Hey sup guys. I am building a non turbo 13b. I have ported gsl-se housings that are ported and notched for bridgeporting. The motor had 6 port streetport irons on it before I blew it. I was wondering if 4 port or 6 port could generate more power? Can put a big bridgeport on a 6 port? Basically give me the run down on power potential between 4 and 6 port. If I switch to 4 port do I need to change eccentric shaft and all other parts from a 4 port?

 

on an n/a go 4 port,its better and thats why mazda made it that way

 

What?
Mazda made NA's 6-port, not 4 port.
The 6-port was to improve driveability and overall power, but I'm honestly not sure which one is better once you get into bridge porting.

 

my bad man haha i knew that just a brain fart haha and thanks for catching that

 

You already have a lot more port volume with the 6 port, but the runners arent ideal if you plan on removing the sleeves.

 

Your GSL-SE housings have grooves for the water jacket o-rings.

2nd gen style irons have the groove for the water jacket o-rings.

See the issue?

You can apply the same style of porting to 6 port irons that you can on 4 port. When bridgeporting, the result is the same so use whatever irons you want.

 

So I cant use gsl-se housings with 2nd gen plates?

 

haha aaron, i had to read that a couple times

 

Nope.

 

The housings are important but the combination of your intake and exhaust with your particular port will make or break your engine. By that I mean a great port with the wrong intake and exhaust is just another sub average engine. Research is the key to avoid others mistakes.

 

A larger port gives better high rpm power but worse low rpm power. A smaller port is the reverse. A 6 port has 2 intake ports per rotor. 1 shuts off at low rpms, to get the best of both worlds. The other 2 ports are the exhaust ports, btw. In terms of peak power you can make just as much power or a little more with a large ported 4 port, but overall the 6 port is better.

 

^No, that's flat out wrong. A 4 port has 2 intake ports per rotor for a total of 4. A 6 port has one of those port enlarged and split into two, so that it makes 2 ports on the one side of the rotor and one on the other. At low rpms one of those ports closes so that you've got one port on each side. Looking at the side of the engine you can clearly see 6 distinct intake runners on the irons, two in the middle and 2 on each end.

 

Is there a way I could fill in the seal on the housings with the same stuff people use to fill the water jackets for bridgeporting?

 

Yes.
Usign devcon liquid steel after a thorough cleaning, you can fill the grooves in the second gen plates. Once set, mill the plates with a flycutter to remove the bulk of the excess epoxy, then have the plates lapped.