The seals gave while at WOT and 160+ mph. This was a new rebuild that had been through 4000 miles or so of hard driving before dying on me. I had just filled the tank with some noname crappy gas about 40 miles before this happened. I prefer to blame the crappy gas rather than my DIY rebuild and tuning.

2 of the small broken pieces stayed in their slot, and one vanished into the ether without too much drama. In fact, I was still getting decent compression on one face. There was some slight gouging on the housing, and 2 dents on the rotor. The plates and turbos seem untouched. This was the front rotor and 2mm Mazda seals. Boost was around 14psi on stock turbos. Please see the below pictures for damage.

-Is this typical to see 3 break in the same spot like this?
-Does this appear to be a detonation issue or did I screw up the rebuild?
-The rotor appears to be reusable. I'm more worried about the end of the slot getting messed up when the piece ejected than with the dent. Any comments/advice?
-The housing seems to be borderline. Any comments/advice?


Thanks in advance.

 

i see you're in california. my advice is to junk it.

 

Those look like typical detonation breaks.I have attached some pictures of my failed RX8 rear rotor apex seals.
I scrapped both rotor and housing.

 

your car is screwed.. i agree ..JUNK IT..

 

To those just saying 'junk it,' on what do you base your post? Not very helpful.

To the OP:

Re: the rotor housing, you could file down the high spots and maybe get away with using it, but I honestly wouldnt use that in a boosted performance build.

Re: the rotor, I'd recommend cleaning up the seal groove and using a feeler gauge set along with an apex seal along the groove to determine how out of spec it is. You can always sell it cheap to someone who will have it milled to 3mm.

If you need a replacement rotor and/or housing, shoot me a PM, I have both in used but good shape.

 

unless it's my eyes, that rotor looks pretty damaged near the apex (the 2nd scrap on the picture -- looks like a chunk was taken out of it)



edit. I'm talking about the 2nd batch of photos u posted.

 

Uh,he did not post the second set,I did and they are out of my RX8.

 

sorry to see all that work destroyed. out of curiosity what was the extend of your modifications and fuel system tuning? Were you running 91

 

my engine gave out at 160+ as well. have not taken it apart yet though

 

What kind of timing (leading advance, split) and AFR were you running when this happened?

 

Six Rotors - Your break looks to be exactly like mine. I think I narrowly missed gouging out the slot on my rotor though, which appears to have happened to you.

Rich - I may take you up on at least the housing. Thanks. I'll send a PM after I get a measure of the slots on the rotor per your advice.

Monsterbox - I was still on the stock turbos with 1300cc secondary injectors, and a Walbro 255. Failure of the secondary on that rotor is a possibility I think. It was 91, but from a pretty budget weird little gas station.

arghx - This actually happened about 2 years ago (I've finally budgeted a rebuild), and my memory is a bit sketch on the tuning. I do remember it was very conservative and rich, without agressive timing. I had tuned it on the safe side and was thinking of trying to get more power of it since things had been going well for a bit when it blew. I was not logging at the time. The plugs I just pulled indicate it was indeed pretty rich.

Mostly I'm surprised to see all 3 seals break in the same place at once. There dosen't seem to be any evidence that the first break caused the other two seals to go either.

 

a friend of mine did this a few years ago, 160mph+14psi generates a LOT of heat energy add in some unknown quality fuel, and boom...

the average FD isnt really equipped to do full throttle for that much time.

stock car will do 155, but its making less power, and the tune is really rich (mine pegged the dyno wb @10:1)

up the power, and you need to up the cooling too

 

2 or 3 of my seals were broken, and they were all broken exactly like that.

 

I agree. With the exception of the housing. That little nick is so close to the end of the combustion cycle, it probably would have no effect on HP.