I did chamfer all port windows And made sure NOT to adjust them to much but i did widen and open the inside of the top port to get rid of the air pockets in the corners and increase the air velocity. It was actually a very narrow port due to the casting.Not sure if its the photo but the port on left looks wider. Also did you chamfer the edges on the ports. You don't want shape edges that will catch the piston
Well in the case of the funnel , they work off gravity so instead of vacuum so i cant see the connection between the two. If the cylinder/piston creates a vacuum that pulls air and fuel in how does it relate to me pouring fuel down a funnel?? But you may have a point with the siphon. Correct me if wrong but are you saying that by Opening the channel it may require more vacuum to increase speed of traveling fuel mixture?I am no expert, but I have opinions and they are worth double what you pay for them!
I am going to suggest "not so great". Too big.
When you pour gas into a funnel, what does it do?
Sloshes around in circles waiting to go down the tube, right?
What happens when you let your thumb off a siphon tube?
Fluid shoots out and sucks out even the last bit.
You need a more or less constant cross sectional area from the carb to port window, only ever funneling very gently. Whenever the cross sectional area opens up, the flow slows down and the fuel drops out of suspension.
So what should you do? RUN IT!
Try it. See if I'm full of bull or what.
Test it out and see how it works compared to how it was before.
What if it does work worse? You can fix it. You can build up the intake with epoxy.
Try it out first, see what you think?
Steve
Well in the case of the funnel , they work off gravity so instead of vacuum so i cant see the connection between the two. If the cylinder/piston creates a vacuum that pulls air and fuel in how does it relate to me pouring fuel down a funnel?? But you may have a point with the siphon. Correct me if wrong but are you saying that by Opening the channel it may require more vacuum to increase speed of traveling fuel mixture?
I saw this in another post and found it very helpful. It was actually the pictures i went off of during the process of porting my cyl. I figured i didnt want to take to much away but gain more control of the flow of air entering the intake. So as u can see this is what i came up with.The top port's purpose is as a guide to keep the transfers' flow symmetrical.
It needs to shoot a straight high speed jet of air across the cylinder to act as a divider and guide for the transfers' flow. So again, instead of a funnel, it should be shaped like a tube, to aim the squirt.
Here is my reedbox porting, which is only slightly widened, mostly epoxy filled:
Note the straight shot of the top port?
Also the bridge actually is fatter than at the cylinder face so it guides the flow to the center of the piston. The outer walls flare out to have a smooth fill of the interior of the piston. The whole port is a smooth guide of the flow to the window and near constant cross sectional area when the reed is in place. I run without reed stops as well, the box is filled to act as a reed stop.
Here is what the fill in looks like in red in cross section (thanks to JoeAK47 for the orig pict)
So the goals are
1) tubes instead of funnels
2) tubes aimed in the right directions
3) Near constant cross sectional area for maximum and constant velocity.
But then, I don't do this for a living, just a hobbyist.
Steve
I saw this in another post and found it very helpful. It was actually the pictures i went off of during the process of porting my cyl. I figured i didnt want to take to much away but gain more control of the flow of air entering the intake. So as u can see this is what i came up with.
You will want to port that exhaust without question. All or nothing. When you improve one area, the others become a restriction. Everything works as a team.
Hey Steve!