onepointone

ok.. well, sunday i got my motor, yesterday i tore it down, today i cleaned it up in the parts washer at my school except for the rotor housings and the rotors. i have a few questions though....

the car had 200k on it, and im pretty possitive it was the original engine, but it looked good inside minus the rotor housings had ALOT of flaking down before the exhaust port. i guess from alot of redlining? ill take pictures when i get ahold of a decent camera, but my question is, im definately going to need new housings, will any 13b housings fit? if not, which ones? or do i need to get housings off a gslse 13b? i see some people sellings good condition ones, but i dont remember the last time i saw gslse housings. i was thinking though, if i want to do this right, i should go get some new housings, but they are $400 a peice through mazdatrix. anyone know anywhere cheaper?

also, the 5th and 6th port valves where kinda stuck in there when we pulled the motor, but after the parts washer, one came out, and the other came out with a pair of pliers. the motor is going ot be carb'd, can i just leave them out? it seems that it would flow better without them, but i dont know if it will flow too much. im going to street port the motor, im just researchings that as well because i hear its a bitch and theres not much to work with, but i have side plates from my dad's 87 n/a im going to practice on. but if i do remove the valves, that means i can take the actuators off the lower intake manifold right? (lower intake manifold is needed for the carb im going with).

ALSO... i got the bar that goes across the front plate mounting it to the crossmember off the gslse, but i read on the mazdatrix site, you need the racing beat one since the crossmember is different? so theres no way to modify it to work?

any other things im forgetting?

sonic7

iTrader: (1)

if your street porting it, the 6th ports become useless, because streetporting will open the gap between the normal intake and the 6th ports intake. Im not sure whether or not you can leave the sleeves out or not though.

Justin

onepointone

anyone else?

ioTus

iTrader: (5)

street porting a gsl-se engine will give you about 190 guessed horsepower (quote from revolution rotary), w/o any other mods.

You can take the actuators off if you want, but if you have a 6 port engine w/ the 6th ports open all the time, there is no point. You could have more power from a 4 port engine street ported. So either leave them in, or go 4 port.

I am in the process of fixing my 6th ports. Until then they are wired open.

680RWHP12A

leave the 6 port sleeves out, what size carb are you going to use? make sure you matchport the intake manifold..

also get a 12a intermediate housing because you get the long port runners and you can do a fullsize streetport on it!= more hp!!!

onepointone

680, im actually going to buy that setup from you that we talked about in the e-mails. i was thinking with having the 6ports open, youd loose near all low end torque, but it seems that it would flow better, i dont see physically why it would. i would go 4 port, but im already in need of a carb, 2 new housings, a rebuild kit, header, and various other things, so i can only be but so picky.

can you explain a little more about the intermediate 12a housing? thast the center plate right? can i just go and pull that off any 12a at the junkyard. what about a rebuild kit? would i need to mix parts up with the kit? will it make the engine shorter, posing problems for the header/engine mounts? things of that nature.

680RWHP12A

that will directly swap with no problems! all the same gaskets, same motor dimensions, and yes you can get it from any 81-85 12a so it is easy to get. that hsg with a streetport and the 6 port outer housings makes for a powerful setup!. when you port a rotary, you loose low end so you need to build around that, light flywheel to get the powerband quicker, and rear end gear really help alot!

ps. you will have to trim the intake gasket for the larger intake port

onepointone

ill definately look into that. ive never seen in person the differences between the 12a and 13b center housing. i guess one day ill have to go to a junk yard and pull one apart for the center housing. is it just that theres more material there to port? also, do you have any information on porting 6ports? have you done it before, how bad was it/how much power increase. thanks for all your help man!

680RWHP12A

porting the 6 ports does increase hp, and the 12a center steel is bigger from the factory and has more meat for porting, that makes a difference too, along with manifold matchporting, a good carb, ignition, and exhaust it will make lots of power! sorry, i dont have any 6 port pics

onepointone

how hard would it be to match port the intake?

O 16581 72452 5

I've got my ports wired open, it helps alot with top end, but for cruising it's horrible... it struggles to get up hills when under 4k, i normally have to downshift or just keep the rpms at 4k when cruising.

knight1976

OK im pretty new to the first gen motors but in a gslse what actuates the 5th and 6th ports? Is it the exhaust or the airpump? Or is it something else entirely?

APT CSVT

There is an actuator for each additional port (5th and 6th) that open the ports. These are driven off air pressure from a tube that connects to the exahust. So, exhaust backpressure is what opens them which is supposed to be in the 3800rpm range. There is a separate tube in te exhaust for the air pump, but the air pump/smog system has nothing to do with the 5/6 ports.

knight1976

So does RB streetport exhaust have tubes to open up these ports? I didnt see any tubes like on the RB s4 presilencer. (i plan on running a RB streetport exhaust on my SE)

APT CSVT

Yes, both the street pot and stock port systems specifically for the 6 Pot GSL-SE have the actuator mount. Check out this description right from Racing Beat's web site:

Power Pulse Presilencer 1984-85 RX-7 GSL-SE*

The Power Pulse Presilencer is designed to be used with our wide selection of RX-7 Streetable Header/ Collectors to complete a bolt-on configuration. These Power Pulse Presilencers are ideal for those individuals wanting to fabricate custom exhaust systems incorporating either long or short primaries.

The Power Pulse Presilencer improves the character of the exhaust noise, dramatically reducing the inherent, obnoxious metallic high frequency noise with virtually no power loss. Constructed with a high temperature, 2-inch I.D. perforated core of 304 Stainless Steel wrapped with high-temperature stainless steel wool, the Power Pulse Presilencer measures 20 inches in length with a 4-inch outside diameter.

This presilencer is equipped with the six-port injection back-pressure pickup tube.

Gaskets are not included but are available separately.

* Legal in California for racing vehicles which may never be used upon a highway.

JLIU

I have the RB streetport exhaust setup in my 85se and my actuators do not open up at all. I think there is not enough back pressure to activate them. I have checked the actuators, the levers to the sleeves and the metal pipe that supplies air to the acutators and all are in perfect order. I know some of you have the same problem as me and some don't. Why??????

Jeff

ioTus

iTrader: (5)

Did they ever work?

i did a test on mine, i disconnected the backpressure tube, and blew into it (which SHOULD activate the aux. ports).

what happened? i heard air blowing out around each actuator.

HMMMM what does this mean? this means they are DEAD! and i need new ones. Where do i get new ones? parts cars and bone yards.

Good luck, i'll tell you if this fixes them.
~Geoff

JLIU

I don't know if the actuators ever work. This actuators thing was brought to my attention only after I install my RB streetport system. I think I will so the same thing you do by blowing into the rubber tube to see what happens. My other thought was if it is possible to adjust the screw on the bottom of the actuator so that it requires less pressure to activate them???

Jeff