Square Exaust Ports???
01-14-2003, 02:09 PM
#22
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Originally Posted by fdracer' date='Jan 13 2003, 04:48 PM
what i wanna know is why they ported it so much at the bottom? the sleeve's still there so it doesn't help w/ total exhaust flow. all they did was shorten the power stroke and they didn't even gain any flow out of it.
the reason for this is that the whole port is not open all the time. Ie. as the rotor tip sweep across the port part of the port is still blocked, so e ven when it is closing up there is lot's of surface area to continue and channel the exaust in to the sleve. As it opens the top of the port is still closed as well and it has the same effect while opening up to dump the exaust sooner.. It's like putting huge valves in a piston engine and increasing the hell out of the duration they stay open but even then they are not opn all the way open the whole time...
01-14-2003, 02:38 PM
#23
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that's true, but he's significantly reduced power by shortening the power stroke so much. the sleeve's still gonna be a bottleneck no matter how long your duration. in fact a smaller exhaust port would help in port velocity and would get the exhaust gas out faster. if he wanted more duration he shoulda delayed closing a touch and have a more reasonable opening time,instead of exclusively just hogging out the bottom. my thoughts would be to just take out the sleeve and just hog out the whole exhaust port like rice's.
01-14-2003, 11:47 PM
#24
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Pulling out the sleeve isn't a good Idea on a daily driven car, When your throwing a lot of boost in to a engine there is a ton of exaust waiting to get out so exaust velocity is not a problem. The car also probably has a huge side port so they didn't go up too far due to overlap.
But yea they did go a little low... I would have waited a few more mm's before I opened up the port.
But yea they did go a little low... I would have waited a few more mm's before I opened up the port.
01-15-2003, 10:36 AM
#25
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normally i'd agree pulling out the sleeve isn't a good idea, but the exhaust opening is already huge so he's already halfway there. rice racing daily drives his car so it's possible. i agree w/ you that there's a ton of exhaust waiting to get out, that's why i think the sleeve is still gonna hinder him no matter how big the exhaust opening is. eventually the sleeve's just gonna start stuffing exhaust back into the motor.
01-15-2003, 02:14 PM
#26
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Originally Posted by fdracer' date='Jan 15 2003, 08:36 AM
normally i'd agree pulling out the sleeve isn't a good idea, but the exhaust opening is already huge so he's already halfway there. rice racing daily drives his car so it's possible. i agree w/ you that there's a ton of exhaust waiting to get out, that's why i think the sleeve is still gonna hinder him no matter how big the exhaust opening is. eventually the sleeve's just gonna start stuffing exhaust back into the motor.
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