z8cw

for the intake port seems to result in 120% VE between 5k to 6k rpm according to a Mazda tech paper. It doesn't say anything about the paired up exhaust port. Anyone has any info on that. Also can someone help with where a peripheral port would be on the rotor housing achieving these numbers.



Thanks

CW

kahren

i am pretty sure that VE is based on their MFR housings and those have a port timing of intake open 86° BTDC and close 75° ABDC. the VE varies with little changes so it matters what parts you choose for the setup you are goign to run.

z8cw

attached is the article, though I am looking for more info.

z8cw

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attached is the article, though I am looking for more info.

z8cw

**** one more try...



port paper



you have to be patient, it is a very slow server

j9fd3s

more info for what? that port timing works on a pp motor, but it may not be so hot on a side ported engine.

z8cw

What are you saying? We try to make our engines breath. That will make power. So, who cares what port, side or peripheral. The paper compares side, peripheral and combined, which will translate into a bridge if I am not mistaken. I am trying to find more info on exhaust ports and possible someone can just give me the corresponding mm up the rotor housings for these intake degrees.

kahren

peripheral ports have much earlier open timing then the side port does.

its very diffrent as for as both of those styles are concerned. the bridge port has an even earlier opening time then a peripheral port.

z8cw

It depends on your porting, doesn't it. You can make a bridge tiny and a PP huge, so I really don't agree whith what you are saying. This paper illustrates effect of different intake opening and closings, so I found this very interesting. It seems actually tested not theorised like so many other post on message boards.

kahren

where the bridge port is located determines when it opens, on sideport engine depending where you place your bridge and how tall it is up and down determines its port timing. unless the bridge is only about half the length up/down wise and is on the top side, then its timing will match the pport open timing, relatively speaking. there isnt TOO much timing to paly with as far as power is concerned, when you are revving within the limist of the engine (under10k). you only make most power with the timing tuned in. the bridge port would not make much power if its only half of what it should be. a bridge is still a side port, and the air does not directly fall into the combustion chamber so filling of the chamber is not as high as it can get with a pport. so what i am trying to get at is, if you port the bridge to imitate the timing of the pport you will not be makking the power you will be with the same port timing as the pport (and beign off not by a small amount) the bridgeport is at such a locating where it is hard to get air going thru there, so its not as simple as making a hole and having the air magicly flow thru there. that is why you see a lot of the engine builders try to maximize the flow thru the bridge at porting with diffrent styles that they assume will flow best thru that opening.