> Does anybody have any experience with this?
>
> Does anybody know if this will actually give more horsepower?
There was a kick-ass article in the BMW Motorcycle Owners Association News
some months back about the engineering work that went into the design
of their "new" twin-plug R1150 engine. It pretty much dispelled the view
that there is *ANY* gain in performance from multi-firing a plug, or from
firing a second plug in the same "concentric circle" measured from dead
center of the piston as the first. Had to do with flame front propagation
and how combustion actually happens, all that jazz.
Since I've fooled around with this sort of thing for a long, long time,
I found it to be very worthwhile reading.
My own experience with MSD et al is that what it's REALLY good for is
keeping the plug from fouling while you're doofing around the pits. That's
pretty much it. Now, that is NOT an insignificant gain, but when you read
the fine print you discover that the multiple firing goes to zero as
the R's cross some magic number, 3500 I think...
Your milage may vary. But I gotta take my hat off to those BMW boys,
the new engine *rocks*... and I'm giving thought to adapting their
twin plug design to my other favorite air-cooled engines...
Stan Hanks
Portland OR
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