I was looking into buying a cheap-o burnt out RX7 and rebuilding the engine for kicks using the rotoryaviation.com basic kit, but was wondering if porting a NA engine is going to be worth it. I did some reading on the mazdatrix site and they say that it sucks on a 6 port engine. NA=6 port and turbo=4 port, right?

 

Yes the N/A motors are 6 ports and the Turbo motors are 4 ports. Don't expect millions of HP when you port the motor but you will gain a nice amount (depending on your other modification and how you tune). Go to the no pistons web forum they have a section dedicated to rotary engine building. There you will see lots of different 6-port, port jobs. Everything from mild Street port to wild Judge Ito ports .

- Dana

 

Cool, I'll check that out, thanks.

Do you have any other porting resources? I'm interested in doing the job myself just so I've had the experience of building up a 13b and porting the puppy, but truthfully, I don't know a ton about ports aside that they enlarge the intake on the front/end/center sections, and have the effect of advancing what would be the equivilant of the intake valve timing on a piston engine.

*edited because I'm a retard.

 

I had my N/A engine stage one ported by Hayes Rotary,
installed a complete Racing Beat exhaust including presilencer and down pipe (no cats), K&N air filter, removed air pump and installed a blanking plate suggested by Racing Beat, removed most of the plastic under the Mazda metal sticker on the air filter box for more air flow.
This 87 didn't have ANY accessories, not even power steering....Sold it to a guy that said it was faster than his T-11, got 25-26 MPG too.
I'm going for a stage 2 street port on the next one....

 

How much did it cost to have them port it for you?

 

Yo be like me and go with TII housings, TII intermediate plate, S5 rotors, S5 e-shaft, S5 flywheel and counter weight, and do a half bridge. :-)

-B-

 

sounds like a nice little learning experience. i wanted to try something like that when i engine poops. mine's an S4 GXL and i have a full S5 engine at my disposal so DCRotor...how is it performance-wise...
i haven't really thought about it as much so i haven't done much research on it yet.

*...hmm..where to get TII engine parts*

 

Racing Beat has templates for porting, this is an option for you and a local machine shop. I had mine done at Hayes Rotary (check prices on the web site) as a package when they swapped my engine out.

 

I thought about having a shop do it, but I'd really like to do the whole build-up myself to say I did it.

I'm keeping an eye on eBay for people selling engines. If I can get one for cheap, I'll have a hell of a time ripping it apart just to see how everything works. It looks like shipping a shortblock is $300 though, ouch.

Do you only enlarge the center and bottom ports on the front and back? You really can't widen the aux. ports because the way the sleeve works, right?

 

e mail racing beat and get a catalog. They have a bunch of good writeups on this and this will clear up all your questions guaranteed.

 

I just poked around and ordered one right off their website. Thanks for the suggestion. I'm wondering how terrible it would be to do the turbo swap while the engine is out as well. I haven't done a whole lot of reading, but if I had a GTU, I would need a new exhaust manifold, the turbo, some oil lines, intake structures, and a new ECU, right? From the pictures I've seen it looks like past the downpipe the exhaust is basically the same, so that wouldn't be too bad and creating the necessary oil passages wouldn't be a pain if I'm already planning on ripping the engine apart.

That's just dreaming, but who knows? The time and money might fall into my hands in the future.

 

port just the secondaries for a half bridge and both exhausts. As for the TII housings or a short block go to the for sale section i'll be cheaper (the shipping for my short block was $175) remember you need alot more stuff to makeing this Monster N/A .. find some posts by BDC .. he does 1/2 bridges on turbos and is very knowlegdeable.

 

Hehe, I don't want to go completely nuts on it, but that sounds fun none-the-less.

 

A simple answer to your question?

Yes, porting ANY Rotary is a worth while upgrade....

It's nearly the same as installing a set of cams and porting the head on a pissed-on (boinger) engine.

-Markus

 

If I were to buy a kit, and have it done at local place, who would I go to, and roughly how much would it cost?

 

I ported my sparemotor using the rotary aviation seals and porting templates from a forum member.
I may say that its a worthwile mod, I also matchported the intake-manifolds and removed the entire emissions system and the 5/6th ports are still functional because eurospec. FC´s came with solenoid/diaphragm operated butterfly valves.
Check this thread for pics.
https://www.rx7club.com/showthread.p...hreadid=258319

Its easier than you think

Kim