Re: equalizing vacumn
Maybe I am looking at this wrong but it seems to me it is NOT a mechanically sound idea and here is why.
First you really cant "equalize vacuum because only one cylinder at a time is on its intake stroke and normally it is only pulling on its carb (below 6k rpm). Now we are opening up that intake, which is below the carb, to all the other intakes and carbs???
On a carbuerated bike the only thing that moves air/fuel into the cylinder is the difference in pressure between the float chamber(atmospheric pressure) and the venturi affect at the throat. The fuel doesnt get sucked in, it gets pushed in by the air rushing through trying to fill the cylinder as the piston travels down.
Now opening that intake to more area (tubing and other intakes is going to allow that pressure through the carbs to travel to places other than the intakes valves and to the cylinders. It is going to take the path of least resistance. It will lower the VE of that carb.
Plus the only time any cylinders are on their intake stroke together is #1 & #4 during the last 70* of #4 intake stroke #1 is starting to open. You can see that here
http://vmaxguru.com/Tech/Gen1/Pages/Ignition/Ign_Sreadsheet.bmp
Now it might actually help with the timing because you are smoothing out the pulses seen by the vacuum advance. Instead of seeing vacuum once every 720* it will now see it once every 180*. Not going to give it any more or less timing but allow it to work more smoothly.
So in summary
1. You really cant "equalize" vacuum when the cylinders dont overlap except as noted above.
2. You are giving the pressure/vacuum other places to go other than into the cylinder lowering VE.
I appreciate any feedback on my thoughts
Cheers
