new to porting, rebuilding. some questions
 

Im new to this forum and fairly new to rotaries and working on cars in general, I'm using this post to introduce myself and my car as well as ask a few questions... when i was younger my parents owned an FB rx7 and now I'm a proud owner of my first N/A convertible s4 rx7. Im fairly new to working on cars in general but after my first 13b blew i got another motor, replaced nearly everything possible and swapped it in myself successfully only to find out that the engine that i found that tested so good out of the car revealed a blown water seal under high heat cycle probably from the engine sitting. oh well the 13b was free lol and learned a ton in the process of putting it in.

ANYWAYS I'm going to take the engine back out and have it rebuilt by a local guy in portland,OR thats been rebuilding rotaries since 1980 seems very knowledgeable and experienced. the engine still runs well so I'm hoping that the only thing damaged is an o ring and my rotor housings are still useable. Of course im getting a complete rebuild kit (atkins) but I would like to save some money by reusing the rotor housings if they are still good if not he has about 100 used ones in stock. I plan on having him do a tearport as well before he puts it back together that he said should get me up to about 220 hp.

my first question is, is it a good idea to rebuild the engine with used rotor housings?, how long can i expect them to last if they are in good condition now? vs Brand new housings? is it worth it to buy brand new ones? i know they are super spendy and is not really an option financially. is something else that i missed causing the water seal to pop?

also, if I am porting the engine (tearport like he said which i know very little about other than pictures) what kind of drivability changes can i expect? this car needs to be daily driven i want more hp because of the heavy convertible but not at the expense of drivability unless it's reasonable.
what effect will porting the engine this way have on engine life? used rotor housing life?

i would love to learn how to rebuild and port it myself but do not have the time for trial and error i need my car back, like i said Im fairly new to working on cars but am learning quickly Don't really have much experience with a piston engine and don't really care to:smokin:

I already have a few good upgrades on the car
Aftermarket downpipe
removed a cat and EGR
hi performance air filter
hi performance aluminum radiator
slotted rotors
new sound system with two tens in the already tiny trunk lol
NRG racing wheel and nardi personal shift knob
New convertible top

Re: new to porting, rebuilding. some questions
 

First of all, if it's an NA, then you would have a header, not a downpipe... one good practice is to know what are the specific parts on your car, so it's easier for us to help you. :)

In terms of porting, read here: Porting
I'm not sure what a teardrop porting is... have not heard of that term before, but to get a NA to 220HP, we are looking at either the more aggressive street port or bridgeport. Now, both will compromise on the engine life, but by how much would depend on your usage. For daily driving, personally I'd not suggest bridgeport due to noise and the harshness of drivability (this depends on each individual, I've heard different says about this).

As for rotor housing life, it's better to just use a new rotor housing; considering the extra stress the engine will be dealing with, it's better to have the peace of mind when you know the housings would not fail on you half way down the freeway. Also, if anything were to happen with the engine when it's put together with new parts, you have a more legitimate reason to bring it back to the shop and have them look after it.

Used housing are usable, but it's hard to determine how much life it will have until it is actually driven. Surely, with a lower mileage rotor housing we would naturally think it will last longer than higher mileage ones, but what was the housing used for we don't know - regular setup, race setup? There are many factors to consider to really know what the housing is able to handle afterwards. So this is more so your decision and consulting with your mechanic.

Epic service cheap won't be fast, and fast service cheap won't be epic. You do want an epic car right? So don't go the cheap route.

There are many things you can do to make the car lighter, you don't really need more horsepower to have a faster car, overall balance is more important. However, if you're really concerned about weight, here are some stuff you can do to reduce weight:
- Carbon fiber hood
- FRP front fenders
- Lightened Steel or Aluminum flywheel
- Lightened Steel or Aluminum driveshaft
- Aftermarket rims
- Aftermarket seats
- Smaller battery and/or battery relocation
- Fixed headlight conversion
- Performance brake kit (AWR Racing has a lighter and stronger version)

These are the easier doable stuff that can be done when you have the budget, but in the end you want to think about what you want the car for. Like I mentioned, overall balance is more important.

Hopefully these information helps you to decide on what you will be doing with the car and the engine.

Re: new to porting, rebuilding. some questions
 

i am a complete newb with cars in general, but i can learn things, just stripped the entire engine down and am ready to take the keg out all last night in 4 hours pretty proud of myself have never done anything like this in my life i watched my friend do the last one and i helped a bit but being on my own was different, but I've found this rotary engine stuff to be fairly easy because of how small it is and simple. didnt use the book not that its any help really. found quite a few vac lines that need to be replaced still from the last swap. i guess it would have to be turbo to be a downpipe idk like i said i am fairly newb status my friend is making me a custom exhaust straight piping with two cats it sounds EPIC. i guess what i would be doing port wise is a small to medium street port, this car is very fast for me already dont really need much over 185hp if at all just looking to beef it up slightly since im taking the engine out anyway and since its the heaviest model the convertible, he has several used rotor housings and im fairly sure mine are good (find out tomorrow) cant really afford to go with new housings right now. i literally like just started working on this car and its pretty much my first foray into mechanics ever lol so i think things are going pretty well considering. i guess my questions have been pretty much answered, too many factors to really tell exactly how much life is left in what but cant afford to go with new housings so i guess my mind is made up. as far as the internals will i need a full kit or can i just replace what needs to be replaced? or is that a bad idea? i want this car to last, but now that i can swap it myself wouldnt be horrible to replace the engine again down the line. debating on the port smmaller port or medium. this car is a daily driver i dont wanna do anything too crazy

Re: new to porting, rebuilding. some questions
 

found new rotor housings on mazdatrix for 600 is that the cheapest they run?

Re: new to porting, rebuilding. some questions
 

i would love to rebuild this engine myself, if i got the atkins dvd how likely is it that i could do this right the first time what type of things can u screw up as a rookie or is the dvd really good, as far as i can see rebuilding a rotary seems like something i can do not too complex and no special tools needed reallly. if i could save money on the rebuild labor i can put it into other upgrades for the car like suspension

Re: new to porting, rebuilding. some questions
 

I believe it's cheaper if you get everything as a package kit... regardless of the price, it's always nice to just get everything, in case you actually need the parts you originally thought you didn't.

If you can do it, have the facility and tools to do so, and don't mind learning along the way, then it's best to do it yourself. Nothing is more fun than driving a car that you have worked hard putting it together. And yes, the amount of money you saved can go somewhere else.

However, with porting, it's best to have an experienced mechanic who have done it to do the grinding for you. The rotor housing cannot be used if you screw up. Also, make sure the rotors get balanced to ensure longer life-span.

Re: new to porting, rebuilding. some questions
 

thanks for the info, appreciate it. My friend and I are both going to try to rebuild our 13bs for the first time, mine going back in the rx7 his going in a nissan s12. Going to buy the rebuild dvd from Mazdatrix and get the pieces i need from pineapple racing. Im going to get it streetported by the rotary guy i talked to about rebuilding, then put it together myself. although he offered me templates and i happen to have two chattered up rotor housings to practice on and at worst if i screw up on the real deal can buy good conditioned used ones from this guy. maybe I'll learn the whole shhbang might as well, you are right I love the idea of building and installing an engine all myself and knowing that if anything is screwed up it's my own doing. Learning this stuff out of necessity right now but i have always been interested in rotaries and how to put them together and their modular nature ever since i first saaw the design. I'm a sucker for unique intelligent inventions that don't get enough credit. haven't searched the forums yet but does anyone know of a site that gives some guidance on porting?

Re: new to porting, rebuilding. some questions
 

this site is a good one for porting info. lynn hanover is the fella with experience and keen to share hunt him down and email him, he should put some videos on youtube :)

Re: new to porting, rebuilding. some questions
 

well i decided to pay this guy to do the rebuild hes got a lot of great used performance parts hes selling to me. sort of a dilemma because i have no experience and i want learn it all myself but i also dont want to screw up another keg, so we are going to do it all together hes going to hand me the rotors and i put them in kinda thing, hes totally transparent hell show you anything you want to know, im almost more excited just learning how to do it all then i am about how good the car is going to run. the rotors have been assembled and cleaned, we start putting the rest together tomorrow. pay him once its a lot sure, but really its mostly the cost of the parts his labor charge is minimal and ill be able to do it all myself the next time and have a little more assurance that its right this time. So i feel good about my decision and my vision for this car I dont have a ton of money right now but i made a list of planned modifications for my car, Im going to just sort of slowly check off the list as i have the finances, some of the things i have decided on a certain brand or manufacturer others im leaving to flexibility.

everything in black i need to get or have done, everything in red or blue i already have, or is already installed, or done.

Im not completely new but basically as you computer forum people say a newb....
opinions, thoughts? on parts? other ideas, priorities? my friend is going to do a custom header and cat back for me once the engine is in, my vision for this car is just a decently fast n/a around 210 hp with really solid suspension and lots of comfort as its still a convertible and ill wanna keep cruise control and ac for my long ass drives and i like comfy and i like girls and girls like comfy... u get the idea...

Re: new to porting, rebuilding. some questions
 

btw here is the CXracing radiator i ordered originally, here is the fitment or LACK THERE OF showing the lower hose, I was told it would be DIRECT FIT BOLT ON.

i talked to them for two emails he said he doesnt get what the problem is, i show him the fitment in this picture and he hasnt responded since. i want silicon hoses and would prefer not searching through hundreds of hoses at carquest for the right shape ever again.

Re: new to porting, rebuilding. some questions
 

Sorry to hear about the radiator issue dude...


I don't quite get what you meant there with the color code, but I'll assume the red & blue are already done or parts waiting to install.

Here are my recommendations in order of priority:
- SS clutch line. Replace the Master and slave clutch cylinder if it's never been done.
- SS brake lines. There is also a Brake cylinder brace that you could consider getting. Look here: Level Zero Motorsports
- Bushings. Energy Suspension sells a master bushing kit and also individually, get every bushing except the sway bar ones, cause the Racing Beat sway bars come with their own bushings.
- Sway bar links. Order 2 of the same one from Racing Beat.
- DTSS eliminator kit. Available through Racing Beat, Mazdatrix, or Level Zero Motorports.
- Front strut bar.
- Rear camber adjuster link. Available through AWR Racing, Racing Beat, Mazdatrix, Corksport, or Banzai Racing.
- Coilover.
- Silicone radiator hoses.
- Electric fan. Make sure it's above 2300 cfm, comes with a shroud, and is big enough to cover the entire radiator.
- Radiator panel. Corksport's is made of FRP, a lot of people commented it's bad quality. S2Carbonworks sells a metal one for about the same price: 86-92 Mazda RX7 SIGNAL Auto Radiator Cooling Panel FC3S
- Oil catch can. Not needed for NA, this is for turbo engines.
- Hi-flow cat. Look here for the Bonez cat, best one out there: Rotary Performance | FC Exhaust

Exterior, interior, and the future plan list are more of personal preference, so do them when you have the spare money.

Re: new to porting, rebuilding. some questions
 

First off I highly appreciate the response exactly what i was looking for thanks for the insight.

the red stuff i already have or installed the blue stuff im paying my rebuilder to provide after the rebuild as part of the cost so i could keep track of what i owe him money for and so he can remember what to grab for me.

-The radiator was a headache, but my rebuilder is trading me another one that fits better for my old one and a few extra dollars

-yea i noticed most bushing kits come with the sway bar bushings which i wouldn't need because im getting new sway bars that come with them thats why i listed just the control arms.

-oh yea and im getting my injectors rebuilt

-don't know if i have ever driven a four puck clutch he has a three puck clutch one too i think both dont have springs, whats this gonna feel like driving?

-after blowing the first motor from overheating im super all about the cooling system so those silicon hoses are gonna be in there asap as well as the electric fan, radiator panel and hood vent, i noticed from the manual some rx7s had optional electric fans as well as the clutch fan the electric being a small fan located on the opposite side. could i do that do both or would that rob some power, better off one or the other? electric for sure?

-i think as far as my priorities go im gonna take care of the engine as much as possible first, then the brake and clutch lines and cylinders, then the bushings, then some of the more expensive suspension stuff, i think i need a new wheel bearing on my front passenger wheel. its definitely helpful to figure out the cost of everything and prioritize it based on whats important to you and the vision of the car seems like. unless your rich i guess

-oh ya and i forgot the msd ignition

already have a hi-flow cat the bonez might be better not even sure what i got i can just tell its very new and not the normal cat

again thanks for the advice very helpful

Re: new to porting, rebuilding. some questions
 

the radiator panel is pretty silly to pay for i could get a piece of sheet metal and make one in like an hour.

also instead of buying the atkins sleeves or pineapple inserts why couldnt you just put some epoxy in the six port sleeves and then grind them the right flow shape, would the epoxy come loose and fall into the engine? im thinking it would be fine

Re: new to porting, rebuilding. some questions
 

It is not unusual to find that direct replacement just means you can probably get the hood to close over it.
Welcome aboard. You can buy a few cheap hoses of the corrct diameter and cut and fit to your application. Where you need a twist in the hose or a straight run, just cut it in two and fit a short length of the correct diameter exhaust pipe tubing.
Then you can use your prototype hose as is or, take the prototype to a dealer in blue silicone to buy the pieces you need. For longer straight lengths use aluminum tubing polished up like chrome.

Most junk yards have a core pile, where damaged engines are kept until they have a load, or the price of scrap goes up. I got my first rotary in such a yard for free. It kept rolling off of the pile and blocking a lane. From two or three core engines you can come up with a complete runner.

Most people just port the end irons, or secondary ports.
A street port is plenty for starters. The primary ports are the little ones in the center iron. Left stock this gives you nearly stock performance and some nearly stock mileage.
Plus it remains so docile that you mother can drive it and not notice a thing.

For the street port, paint up the irons with a Magic marker and scribe the path of both ends of a side seal over the port area. Move the open line to about 1/8" of the scribe line. Here you want to have both ends of the seal supported as it passes over the port. The closing line over the top is moved up to extend port open time. Stock is about 55 or 60 drgrees. Wild ass racing up to 9,500 RPM can be up to 85 dgrees. Less is more the first time around. Radius and polish the closing line to look like chrome. No wear at all on the seals. They will go almost to stock replacement time. Less the hours when you have both feet on the loud pedal. In an off the road situation with medical help standing by of course.

Do not enlarge runners. You want the highest possible runner velocity at all times. Read Bernulli.

The bowl below the port face is already too large, so just smooth and polish the outer surface to a chrome finish. Smooth the inner radius but do not polish. Install a heated O2 sensor and tune to keep full throttle show off RPM in the mid 12s.

Lynn E. Hanover

Re: new to porting, rebuilding. some questions
 

thanks for the reply and very concise tips on porting,

yes I'm quickly learning what the term bolt on actually means, bolt on-ish. I already got a different radiator that fits better and will be stopping by corksport for some red silicon hoses today. Even if i could make that radiator work it gives me a bad vibe lol, i want it gone.

The engine I am rebuilding was on craigslist for $50, I drove down and he just gave it to me. even though i went through the hassle of testing(tested great) and installing it, only to find out the front water seal was bad as well as the center housing and both rotor housings, it was free and i got some experience removing and installing the engine so, oh well. which goes to show you really have to crack the keg open to have any clue whats going on in there, obviously.

Im modeling the intake (housing plate) port basically after the TII port, Im not messing with the runners, the exhaust porting is going bigger but just upward not lower than the bottom already is, sleeves removed.


I was gonna order the atkins sleeves online but noticed the atkins looked slightly different from the mazda factory sleeves, so I went over to pineapple racing and picked up his six port sleeve inserts. I recommend them over the atkins sleeves because the thing i noticed was the factory sleeves have been turned on a lathe once more near the rod part, seems like to allow for some buildup and still be able to turn well. the atkins sleeves do not have this portion. Also the pineapple inserts are only 39 dollars and come with new pins. For those of you worried if the sleeves are going to fall out and break your keg, it ain't happening. First of all as you can see in the pic ( look how shiny i cleaned them! ) there are two points where you take a peen hammer and screwdriver and make indents just in front of the insert to keep the insert from ever moving in the unlikely event that the 'loc tite' doesn't, well.... lock tightly. Also even if you didn't peen it i highly doubt that little piece of aluminum is going to come crashing through and break the pin lol, not going to happen.

after talking with rob a little bit i decided on a game plan for the suspension. Here is an updated modifications list, im going for a street/drift/stock/sleeper build that is practical for daily driving(female friendly) but can still have some serious fun at the track or on the street, stock springs maybe change to something else when i get the funds but im def getting a better front sway bar and removing the rear one as well as a front strut tower bar and getting rid of the dtss. I will adjust/upgrade the suspension as my driving experience, style and cash flow dictates.

my next step would be to start reducing weight, I will have to get creative. Any ideas on weight reduction on my vert beyond what i already have?

Re: new to porting, rebuilding. some questions
 

Weight reduction wise can go anywhere, but since you want to keep the car relative friendly for daily driving, then you should keep most of the interior stuff together.

Couple things that you can do are:
1. Front fenders - OEM are steel ones, so change to FRP units
2. Hood - Unless you have aluminum one on, otherwise change to either FRP or CF ones
3. OEM headlight - Can change to fixed headlights to reduce some weight from the assembly and the motor
4. Single exit exhaust - weight wise is not that much less compared to dual exit, but still something to think about
5. Driveshaft - Lighten steel or aluminum units, can get them from Mazdatrix
6. Brake rotors - AWR racing offers a brake upgrade kit that reduces rotating weight by 10lbs
7. Rims - Aftermarket ones are usually lighter, but check the specs before going with specific ones
8. Seats - You're already changing the driver's side, but the passenger side could be changed too. Vert seats are heavier due to the headrest speakers.

That's pretty much all I can think of now, hopefully these help you get some directions.

Re: new to porting, rebuilding. some questions
 

i have def decided to knock as much weight off as possible my plan is single exhaust, Lightweight racing FIA bucket seats will knock a good amount off seeing as i have the headrest speaker seats, fixed headlight conversion looks sexy as hell( custom fab keeping oem bumper unless i walk into a money tree and get the shine auto or re amemiya one) Braille lightweight battery, getting rid of one of my subs, ditching ac, cruise, and air pump( once i get RB header) im in love with the stock bbs wheels as they are in perfect shape, and again if i walk into a money tree ill def get lightweight ones, frp fenders would be great i cant seem to find frp fenders that are not wide body, i am going for a stock-ish look with focus on weight reduction. but anyways

I was wondering if someone maybe lynn had a picture of a nice
exhaust port (view from the outside not inside the housing)