Just read the thread with good discussion on the RA seals, and would like to see something similar about the above seals.

In case everyone is not aware, numerous engine builders are having problems with the oem 2 piece 2 mm seals. As in, seal failure at levels above 10 psi. I have these suckers in my motor and am looking to dyno/tune in the near future, and don't feel like pulling the motor apart unless i absolutely have to.

If running the oem 2 pc 2 mm seals, please post up miles on your motor, boost levels run, and details on your exhaust portwork if you have that info available to you.

Any other comments/observations from you engine builders out there would also be appreciated

 

I was running them on my stock motor at 13psi of boost without any problems. I put a single on and will be tuning to 15psi shortly.

 

stock mazda seals are rated to handle 20 pounds of boost. You can call a mazda dealership and they can even tell you that in the parts dept. But it all comes down to how many miles your motor has on it, if its ever been over heated, and just how it's been driven in general. But if it's a fresh motor then boosting is no problem. We do it all the time on our motors, the most we ever boost is about 16-17 pounds on the FC's, with an aftermarket turbo of course. Just make sure your getting enough fuel.

 

I can't stress enough how important I feel a proper Air/ fuel ratio gauge is. A good one though like a Haltech or something, not the autometer ones. Also an Exhaust Gas Temperature(EGT) gauge. Key cmponents to actually be able to see if everything is good while running.

 

Don't take this the wrong way, but I am looking for data points--that is, people running these seals. Preaching for newbies has no place in this thread. The importance of an EGT gauge and proper A/F gauge with 4 wire o2 sensor goes without saying.

Mazda parts people in general know next to nothing about modded rotaries, Ray Crowe being the exception.

You talk about "our" motors, can you please furnish details? Type of portwork , race/street, which seals you are using.

These seals are failing, under AFRs in the mid 10s and conservative timing. The old 3 piece seals held up just fine. I have seen it first hand. Ask Judge Ito, ask Chris Rogers, ask Steve Kan. Something is not right, and I am hoping to get to the bottom of it.

 

I think the people who responded in this thread were thinking of the 3-piece seals that originally came in all '86-02 engines...

 

Ahh, more talk of the 2 piece 2mm seals.

I used the new seals in my last rebuild. I only drove the car about 4k miles before selling it, but the engine held up great to routine 20psi bursts. During tuning, there was an issue with the wastegate that allowed the motor to see about 24psi of boost on a few occasions. The above was done all on pump gas.

The motor had a very large streetport, lower compression rotors (which allowed for the higher boost), Mazda Motorsport competition bearings, locked rotors, 2 additional dowel pins and a modified oil jet that allowed for higher oil pressure.

Fast forward 8 months, when the new owner of the car called me, stating that the engine had blown. He drove the car for a little over 2 months and probably racked up another 3k miles. From my conversations with him, the engine failue was not due to the seals, but rather because of his spark plug change. I had the car tuned to run all 9's and he put in the factory 7's and 9's (despite the written instructions otherwise). The motor blew the first time he took the car out after the plug change.

I believe he also accidently crossed the spark plug wires based on some of his questions, but don't know for sure.

Anyhow, that's my report on the seals' durability. I think they are fine, personally. To recap, they held up very well to 20psi on pump gas during the several months I drove the car and a handful of times up to 24psi on pump gas during tuning.
Best,
John

 

Choosing apex seals is not only an issue of boost. Also consider what happens when detonation occurs at said boost. In agreement with everyone else who responded to this thread, the stock seals should suffice. Don't call Ianetti just yet .

 

I don't think the issue was the design of the seals but rather if the recent batches of seals were defected. I have build quite a bit of engines in the past few years and only two engines came back with the seal issue. These engines that has issues were recently purchased from mazda and was ported by me (within 2 months) and diagnose with the same symptons. I haven't changed my porting or my tuning habit. Most of these engines that I build gets tuned by me so why would some seals warped while others don't? I think the recent batches of seals were defected (not laser treated somehow?) It's really hard to say for now because I really think there's a bad batch out there somewhere (how many??). I also think that these bad batches came from the time when Mazda had the reman engine on backordered indefinately (for the past 4months?). Only time will tell if there're other people out there with this issue.

 

Read the second post from goodfella.
It can be seen how you clock up so many posts in such little time.

 

I've been running them for quite awhile over year 18-20lbs no issues I've run them higher as well on brief occasions no issues, I have to agree with the fact it is probably a poor batch as I also have been using them in customer cars no issues as well, some with very aggresive exhaust ports, some on methanol, most in the 15-17lb on pump gas range though.

 

Stock 13bt never rebuilt. I make around 250 RWHP.
street i run 12-14 psi, but i have run 17 a few times.
engine came from japan, probably about 40-60k total miles.
it has seen 12 psi for 3 years.

CJG

 

Then it does not have the 2mm 2-piece seals.

The 2mm 2-piece seals are a "new" thing that Mazda is selling, they no longer produce the 2mm 3-piece seals. Beginning several months ago (maybe it's a year already?) the 3-piece seals have been discontinued, superceded by 2-piece, and it is with these "new" 2-piece seals that people are having problems.

 

I know of a couple people that are running the seals without any problems. Just to name one, 'DirectFreak' on the forum have been using them at 17psi just around 400rwhp without any problems.

 

i think its been about a year, they came out in the summer

 

I've put 50k at 14-15psi on stock seals. That motor was yanked for a coolant seal.

 

I'm running 19lbs with no problems.

 

50K in on the stock seals....must be the old 3 piece since the 2 piece is somewhat new (about a year roughly).

Tim

 

Mine are running great. Running between 15-17 psi on pump gas, on the street.

 

*sigh*

If you have any engine from '86 to '02 (this is all FC, FD, 20B, 13B-RE) with the original seals in it, then it has the three piece seals.

The two-piece seals ONLY went into production WELL AFTER the last RX-7 came off the assembly line, and the last Cosmos were produced long before that.

 

5K Miles...at up to 24psi. All on pump 94.

 

You're telling me that you have run 24 psi on 94 octane?

 

Actually I've ran 23-24psi on 93 octance before but I didnt realize it was that high. I figure the turbos were outside of thier eff range and not really making anymore air flow. If didnt detonate and I was making full 4th gear runs at the time. It was very cold at the time and I was running 8C air intake temps, normally running a turbo outside its eff range super heats the air but I thuogh maybe it wasnt super hot due to the very cold ambient temps.

I just dont know any other way to explain it lol

 

PJ,

If you're referring to me - I know this information.

I recently rebuilt and ported my 13B-RE Cosmo engine with the new 2 piece seals.

 

Well, so far I have ~3200 miles on my 2 piece 2 mm OEM seals. About half of that is a cross-country trip with constant 80-90 mph cruising, no boost. The seals have seen a peak of 12 psi and 342 rwhp, and spent a couple of hours on the dyno for tuning. Many 3rd and 4th gear pulls to redline. Everything seems ok thus far, *knock on wood.* I bought my seals way back in February, so I am beginning to think that what happened was indeed a bad batch. Of course, I have not really cranked up the boost yet either.......