RX7_TT

Ok, well i have been reading on this site for some time and i joined a while back. So far i have made very few posts, rather i have been spending time learning how things work. I'm quite versed in how a piston powered internal combustion engine works. I'm learning slowly how the rotary style works.



But now i have questions about it. I figured this would be the best place to ask seeing as im a noob and i bet most all rotorheads know this already but here goes.



I was reading an article on exhaust porting, and about how it is important to return the edge of the port to the factory style bevel. This will increase apex seal life and what not.



But my question is in regards to how much you would take off of the port to make a difference.



I'm currently looking at getting a 1995 RX7, but the only way i can get one is with a blown engine. So i will need to do most of the rebuild myself. Now im interested in doing a port job but im warrie about removing to much material.



So heres the questions,

What do you use to remove the material?

How much material do you remove for each stage of port? (ie, mild street port, aggressive street port, ect.)

Is it a far assumption that i can do this with the aid of rotorheads like the ones on here?



I have most every tool at my disposal due to the fact that i spend most of my spare time repairing and selling cars. I'm currently trying to get my second year apprenticship at a good shop. Preferably Staff's Automotive (www.staffsauto.com), or at Eunos (www.eunos.com).



I appreciate any help on this topic and really appreciate all the information you have to offer on this grate site.

RX7_TT

This is a quote i pulled from another post on porting. Now the question i have here is why would you port the secondary side housings more than the center housing ports?



Could someone explain the difference between the secondary side housing and the center housing?



Thanks a bunch guys, its really appreciated.

7mech

Well first I think this needs to be moved to the porting section.



You'll need to use an air powered die grinder to remove the material with a carbied bit and some sand paper bits.



You can buy templates to use to show how much to remove. Try racingbeat.com or mazdatrix.com. Both of those websites sell porting templates.



You can get plenty of advice from us or you can just send your housings off to be ported. If your going to do it yourself make sure you practice first on some old housings and get an experienced friend to help you with the porting.

7mech

I'm not sure but I believe that you would port the primaries smaller for more low and mid range power and the secondaries larger for more top end power.



The secondary ports are on your rear and front end plates and your primaries are on you center(intermediate) housing.

7mech

Hope all that helped.

RX7_TT

That helped greatly. Ill have to check out the sites you recommended. Oh and im sorry if i posted it in the wrong section, just thought this was a noob question, cause it seems like there are a lot of guys in here that really know there stuff.



Thanks a lot 7mech

7mech

That's cool. Even if it's a noob question it's still about porting therefor it belongs in the engine building and porting section. Anyways you might want to check out that section for more info on the subject.

Sinful7

Off we go to the porting setcion!

7mech

Thanks man. Hopefully these guys can give him better info than I.

kahren

why do u want to port, it all depends on what u want out fo your engine. the 93-95 motors had pretty good ports to begin with. tell us what your goal for this car is and what power or 1/4 mile time uare lookign to get and i am sure peopel will eb abel to help you better. check out teh stickies in this forum.