Well I guess I should start a "build thread".
[This is a build for a 6 port 13B in my 79 RX7]

FOREWARNING: I am a motorbike engine guy (SOHC Fours in particular) I'm pretty unfamiliar with the rotor thing.

Here is the situation... I blew an apex seal in the front rotor. So the front rotor and housing is DONE. I'm in the market for a new (used) one; I've got some solid leads.




Next, 3mm or 2mm apex seals? I have (what I belive to be) a GSL-SE 13B engine. I am infering because its a 6 port engine, and I think thats a GSL-SE.

Back to the point. A GSL-SE engine uses 2mm apex seals... Right?? How do I messure them? Would it make a difference if I used a latter model 3mm rotor in front and the stock 2mm in the rear?




AND the 6 ports...

I've read a little about the auxilary ports. I know they open and close depending on the rpms of the car, but I am using an intake manifold that doesn't have an opening for the arms that turn the valves. Also, the stock exhaust is LONG since gone (probably two owners ago). I've heard at higher RPMs this is good due to the resonece of the openings, but at lower RPMs it drags the engine back.

Now my question, since I cannot return the intake to factory would it be good to seal up the auxilary ports? I could just stick the auxilary vavles in backwards.







Anyway, those are my questions. Can I block off my aux ports, and can I use a 3mm apex seal rotor in combination with a 2mm apex seal rotor?






ALRIGHT now for pics





My original setup. I know razz me about the Edelbrock; hey... it came with the car!







I just like this cause it shows the signifigant difference in size between the 12A and the 13B.







Like a true redneck I took it apart in the back of the pickup. haha






Everything cleaned up.... somewhat cleaned up ;-)

 

the engine on the back of the truck looks like an S5...

 

Mike, does the rear plate have a thick rib at the pedestal? I can't really tell on my monitor.

 

Please excuse my newbiness.

S5... Good or bad? What kinda seals should I be looking for?

Rib? Like a grove or something?

 

the engine has holes in the rotor housings for knock sensors, so its an 89-91 engine

 

Are you talking little pin holes in the rotor housings on the top?
I was staring at those with a buddy of mine we couldn't figure out what they were.

89-91... So that would mean 3mm seals? It definetly has 6 ports though.

I can't seem to locate my caliper in my shop... I've gotta track it down now!

 

Now I'm this far into this car I might as well go all the way. So the transmission is on the chop block!

New seals, gaskets, and some bearings. Why not!?

 

Looks like S5 turbo II housings. Exact housings i'm using in my turbo 13b.

The only way it could be a 6 port is if someone used N/A FC irons with those turbo housings. Or, had the rotor housings milled to have coolant grooves in them to work with pre 85' 6 port irons(gslse) like I did in my current engine.

S5 TII housings used rotors that had 2mm apex seals from the factory. You can use 3mm if the rotors are switched out, or modifications were done to the rotors to use 3mm. 2mm were original though.

 

So I should be on the the look out for some specific housings? Or the water jacket won't match up?

 

If the engine ran fine before then your good with the irons you have. You sure it's a 6 port engine? Post pics for us to confirm. Just saying that if it is 6 port it isn't original for those housings. Doesn't mean it can't work right though

 

Na, the Front rotor blew an apex seal... there are GIANT gouges and pieces missing out of the front housing.

What I would have giving to have X-ray vision when the seal went out!!!



Damn... Now ya'll got me curious as all get out. I'm going out to the garage now and taking some closeups of these parts. Stay tuned...

 

Firstly, little hole.... What is little hole... Why little hole... WHY?!?!
Meaning... 89 engine?




Now this is the irons...











So I put the irons up to the housings.... I own a MUTT... Mongrel... Half breed... Impure.
None of the coolent lines match up. I think a dremel tool is in my future

 

Think j9fd3s is right on the housings. I thought only the TII housings had spots for the knock sensors. Guess the N/A S5 housings do too.

Those aren't S5 turbo housings then. They didn't have baffles in the exhaust port. The little hole is for the factory omp(oil metering pump).

I wouldn't do any dremeling or anything till you do some more research on what you have. Looks like you got a S5 N/A engine. 6 port.

 

Yeah, I was told the baffels REALLY reduce the noise of the engine... I don't wanna remove them.

Yeah I guess the water can find its own way around. Its not like it doesn't match at all; it just has a lot of holes that go to nowhere.

 

http://www.ebay.com/itm/Mazda-Rx-7-R...db4824&vxp=mtr


So, from what I understand 13B housings are pretty much all similar except for diffusers, oiling systems, and the water jacket.

Couldn't I just get a random 13B housing and this pair of rotors and have a HAPPY engine?

 

I cleaned the beat up rotor and I guess it looks serviceable. I'm just gonna use it. As far as the shop manual is concerned it passes tolerences. It just has scrapes on the surface.









And I got a good condition housing from one of the local RX owners.




.

 

So I've decided to polish.... WHY?!?!?!! Bordom, and the OE anodizing was scard. Also, waiting for Atkins seals in the mail.






Before





After rubbing compond on the highspeed air drill. Not too shabby. Lets see what the Mag polish does






EDIT: what kinda clear coat are yall using on your Al bits?

 

yeah the important part are the seal grooves, the faces can be beat up a little and its ok.

 

My air drill died about half way into this!!! >

Oh well... gotta rebuild that tool now.

Still looks better at least some what.

 

Housings are done!





Cool... another use for a penny. Just gonna JB weld it in there.

EDIT: that's the intake coolent port BTW.







Questions..

What kinda break in is recomended for a fresh rotary build? Hard throttle or soft break in?

What kinda clear engine enamal is best for this kind of Al? I know what I like to use on my Honda bikes, but every Al cut is different and sometimes picky.




.

 

you shouldn't use those two rotor housings together, the one with the threaded hole above the spark plugs is S5 the other is S4 and if you look the spark plugs are actually in different locations.

 

Yeah you have 1 s5 and one s4 rotor housing. Dont mix them up use 2 of the same. And make sure you check the apex seal grooves on the rotor. Follow the fsm for the procedure.

 

Oh, good catch...

I guess I'll take the polished S5 to the guy I got the S4 from and see if he'll trade me for another S4 housing.





EDIT: still waiting for the seals in the mail anyway... just a bumer.

 

More cleaning and removal of old 12A's.




The RB intake cleaned up nicly though.




The bay looks a lot better in person. this is a REAL bad pic.

 

I feel as though a choir of angels should be singing in the background



This is the real deal BTW.