...
Funny thing is I think the new Evo motor is back to single spark.
Very true.
Maybe more compression and better combustion chamber design lets them get away with one plug.
Hard to have more than one plug on a 4 valver
Quote from: ducatiz on April 15, 2011, 04:15:08 AM
Hard to have more than one plug on a 4 valver
2011 Ducati Monster 1100 Evo = 2 valver ;)
Ah. I was thinking of the 848 evo
perhaps cost reduction for new 1100 evo motors