No problems here.

any more updates?

Maybe on your overloaded FD engines. My until-recently-daily-driven RX-7 had over three times that amount on its engine. Then I pulled it and put a ported engine in, reusing *all* of the internals, which had only 119k on them after all and were still in spec. (well, except for the housings, but oh well!). The original engine is still going strong, and it'll go back in when the next emissions test is due. Or maybe it will become the core for my next engine build, who knows? Internals are probably still in spec at only 184k miles.

N/A rotary.

I cant believe anyone would build an engine, use new/ newer housings and the old apex seals.

Contact JHB. I know that when they were doing testing for their ceramics they blew the hell out of one of the irons and dowels. Ask them what seals they used and how they faired after the engine blew.

- Steiner

If he's talking about a 12A or 13b from the 1st gen, it can be done if the seals aren't warped. NA those seals damn near last forever. Those older 2 piece seals are alot more durable than those POS 3 piece design that Mazda came out with.

I am talking about the imperfect apex edge that runs on the rotor housing
if the housings had to be replaced (they were not in spec) then the running edge
of the old apex seal were not flat and will not match up to the new / newer housing
all this ends up doing is damage to the new housings.
matt

I guess I missed the part where he was using new housings.

Glassman , which ones of your seals best suits 20B with 30PSI of boost? 3mm gray 1 piece?

Exactly!

So how are the corner an side seals surviving in all these cases? I mean if the seals are holding up that well, shouldn't the stress go to something else?

what happened to glassman's last post? there was a nice little bit of info of how some of his seals are holding up.

Yeah, I actually remember there being a good bit more to this thread yesterday afternoon... not just one post more either.

No I was wondering about the other engines in your deleted post that had detonation and survived. I understood that the apex seals were holding up. I was wondering how the side and corner seals survived during this detonation since the apex seals never gave out?

Oh, that I'm not sure of. I will try and find out. Being so far away from the source I get bits and pieces of data.

Thanks

Good question....
I've re-writtin this post 3 times, and still cant get it right to not come off as an ass so I am omitting what I really want to know....

I was wondering how in all of these detonation/preignition events that the seals held up to-

none of the iron side housings cracked at the dowel areas?

Were all the motors seriously doweled as well? I have seen pics of FD housings crumbled at the front top dowel and earlier housings at the rear top dowel.

Anyways, I am glad to hear all the good reports and amazingly I haven't heard ANY negative reports -besides, ouch that hurt the wallet :)

Pretty soon ceramics will be the standard apex seal material.

Here's one that took some damage. Ever seen one this bad? The e-shaft key was almost sheared in two. This is from a 1000 hp 13B drag engine. NRS Ceramic Power Seals lived and yes some side seals were damaged. This is not one of the cars from AU.


http://img.photobucket.com/albums/v4...Housing002.jpg

Strange cracking on that one!

The combustion side looks fine and the dowel areas undamaged?

Do those cracks emminate out from the rear stationary gear mounting holes on the rear of the plate?

Not so strange when you know what happened to it. Someone must have been pretty tired when this was done. After an MSD was installed the trailing plug wires were mistakingly installed reversed! I guess we all have our moments.

The cracks were easily visable before being disassembled but I didn't get a shot of the rear view so I don't know where they exactly line up on the outside.

Well I just had my second near death experience (well with my engine that is).
Awhile back I had some serious detonation that cracked the rear dowell at the oil filter pedastal. Seals held up fine. One piece 3mm greys were in the engine.

The seals did let go though on the next build when the tuner (not Steve Kan btw) inadvertantly advanced the timing 16-18 degrees on top of normal timing as a result of a misdiagnosed problem. The front rotor let go and obviously all the seals there were wasted. The weird thing was is that after it popped, we checked the rear rotors compression first as that is usually the one that lets go and the compression was perfect on all faces. Then, upon taking the engine apart, we discovered one of the seals on the rear rotor had a clean break through it. Not a scratch on the rotor housing or any sign of damage. Obviously some bad shit was happening inside that engine.
Needless to say, no seal could have survived.

https://www.rx7club.com/forum/attach...d=136144&stc=1

Next on the list was just this last weekend. I was running 91 octane and did the first full power run on the dyno. Quickly found out that the wastegate was stuck closed and the boost shot up to 28 psi according to the Haltech. Steve let of the throttle at 5300 rpm as obviously there was something wrong. We thought there was a mistake with the Haltech sensor or software and then checked the Profec B which read 29.4 lbs. This engine also has the 1-piece 3mm greys.

Compression and vacuum are still just like a new engine. I won't own another rebuilt rotary engine without ceramics.

Here's a pic of the key.

http://img.photobucket.com/albums/v4.../Keyway-sm.jpg

Not to start anything, but just wanted to say that's not the case at all. I had a motor let go exactly how you say, cracked by the oil filler neck, and my 2mm mazda seals held up just fine. I've also seen the exact same thing 2 other times on S4 blocks, it's pretty common for them to break right there and not break seals.

I'm pretty sure he meant no seal could have survived the 16-18 deg advance in timing that the motor was subjected to.


The seals did let go though on the next build when the tuner (not Steve Kan btw) inadvertantly advanced the timing 16-18 degrees on top of normal timing as a result of a misdiagnosed problem. The front rotor let go and obviously all the seals there were wasted. The weird thing was is that after it popped, we checked the rear rotors compression first as that is usually the one that lets go and the compression was perfect on all faces. Then, upon taking the engine apart, we discovered one of the seals on the rear rotor had a clean break through it. Not a scratch on the rotor housing or any sign of damage. Obviously some bad shit was happening inside that engine.

Exactly