I have searched the forum but I couldn't find a thread which in a simpel yet comprehensive and complete way explains the basics of porting, e.g. what is "street porting", "bridge porting" etc.

I am sure this has been discussed many times, thus could anyone direct me to some informative threads dealing wiht this topic.

BR, Bo

 

http://www.mazdatrix.com/s.htm

This page has pictures and an explaination of some of the different types of portings.

 

firstly great to be registered on a new rotary club site..thank-you, to all... have a look in the porting section of badrotor.co.nz, but i will contribute plenty of tech info , as i brouse through the site.. thanks

i see corner seals as no hinderance...

 

New? 7 years old is hardly new

 

Some would describe porting as an art. Basically, the goal of it is to create a positive "swirl" of intake charge within the combustion chambers, to allow air to more easily (and thus decreasing necessary boost, even for a non-turbo), and to tune your HP ( or torque) peak.

This is a thread that I found to be particularly informative and strangely innovative https://www.rx7club.com/showthread.p...hreadid=212537

Maybe this will better help on your porting endeavor(s). Point of advice: Get REALLY good with a grinder before you go cutting on your good housings, or else the grinder will jump out of the port and walk all over the surface of the housing. Also, lumpy ports = lazy ports. I polish mine to a 320-grit finish. On the 6-port motors, when I got all crazy, I used a wire-feed MIG welder to make an "air ramp" on the 5/6 ports (and it worked very well I might add, save NO bottom end power, but who cares; they're MY RACE ports!); sort of an integrated "pineapple sleeve" if you will. Oh, and if you decide to weld in some air ramps, use welder's tape (aluminum tape) to protect the ENTIRE housing, or else it'll have splatter all over it. Use low heat (amperage) too, because if you don't, it'll just disentigrate the housing.

I've given away enough secrets for today....

Matt