the only real connection i have with 1st gens is my 83 road race car... in SRX7 we are not allowed to port the cars at all so i have almost no experience with porting (except for my buddy's E-prod 1st gen).

anyway my question is... what the difference between a streetport and a bridgeport and any other types of ports there are, if any. i know, its a dumb question lol i just wanna know so i can learn from all your posts about porting. thanks

--eric

 

Check out Mazdatrix' site on Porting. It's pretty good.

 

There are no dumb questions, only dumb answers

Anyway, the mazdatrix-site inittab gave you should explain most stuff...

 

thats site is really helpful. i understand bridge and street ports.. but what do they mean by "4-port" and "6-port"??

--eric

 

There were 4 port and 6 port engines .

Actually, on the 84-85 GSL-SE with the 13B engines (probably some other engines that I dont know of also), they were given auxiliary ports that only open at a selected RPM. Kinda like secondaries on a carb, only its adding a a 5th and 6th intake port. The idea was to offer more fuel at a higher RPM and produce more power. Im not the best to explain, but I think you might get the idea. Below is a picture to kinda help illustrate it. The larger lower port is the main port, and the upper port is usually closed until a certain RPM, then a "sleeve" rotates inside, opening it to allow more fuel into the engine.



Heres a picture of the "sleeve" out of the engine. When the 5th and 6th ports arent being used, the sleeves are rotated in the egnine so the back of them blocks the ports. When the come into use, they rotate so the opening aligns with the port.



Anyway, I hope this kinda helps...

~T.J.

 

thats exactly what i needed to hear. i understand now, that helped a lot. thanks TJ

--eric

 

4 port or 6 port refers to the number of intake ports. A 6 port has 3 ports per rotor. A 4 port has 2 intake ports per rotor. In the pics above, you see the two ports on the end plate. The rotor is sandwiched between the end plate and the centerplate, which also has another port. Some people get confused and count the exhaust port. So they call a 4 port rotor a 6 port cause it has 2 intake ports (one on the endplate and one on the center plate) then they count the exhaust port.

 

No problem . Im happy I could help someone, lol

~T.J.