t-von

iTrader: (8)

Mods to the car:

Here is the thread about the damage.

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/didnt-think-id-ever-post-she-blew-464716/

Maxthe7man

There are alot of chatter marks on that housing, notice how the wear patter is inconsistant across the width of the housing... Those look oretty much how mine looked...The seals pressure wasnt consistant...

cmartinp28

i've talked to a couple of experts that have used these seals, namely Dragon, and steve kan....

dragon has used them on many of the high powered cars that he builds in okinawa japan, and did say that they wear housings fairly quickly, but the seals do not break... ever.... also, he did say that they work best with new housings, and a fairly good amount of premix, 100:1. most of the guys in okinawa actually uses them, and jspec7racer actually pinched the rotor seats from detonation before breaking the seals, this gives the impression that the seals are harder than the material used for the rotors (cant be good).

steve kan said that these seals will not break, but high temperatures will cause the center to bend, therefore causeing it to lose compression. he did not comment on its effects on the wear on the housings, just the possible loss of power as milage adds up.

in anycase, i have 8000 miles on my car, made 350hp to the wheels at 11psi just 50 miles ago, premixing 1oz:1gal (1:128)
i have anelectronic compression tester ready to be assembled, ill gather as much info i can get from my engine. whenever i need to build my engine again, these seals will not be used.... there are too many question marks about them, whereas stock seals would be sufficient.

t-von

iTrader: (8)

Well I've finally torn my 91 NA engine down and am in the process of gathering things for the rebuild. I bought the car with 75k and it already had 10k on a mazda reman. The car now has 140k so the engine only has 75k on it. Sadly my driving habits is what killed the engine. Since 1999 (when I bought it) I've driven the car way to conservatively. My driving habits consisted of 3k rpm shifts. This engine hardly ever was run hard and it showed with the excessive carbon buildup inside. Both aux ports were stuck(one open and one closed filled with carbon flakes). I let my sister borrow the car for a short time and I noticed that she drove the car differently than I did. She revved it a lot higher than me. It lasted a month in her possession. Apparently her consistent higher revving allowed some carbon flakes to dislodged from the stuck open rear aux port and took out a rear apex seal. All the other seals were fine because they were frozen in their grooves. I fine this funny because I took really good care of the care maintenance wise and it still blew because I didn't drive it hard enough or perform any carbon cleanings. Anyways that's what happened to my engine.


As menchiond above, I'm currently in the process of gathering items for the rebuild. I just received my RA seals today and noticed something very interesting.

1st off these seals don't have any numbers or stamps of any kind anywhere.

2nd of all there was a slight machining error of the small seal grooves. I lined the seals up and noticed it. I don't think it will be a problem to use them because 3 of them match so I will just keep the matching set together for each rotor. The machining is slightly off center but the grooves are exactly the same width as you will see in the pic.

Lastly remember when I asked if the seals face had a rough texture(see above quote)? Well I checked all of these and they do have small lines that extend the length of the seal face from the machining process. I have 20/20 vision and can clearly see and feel it with my finger nails. I can't take a pic of it because my camera wont focus that close. If you've ever seen one of those concrete nails, that would give you an idea of what it looks like(but on a much smaller scale). As hard as these seals are, I can easily see how these small lines could cause some of the housing wear until the seals worn in and smoothed out. These lines could also contribute to the wear in the rotor grooves because the slightly rough face isn't going to smoothly travel across the rotor housing causing added resistance until they wear in. I really don't know just speculating but it sounds plausible.

So with that in mind I'm going to polish 3 of the the seal faces and install them in my front rotor housing and install the rear ones in their raw state. After 10k I'm going to break the engine down and see it there are any differences front and rear.

moehler

iTrader: (12)

Great! Keep us updated. How are you going to polish down the seals? Be careful not to grind them so they are no longer in spec.

t-von

iTrader: (8)

I think some 400 grit wet sandpaper (with very light pressure)on a vibrating sander should do the trick. I'll just use some pliers to hold them and sand along the radius of the seals face(back and forward).

moehler

iTrader: (12)

IMHO, sandpaper is going to do the same thing as an engine at thousands of RPM's. I don't think that this seal roughness lasts very long or causes any initial damage. Either way, I'm glad you are willing to test it out.

GUITARJUNKIE28

you might have a little better luck by getting a machined flat piece of steel and gluing the sandpaper to that, then go lengthwise for consistancy.

t-von

iTrader: (8)

Too late already did it. I have a 1/2" sheet of aluminum that I used as my flat edge with the sand paper. It didn't take long either. I also had to modify the small seal groove slightly. I was doing a dry fit of the engine and was trying to install the seals with springs but the small spring kept sliding down to the bottom towards the larger seal spring. I was installing the springs the way that Bruce Turrentine does in the RA rebuild video. After a close inspection it appeared that the small lip that holds the small spring in it's place had a rounded bottom edge. This allowed the small spring to glide over the small ridge during installation. So out came the dremel and a small round grinding stone. I used it to slightly deepen and square the groove. Now the small spring stays in place(like it's supposed to when pushed in). This also makes me wonder how many other people that have these seals have the small springs installed properly. This may be one of the contributing factors to some of the warped seals because of improper spring pressure. See pics.

t-von

iTrader: (8)

That may be true but remember how much harder these seals are compared to the others. Another thing to think about is the condition of your intake manifold after the rebuild. How many people here actually clean their intake manifolds? I've noticed a **** load of carbon flakes in the in my LIM (with aux ports). The carbon build-up inside will easily break away from the side walls and be sucked into the intake during engine operation. These flakes will get caught in between the apex seals and housing causing scratches.

yodaddy

More good news for those of you who have these or are fans of them. I finally got around to yanking my engine and tearing it down. I was worried that I had broken these seals and warped some of them as well. I blew up my engine a little while ago and feared the worst, that I had also destroyed my housings like some people have claimed these seals did. The seals are perfect, no warping or breaks. The housings are also perfect, look just like the day I put them in. I blew 3 side seals and 3 corner seals. One of each in the rear rotor, and two of each in the front. I didn't have a chance to get pics but I will post some up after Christmas. This motor had approx. 10,000 miles on it when it let go, and I suspect sticky injectors are to blame. I'll keep you guys updated when I get a chance to measure stuff and get pics. My only other worry is that I may have worn the seal grooves out but I will check in the next week. Happy Holidays.

dubulup

over 11,500 miles and up to 19psi of boost...and the engine seems to want more

Judge Ito

I read these seals are made by a company called.. Real World Solutions, and sold by rotary aviation.. I am currently using them on my race engine. nothing but good results....Only thing I did different was use factory mazda oem apex seals springs, instead of the one they supply with the apex seals.

EFINI_RX-7_RZ

Real World Solutions = www.rotaryaviation.com

t-von

iTrader: (8)

Is this the same engine with the full bridge/Semi PP? If it is, how did you keep the corner piece of the apex seal from falling in the bridge port? Also you did the right thing by using the stock springs. The RA ones really are junk. I tried arching one of them (like you can re-arch the stock ones)and it bent almost to a V shape. This is because the RA springs aren't heat treated like the stock ones.

yodaddy

I didn't have a chance to get the pics yet but there is some damage noticed on the housings since i got them all cleaned up. There wear is a little more than they were going in but nothing to worry about, when the motor tried to spit out the broken seals it gouged the housings around the exhaust ports, which suprisingly didn't damage the apex seals at all. The weird thing I did notice is that the seals had some crabon build up on them, after scrubbing it off I found that it was building up in some pitts that had developed on the seals, kinda like rust pitts. It almost looks like there is a finish coating that has come off, but more likely just pits that developed somehow, I don't know what could have caused these, any ideas? I'll try to get some pics asap.

t-von

iTrader: (8)

You know I had a slight problem with my rebuild and had to open it back up after 30 mins of it running. I noticed the same carbon build-up on my RA seals. But after only 30 min of engine operation. I haven't gotten around to cleaning the seals yet. I'll also do a close inspection and look for pit marks.


Above is my old post. Since my engine is apart again, I did notice that the 3 seals that I didn't sand the seals faces smooth had already smoothed out some. But some of the machining marks are still present. I'll get the engine back together this weekend.

banzaitoyota

and they are lapped by the lapping shop that does irons for me

t-von

iTrader: (8)

Got the engine back together and running. I re-used my housings and even the one that was slightly damaged from the broken apex seal. So far so good. The car started up the first time and I didn't even have to put in any oil or tranny fluid to build start-up compression. It's break-in time . During the rebuild I removed the sleeves and had a shop cut out the diffusers. I still have the stock manifold and exhaust but now you can really hear the exhaust pulses with the sleeves gone. It sounds like pop corn and is much louder now. It's sure to be really loud when I design my exhaust set-up.

RotaryResurrection

iTrader: (8)

UH...if you reused the same seals and housings, and didnt rearrange the seals to different housings, then you dont need a breakin. Unless they were not broken in from the last time, that is.

t-von

iTrader: (8)

I'm running new RA seals. Plus I had to swap rotors because of the previous rotors were damaged(one due to broken apex seal and the other due to my own ignorance). So this means that the side and corners seals were rearranged on the different rotors. All but 2 side seals clearanced properly in the other rotors so I had to buy two more. Overall the engine has new RA apex seals and 2 new side seals with original springs ect. Oh yea it even has used viton oil control rings and new teflon encapsulated coolant seals. Kevin if you were following this thread, this engine is an experiment on the RA seals and will be broken back down at 10k for inspection purposes. I'm doing some other little experiments within the engine.

The only problems I'm having is there is now a strange noise coming from were the 5th and 6th port actuators are. It sounds like a squeaking belt. There is no noise when the engine is warming up, but when fully warm, the noise appears. Lately it's been an off and on thing. Also I installed new OMP lines and it is taking forever for the lines to fill with oil. I see air bubbles in them. Good thing I have premix in the tank. This is off my S5 NA vert.

drago86

I'd just like to add that my motor with ~10k, NA, limited to 8k rpm, street drive, stock omp, no overheating or detonation, Now has junk housings that look just like the housing on the first page of this thread. The housings were perfect 60k housings when they went in, and now they are deeply scored junk.

RA seals cause extreme adheasive wear, end of discussion.


I also believe my RA springs to be out of spec ( havn't measured yet, just compared to used stock springs)


Dont let these things get anywhere near your motor unless your housings are allready junk.

rotariesrule

t-von,

you suppose to pre-fill the omp lines with a syringe of oil.

t-von

iTrader: (8)

Damn didn't know that. Thx for the tip.

twister7

iTrader: (3)

I think I know why or at lest have an idea why these fail and maybe a way to make them last, any one ever see a bearing starved for oil, what it looks like in the early stages before it spins and starts lifting material? Sotra reminds me of the pics of the housing u guys are posting up (to a less extent ) also the ra’s bend in the center and the springs fail =to much heat or not enough lub (hard surface+hard surface =heat). In my option this is caused buy one of 2 things or maybe both 1) to much pressure on the housing from the seal, I would like to know how RA’s compare to oem (mic it) or what clearance are u guys running (tighter seal +less gas pressure escapes= more pressure on seal=more pressure on the housing)(more than likely NOT)!More likely 2) the lack of oil flim on the surface,,from what I can tell and from what I read there has always been a problem with keep oil on the housing surface were the apex seal rides “KenichiYamamoto” book goes into to this some pg 60 4.5 there has also been some ase paper talking about this some “860560 material technology development applied to rotary engine at mazda feb 24-28 1986” the idea iam getting from all this, is the oem seals work and fail because they are like a honey come hard metal with soft metal inbetween witch acts or is self lubricating, the hard metal (cast what ever) give the seal the strength the soft( metal-impregnated what ever) gives it a self lubrication/anti seizing like feature, wile oem is long lasting in a oem engine I can see y its not so strong, honey come cast impregnated like(basically hard and soft) vs straight cast or steal (all hard meteral one piece forged)!Ever wonder y the rotary can be premixed 100-1 to 200-1 and work, when most 2-cycle engines call for some were around 32-1(yes I understand it lubs more than just the rings) hummm, so what u have is either a weaker seal witch is some what self lubricating (oem) or a stronger seal witch is not or not as much or not at all self lubricating ra’s, and will tend to seizing or score the housing surface because of lack of lubrication, cant have the best of both worlds, to hard surface together with contack will be hard to get them both to live together w/o seizing & score one will have to give! I would love to see what would happen if say one rotor was premixed at like 32-1 or some thing below 50-1 and the other was premixed normal 100-1 or how long they will last with the below 50-1 premix (lol let the smoke begin)!Another option would be direct lub of the apex seal http://www.hurleyrotary.com/hmelub.aspx wonder y they are doing this humm (personal option this should have been done in the first place by mazda)! fyi racing beat even states (in there catalog )some high oil to fuel ratios for high powered engine’s 24-1, 32-1 or some thing like that! Fyi t-von if I were u I would premix the hell out of it(I would love to see thses seals live), lol only problem then would be increased carbon deposits and the nice smell of smoke (2 cycle oil or not) complication, complication, complication don’t u just love the aftermarket, time for a light water injection system to keep the carbon down more money more money!!
Any ways good luck

PS ANY ONE KNOW WERE I CAN GET MY HANDS ON MORE SAE PAPER’S?