Judge Ito

I recently build a 3rd gen. engine using the new 2 piece 2mm Mazda oem apex seals. Before I decided to use these seals I talked to a friend and drag racer that used the seals before me. He told me,that he made more power at less boost with the new mazda seals. I purchased a set and tried them. My drag racing friend broke the new mazda oem seals the same weekend he went racing in a NOPI meet.
Not to long ago my customer dynoed his car with the fresh engine using the new type of apex seals from mazda. and made some decent power before he lost alot of vacuum. The engine has no broken apex seals but is week in vacuum. Ill soon tear the engine apart and Ill check the seals. I have seen this type of lost of vacuum when I used 3mm apex seals Under a load and A/F ratios at 10.5 to 11.3 to 1 apex seals warpped and bended like a banana. I'm thinking the new 2 piece 2mm apex seal is not desinged for high turbo exhaust gas temperatures. Maybe the 3 piece 2mm seals releases and transfers heat faster then the new 2mm ones. has anybody had a similar situation? I was told by my Mazda dealer that most of the engine builders back in the west coast are no longer buying the new 2 piece seals and buying the 3 piece seals again.

RICE RACING

Very Ineresting, this backs up what I have herd but was reluctant to post untill there were more cases.

Its always hard to judge (no pun inteded) based on one result but when a few users have similar experiences then its more likely that there is an "issue"

BTW how long will 3 piece seals be available for ?

Judge Ito

I don't think mazda will go back to the 3 piece seal. I'm almost sure the only 3 piece that are selling are the inventory ones.

CCarlisi

Ito,

I have the new two-piece seals and my motor was also dynoed by the same tuner as your customer. My car was run to 14.2psi of boost on the dyno and ended with the same vac it started with. I put down 313rwhp at about 13psi with afrs in the 10s.

My friend's recently had a ported motor assembled with these seals. His car was tuned with less than 400 miles on the motor to run 22psi on pump gas (jesus!!). That was several weeks ago. Aside from a wastegate problem the motor has held up fine.

I was standing next to your customer's car when it was tuned. I will be very suprised if you find that the failure is due to detonation. There was no audible detonation and the afrs were very conservative. Yet after each run, the motor made less and less vac until it finally stalled and the car was pulled off the dyno.

I hope for the sake of everybody that bought these seals that the problem is not due to a design defect. Given the fact that my friend's motor running 22psi and my motor are in one piece I'm not too concerned yet.

I also want to mention Ito was nice enough to respond to his customer's voice message regarding his motor problem at 10pm on a Saturday night!

Judge Ito

thanks for your input Carlisi. This friday Ill have the car in the shop, Saturday Ill tear the engine apart and Ill post results. Carlisi, Steve told me he heard no sings of detonation and I believe him. The engine has a steady low vacuum, giving the reading of a warpped apex seal. If any type of internal seal was broken the vacuum needle would be all over the place, in this sitiuation is not. making me think theres a faulty apex seal. again thanks for your input.

93 R1

Ito I PM'd you

SPOautos

I wonder if they are heat treated on the edges like the old ones were? How many miles were on the engine when it dynoed?

Could just be that the new design and process is causing some quality control issues and they have some bad seals out there.

STEPHEN

jantore

I also have the new 2 piece seals from mazda. Iv'e been running them for 3000 miles now and they are fine. Pulling a strong vacume. Almost 500 mm/hg.

I did a dyno run 2 weeks ago and it posted 321 rwhp and 280 pounds of Torque.

Im running it at 15 psi on stock twins.

How much psi can i run on the new 2 piece 2mm seals?

SPOautos

at 15psi your only making 321??? What mods do you have? You still have the cat or something?

STEPHEN

jantore

i have
FMIC
full exhaust
air filters
Modified ECU for more fuel.

that's it


but i did have a faulty fuel pump

it was not giving me enough fuel. i will try and get my dyno sheet scanned. oh and this is a wery mean dyno. It's a Dynojet

JScott

Aaaaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrrr rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrggggggggggggggggggg gggggggggggggggggggggggggggghhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I just rebuilt mine, LAST WEEKEND, w/ the new 2pc seals............................................. .........................

JBurer

I'm taking the car back to Carlos to have the exhaust manifold fixed next weekend. Once boost is controllable to a safe level, I'll have dyno results to share.

I've put about 1k miles on the motor since it was tuned and everything seems to be running strong. That said, the engine probably isn't seeing the full heat load (timing isn't very advanced and afr's are in the mid to high 10's under boost). I'd say the engine is putting out close to 450 to the wheels in it's current tune with pump gas. We know that the new seals can hold up to that level.

Fingers crossed for a long-lived engine!

~John
PS Chris, you made it sound like I didn't give the engine a full break-in before tuning. In addition to letting the car idle for an hour or two, I followed the break-in procedures suggested by Mazda Motorsports to the letter.

Maxthe7man

Interesting, what is the break in time like for the new seals, with old and new housings?..
I am using the newer rotary aviation seals in my motor, and so far so good, although they are still are not totally broken into the housings, everytime I compression test, the numbers keep getting higher, I am at about 1500 miles on it right now..Max

JScott

The new ones that are supposed to be SUPER strong? Please keep us updated on your engines health. I hope JBurer's right. I should be fine at 408rwhp then. I too am tuned very mild. High 10's afrs and 13deg's at 15psi.

RETed

I just went through a set for one motor, and I have to build two more.

One thing that REALLY pissed me off is that they are milled for the "smaller" inner apex seal spring - or are you guys running a single apex seal spring?

I had to hand-mill these ******* to make them fit the longer apex seal springs inners off the 13BT.

It's funny, I have 6 shorter inner apex seal springs from an unknown source, so some of the FC's might've been running them. All the 13BT motors I've torn down run the longer inner apex seal spring.

You guys are not doing something as dumb as using the long inner apex seal spring with these new 2-piece apex seals, are you?

Here's a pic...
Parts number tag on top.
Mazda OEM 2-piece seal, unmodified top.
Mazda OEM 2-piece seal, hand-milled by me to fit long apex seal spring inner, middle.
Mazda OEM 3-piece seal, used - notice the groove for the inner apex seal spring.



-Ted

now

iTrader: (1)

this is odd the new n351-11-c00c seals i have,
have the groove as shown in the posted picture but
it matches up 100% with the old 3 piece seals i have
out of old motors, and new out of the package 3 piece.
those old 3 piece seals with the longer spring area
are out of what year motor?

matt

Judge Ito

Ok. I think, I did not learn much here about the new 2 piece 2mm seals. I'll have to give more information about this customers car so we could get a solid answer.
I had ported and polished this engine for a customer but the engine was installed at a different shop. This 3rd gen. had popped a couple of stock engines at the dyno before the new ported engine was installed. I wanted to go over ignition timing before the car was dynoed again with the new engine. The owner of the 3rd gen. brought the car over. I checked the ignition timing and no to my surprise the Power FC's handset commander was reading one ignition timing and the actual timing was way OFF! after one day of checking the power fc for any kind of problem I finally found the problem in the crank angle sensors wires being inverted by the last person that worked on the car.Know the car is dynoed and after some runs the engines loses vacuum and power, at this point the engine is hurt and needs to be pulled out.

I get the car back at my shop and start to pull the engine apart. The first problem I find is the harness wires to the secondary injector to the front rotor broken. The engine was running on 3 injectors, the rear rotor was working on the primary and secondary injectors but the front rotor was working on the primary injector,THE ONE WIRE that was broken to the secondary injector was deep inside the harness,I had to tear the harness back to find this trigger wire..IN MY OPINION THE WIRE TO THE SECONDARY INJECTOR HAD BEEN A PROBLEM FOR A WHILE. I tear the engine apart and find the rear rotor fine and no damage to the apex seals but the front rotor had all 3 apex seals warpped and curled like a banana.

Know I was told the car had no engine miss or engine gasping for fuel at the dyno. But doing my forensic study the engine leaned out really bad in the front rotor. I mean the apex seals are toast to the point that they are purple in color showing extreme internal temperature only in the front rotor.

Basically a mechanical failure not a material failure.

JScott

Well, I'm feeling a collective sigh of relief from all of us new 2pc seal users..... Hope the other "drag" car had some other reason for failure, than the seals, as well. Keep us informed guy's, PLEASE!

I've got nearly 300 miles on mine. I've done a couple 10psi sprints without incident. I'm probably making 340rwhp there. I'll up the boost to 14-15psi, after a few more miles. Wish me luck....

Ted, I used some stk 13BT springs I had. I heard them all snap into place so I'm sure I'm ok. Guess I'm lucky since I never thought of checking that.

vosko

iTrader: (4)

glad to hear the problem was found

RETed

The long springs I know came out of a 1986-1988 turbo. Most of the long springs come out of 1986-1988 engines, including both turbo and non-turbo. Like I said before, I have a bunch of short springs, and we had one 1989-1991 turbo engine apart, but I've kept those pieces on the side and those are all long springs.

I've got to get to the bottom of what engines use the short springs, as the majority of the engines torn down here (I'm working on customer cars in CZ right now) all come out with the long springs - they are all 1986-1988 early model FC3S.


-Ted

now

iTrader: (1)

I am in canada and have never seen this longer short
spring in anything, and i have opened motors from
1986 to 1995.
matt

RETed

Wow, that is weird. I can find only 9 short apex seal springs, but I have no idea where they are from.


-Ted

JScott

Just keeping this one alive. Anybody have any updates on any of the new 2pc, 2mm seals? I upped my boost for a couple runs to 15.5 psi last night. They held fine and that's over 400rwhp. Finger's crossed!

Scott

Judge Ito

In my opinion the seals are just as good as the 3 piece and a bit stronger then the 3 piece seals.

javrosario

iTrader: (5)

Maybe they came out of a 3 rotor motor?