Kawasaki VN750 Forum banner

1 - 8 of 8 Posts

·
Heading to the DARKSIDE!
Joined
·
177 Posts
Discussion Starter #1
What do think was the reason for the design of two plugs per cylinder? More Power.......or to burn better for emissions? Also do our coils only fire on power stroke or do they also fire on the exhaust stroke too.......Like all distributorless car ignitions do?
 

·
Registered
Joined
·
686 Posts
What do think was the reason for the design of two plugs per cylinder? More Power.......or to burn better for emissions? Also do our coils only fire on power stroke or do they also fire on the exhaust stroke too.......Like all distributorless car ignitions do?
Manual says Suck Squeeze Bang Blow...guess that means traditional 4-Stroke :smiley_th
 

·
Super Moderator
Joined
·
11,970 Posts
The double plugs per jug is not really for power per sae, but to insure a complete combustion.... Likely to pass EPA emmissions.


Spark plug placement, head shape as well as the angle of the valves can all have an effect on how the mixture burns....as well as how much power the motor puts out.

I saw a film on MV Augusta's factory, and one of the engine designers showed how just changing the angle the intake valves 1.2 degrees added almost 2 hp.

KM
 

·
Dual Sport idiot
Joined
·
24 Posts
What do think was the reason for the design of two plugs per cylinder? More Power.......or to burn better for emissions? Also do our coils only fire on power stroke or do they also fire on the exhaust stroke too.......Like all distributorless car ignitions do?
Without a cam position sensor it has to be a wasted spark, the ignition only knows where TDC is, not which stroke it's on.
Oh, and not all distributorless ignition systems fire on the exhaust stroke, most coil on plug systems do not.
 

·
Premium Member
Joined
·
369 Posts
Both plugs fire at the same time. With two plugs the mixture burns faster. If you want to burn down your house, it is faster if you start the fire in multiple corners.;)
 

·
gun slinger
Joined
·
1,110 Posts
Both plugs fire at the same time. With two plugs the mixture burns faster. If you want to burn down your house, it is faster if you start the fire in multiple corners.;)
:smiley_thi
 

·
Registered
Joined
·
748 Posts
The double plugs per jug is not really for power per sae, but to insure a complete combustion.... Likely to pass EPA emmissions.


Spark plug placement, head shape as well as the angle of the valves can all have an effect on how the mixture burns....as well as how much power the motor puts out.

I saw a film on MV Augusta's factory, and one of the engine designers showed how just changing the angle the intake valves 1.2 degrees added almost 2 hp.

KM
Pull just one plug wire off one cylinder, and you'll notice the power loss; pull one off each cylinder, and you'll _really_ notice it...
 
1 - 8 of 8 Posts
Top