|
(ENGINE) Street Port / Bridge Port Question
What is it?
From my reading, a street port is a bore out of the exaust to reduce turbulence (and exhaust resistance). Is this correct? What is the expected hp advantage, and how do you get one done? (i.e. ship off the whole engine?) I have no idea what a bridge port is. Excuse my ignorance, the rex is my way of learning all the base automotive knowledge I missed out on during my own youth. |
|
Ok, I plan on buying some templates and porting my engine myself eventually, but I guess I was wrong about how to port the engine...I have noticed that the stock ports are, for the most part, cut straight through the plates. I have noticed that a street port seems to just taper off the edges of the standard port, rather than cut the port bigger straight through. Right? I have some pics here which is what got me thinking. I thought you just put the template on there, and cut straight through the plate and just make the port bigger (like if you were to englarge a hole in plywood with a jigsaw, so to speak), not taper the port into the other one? Someone please explain. Because if you are supposed to taper it into the other port, how do you know how deep to go with the taper? I read everything at mazdatrix, and it doesnt look like they do it like this, so im confused...
~T.J. PS - This picture is the standard port cut "straight through" https://www.rx7club.com/forum/attach...&postid=930347 |
|
here's a couple other good links from Mazdatrix
http://mazdatrix.com/engsp.htm http://mazdatrix.com/faq/porting.htm drew ----------- smackfu.net |
Originally posted by RotorMotorDriver I thought you just put the template on there, and cut straight through the plate and just make the port bigger (like if you were to englarge a hole in plywood with a jigsaw, so to speak), not taper the port into the other one? Someone please explain. Because if you are supposed to taper it into the other port, how do you know how deep to go with the taper? Basically, the streetport is enlarging and re-shaping the intake and exhaust ports. If you're using a template to do it, all it's going to do for you is show you the borders that you are suggested to keep within, to preserve streetability and not suck oil. When you get the borders mapped out by the template, what you want to do is try to using your cutting/grinding/sanding tool to smooth out the inner surfaces of the port so that the intake charge has a less turbulent flow into the combustion chamber of that face of the rotor. Generally speaking, you want to get the trailing end (upper left in the picture) of the port to close slightly later and/or the leading end (the lower part) to open slightly earlier, thus prolonging the intake event. For the exhaust, you want to make it wider, being careful not to make it wide enough to suck the seal through it, and gently open the top and bottom to make it open earlier and close later. The trick is getting all of these things just right so you don't have TOO much of any one thing. |
I'm not sure if I understand what you're saying here. What do you mean by "taper the port into the other one?" ~T.J. |
I think I see what you're saying now, when I started typing my response, I think you may have been in the process of posting the second picture, 'cause it wasn't there. :D
Anyway, yeah, that's the same port - just reshaped. hehehe :D |
Right...So is that what I am supposeed to do? Because the template only tells me the border of the port, not how deep or what angle and all that to make it...So how do I know?
~T.J. |
Originally posted by RotorMotorDriver I read everything at mazdatrix Originally posted by drewroman here's a couple other good links from Mazdatrix http://mazdatrix.com/engsp.htm http://mazdatrix.com/faq/porting.htm ~T.J. |
Originally posted by RotorMotorDriver Right...So is that what I am supposeed to do? Because the template only tells me the border of the port, not how deep or what angle and all that to make it...So how do I know? ~T.J. That, my friend, is an ancient Buddhist secret ... in order for me to divulge that information, you must first shave your head and spread wasabe on your chest ... hehehe :D |
No ... but seriously, though ...
I've come to find that there really is no way to tell a person how to make a port. It's something that you kind of have to have an instinct for. A lot of this stuff is going to be based on touch and how it feels in terms of making a smooth transition from it's deepest point to it's most shallow edge. My advice is just experiment on old/broken housings first and then when you feel comfortable that you've got it, then do the housing you plan to use. There is no ONE right way, but unfortunately, there are a few wrong ways. |
Well what the hell then...Anyone have some BAD housings that I can have to practice on?
~T.J. |
Ya I have a bunch and i live in WA. Have i met you before? I think i may have, whenever i go to our meets i am always in the red 74 REPU. any ways i have a bunch of old housings that i was just getting ready to throw out so if you want a couple then e mail me, jaloy@tscnet.com
PS. I live close to bremerton and i am not realy willing to haul scrap metal over to your side of the water, however i do attend the bremerton auto x on a regular basis, so next time your up here for one of those let me know. still e mail me though. CJG |
The only meet Ive ever been to was the one in Marymoore, and I say a REPU, but I think it was blue, I cant remember...He was the one that got the rotary engine model from someone here...If that was you, then yeah, Ive kinda met you. You talked to my Dad about it, and I was standing there...We came in a red GSL-SE with beat up fenders. Anyway, after I get my driveline fixed, I may be out to get them if you want to let me have them :).
~T.J. |
Oh...back to the question at hand...Can anyone show me some GOOD pictures of finished ports? Ive seen everything at mazdatrix, so nothing from there, unless you feel that I have not yet seen it please (Ive spent hours reading how-to's, and FAQ's, so I htink I saw most of it :)). I just want a good idea on what I should be shooting for...Thanks.
~T.J. |
HUGE bump...Still wondering what my ports should look like... :)
|
dude, how far are you from Puyallup? it might be worth calling Atkins just to see if they are working on one now and if you could go just to see it. when i was in Seattle, i never dealt with them, so i have no clue what they're like ... they could be cool guys or a bunch of pricks, but it doesn't hurt to call and see.
pictures don't really tell the whole story of a portjob, it's much better to see them and actually run your fingers in them (i know how that sounds :D) ... but seriously it's mostly about how smooth you make it, and staying away from the borders. also, some housings are thinner than others, so you can actually punch a hole through them if you go too deep ... but it's stuff like that that you need to know, but pictures won't help. www.atkinsrotary.com however here are some pics ... if i find more, i'll post them. http://www.pineappleracing.com/ProdSvcs.html i wish i had a scanner or that my camera was working. :cool: |
Holy shit!! Thanks DirectFreak!!
~T.J. |
Originally posted by RotorMotorDriver Holy shit!! Thanks DirectFreak!! ~T.J. |
Practicall all that is written and photograhs relate to the inlet side, not the exhaust. Which is the most critical in designing the total package?
|
Originally posted by Paul Fitzwarryne Practicall all that is written and photograhs relate to the inlet side, not the exhaust. Which is the most critical in designing the total package? Almost all opinions on the Exhaust are similar. Basically the Exhaust will be made in to a "D" shape. It's position and height are slightly changed depending on the type of port. The Intake side (as you can see) will vary greatly from the different types of port. That's why you see different types of porting, but the exhaust porting is very similar on all types. |
|
Now those are fucking ports! :D
|
| All times are GMT -5. The time now is 07:49 AM. |
© 2024 MH Sub I, LLC dba Internet Brands