Port timing

gary55

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Street Ryderz

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Thanks Stoneman. That's not not what I was huntin after. The trans. ports these days already have a bit of a dam on the exhaust side directing the charge. What is shown here is pretty old castings. I was wondering if back cutting and funneling from case to window was what Ryderz was up to.
Actualy Gary is right in that the window is the last choke(restricted)area of the positive pressure being pumped up the transfer,If you look at the pic here the transfers at the base are bigger than the case area that directs the charge,Some are worse than others depends on the casting though all seem to be misalinged somewhat,So I match this area to align properly and reduce turbulance witch affects the constant pressure.The transfer area (track)before the window(port) is enlarged slightly where the back cut is done but that area is tappered in normaly and smaller in area than the lower portion of the track,So the funneling or choke point starts there instead of the window itself and that little bit of pressure change causes a lower pressure in the area ahead of the lip that is close to the exhaust port this can be seen with the water test the stream will actualy curl around that edge.My concern is that alot of the charge volume was lost due to this especaily at lower rpm where the return wave is mistimed and not bringing it back to the cylinder,The back cut allows the angle to be matched to the intake side wall and cut the lip flush to the new angle of the wall,Looking at the pic below you can see that both walls (sides) are basicly the same angle now and the area infront of the window is now the same volume of the track so the pressure is more constant and the flow directed out more evenly and toward the center of cylinder trapping more charge.
 

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FurryOnTheInside

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I couldn’t make heads or tales of what that says...
I think he said if you are watering the garden, and you put your finger over the end of the hosepipe a bit, it directs the water and appears to spray faster; but we know it reduces the flow because we see that when we step on the middle of the hosepipe that's on the grass. And transfers are like the garden hose.. they need to be open and smooth from the end that's actually part of the case all the way through to the window into the bore. :)
 

FurryOnTheInside

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So once we have done the transfer redirecting mod without narrowing down the window with JB Weld, we can make use of the case matching mod.
Perhaps this is even achievable without splitting the case? :)
Can we use a chunk of putty to literally get an impression of how the case and jug are mismatched? o_O
 

Street Ryderz

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So once we have done the transfer redirecting mod without narrowing down the window with JB Weld, we can make use of the case matching mod.
Perhaps this is even achievable without splitting the case? :)
Can we use a chunk of putty to literally get an impression of how the case and jug are mismatched? o_O
I've never done it with the case together,I'm a little O.C.D. when it comes to these lol I'm allways thinking that one little unseen fileling could destroy all the effort put in but that's just me!If you sealed it up good and flushed it out after should work I guess.For me it's not a big deal to split the case for the peice of mind gained.
 

6blueoval9

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I'm not thinking you have to fill the port with a ton of jb weld to get the air flow changing direction on the bad side....I'm personally going to try just enough jb weld the height of the window only....I'm thinking as long as you smooth any sharp or abrupt edges where you added it, a cfm loss is minimal at best.

Still havent done this yet but I certainly will give it a shot.
 

Street Ryderz

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I'm not thinking you have to fill the port with a ton of jb weld to get the air flow changing direction on the bad side....I'm personally going to try just enough jb weld the height of the window only....I'm thinking as long as you smooth any sharp or abrupt edges where you added it, a cfm loss is minimal at best.

Still havent done this yet but I certainly will give it a shot.
A loss is a loss when were trying to make gain's it doesn't make sence to me to accept a little loss here and there that all add up when it can be corrected but that's me as I said I think I'm a little O.C.D. when it comes to engines lol.
 
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