tesla042

Ok.. I just got a 245$ '87 se.. I already have a daily driver, so I'm planning on just making this car crazy and fun. I've heard both that I *CAN* and *CAN NOT* effectively port the n/a housings. I'm going back and forth between the largest street port i can do, and a moderate bridge port. Longevity isn't the biggest concern, but it's nice..

Do I need t2 housings to do a bridge port? A street port? What's the most I could squeeze out of the n/a housings? I assume I need a new manifold (lower, at least), if i use the t2 housings...right?

Thanks,
-Tesla

SpeedRacer

Well the 6-ports make it hard to do anything more than a mild street-port, since make the regular port any much larger would make it merge with the 5-6th ports. Also the exhaust ports can't be ported because of some weird "thingy" in it. To learn more about the weird "thingy", check out http://www.mazdatrix.com/faq/6pexh.htm
And heres more info about porting 6-ports. http://www.mazdatrix.com/faq/port6p.htm

tesla042

Well damn.. So I need off a t2 (or gsl-se) block: two rotor housings, center piece, and two end pieces? Bleh

On that link, it says:
<B>If the separate ports (in the end housings) are simply made into one large port, the bottom and mid-range torque suffer a lot, and the port velocity is compromised as the intake flows from the manifold into the intake runner.</B>.. But they're assuming i'd keep the 6p sleeves in.. Those would go. Does that make a difference?

Looking at the pics, it *APPEARS* that I could completely combine the ports all the way.. not just on the combustion face, but on the external side of the block...all the way thru. Granted, I don't have a housing here to see if that's feasable or not.. How does that sound?

Anyway, for all that, I may as well just do a turbo swap.. It sounds like it will practically be a turbo engine (w/ higher compression rotors, and no turbo..) after i'm done..

-Tesla

peejay

No, you DON'T want to enlarge the port runners (the part inside the housing) so that they are all one runner! I've seen it done, but it would totally kill off the velocity in the ports and you'd make no torque anywhere.

Race exhaust ports (IE for bridge or peripheral porting) eliminate the exhaust sleeve anyway, the port is that big. I don't know about how long the engines last with no sleeve in there to protect the aluminum, it seems to be a race-only mod.

fuzzi

as for the comment above about porting out the exhuast ports.. thats bull... I ported out mine... and it works great .... you dont need to get a turbo housing just a crazy tool ! and an air compresser... just buzz either side of that little silencer thing then pop it out with a screw driver, and grind down the remaining bit again with the grinder tool... You may have to buy and extra bit for your tool because it may where it out (its really hard)... but it can be done !! As far as a street port is concerned you can get real good power out of a street port....If it is a real good port you can get as much hp as a stock turbo....

tesla042

Cool.. So did you port the exhaust any wider besides removing that metal thingy?

Do you mean, a street port on the n/a housings? That's what I would really like to do.. I'd be quite happy with ~180-200hp at the wheels, as I plan on doing some crazy weight reduction on this sucker..

-Tesla

Dak

You can't use GSL-SE housings because the water O-rings were in the rotor housings on all pre-86 cars.All cars after '86 had the O-rings in the end and intermediate housing.As for porting the exhaust you can use TII rotor housings they don't have the splitter sleeves,you just have to block off the a couple of water passages that the n/a intake doesn't use.As for the 6-port side housings a friend of mine told me you can end up with a port with more volume than a turbo port because of the port timing.The 6-port port closes later than you could ever port a turbo housing to close.At least thats what he told me,I don't know for a fact.so a large street port should work but you will lose low end,all your power will be made on top.I don't see why you couldn't bridge port the n/a housings but there could be a reason I don't know about.Oh also you might want to use a TII intermediate housing 'cause the stock port is bigger and I think I heard that you can port it larger than a n/a housing.

SpeedRacer

I talked to a VERY experienced Rotary guy yesterday who has ported TONS of Rotary engines 12A's and 13B's that have been used for street and racing. He told me he has done many 6-port engine ports where he made the 5-th and 6-ports merge with the main port on the end housings to make a giant port. He admits it hurts your low-end pretty bad, but he explained it to me like this. "These cars will never have a great low-end, so you might as well make'em so they have a badass top-end" Anyways, he said the top-end that will result from making one giant port is well worth the loss of low-end...Of course thats just one opinion. And he said it won't really effect the life of the engine. This guy is currently working on a race team in Portland that races Rotary cars, so I believe him.

pp13bnos

iTrader: (1)

I had Rob at Pineapple build me a street ported 13B 6 port engine that had the 6 ports combined. It made right around 220 hp, had a 1,200rpm semi lumpy idle and started making realy good power about 4.5k to 9,2k. At 9k it was on the down side of the power band, but it had only dropped about 5-10hp according to the dyno graph. The bottom end was'nt even that bad. I think the key to making it run off the bottom end is the exaust. I ran dual 2" manderal bent exaust all the way out. So there was no collecter at all. I actually have pics of the porting, but I promised Rob that i would'nt post them on the internet.

CJ

peejay

too late CJ, saw 'em on the RX-7 FB mailing list

along with the crazy-large monster bridges that they do.... yeesh!

i bet those make good power from 9.5 to 11.5k

fuzzi

Yah i dont know if it is the best idea for street use to put together the two ports... my buddy did that.. like u said its got a rough idle at like 2500 rpm... and your real power doesnt even start until about 7-8ooo rpm... engines dont last very long with that type of porting

tesla042

This wouldn't really be a street application so much.. If i could do something like what pp13bnos had, that sounds pretty good... btw, pp13bnos, check your pm's..

Did your buddy combine them just on the combustion face, or all the way back to the manifold face? What did he do about the manifold, and the 6p setup? Combine the tubes IN it?

What all do i need to be able to safely spin up to 9-10k rpm? Hardened gears? Have it balanced by a rotary shop?

-Tesla

Dak

Hardened gears,the rotating assembly balanced,race clearancing of the rotors and bearings,retained rotor gears.There may be more but I think that is it.
Oh and a different ECU.The stock ones fuel cut is at 8500rpm on an '89-92 car(may be lower on '86-88)so the stock computer won't let it rev that high.

Felix Wankel

The exhaust port sleeves are held in with pins. Is it possible to find some junk TII rotor housings and just swap the sleeves out? That would save some money...

fuzzi

If your gonna do all that.. then i strongly suggest getting some stronger apex seals while your at it... for durability.

tesla042

What is everyone's opinion on the Hurley apex seals? Think they would be okay for this application?

http://www.hurley-engineering.ltd.uk..._Tip_Seals.htm for the racing ones, http://www.hurley-engineering.ltd.uk..._Tip_Seals.htm for the "normal" ones.. does anyone know if a hurley "set" is 3 or 6?

-Tesla