rotor apex seals slots got too wide
 

Hi,
Year ago I bought 14000miles 2008 Rx8. Its compression was about 127PSI.
Its superb! :-)
About week ago I started to hear strange ‘tick, tick’ sound which was correlated to RPM (more RPM, more tick,ticks).
Compression test showed 90PSI…:(
The car has 22500 miles now, I mostly use it on public roads with track day once a quarter.

The engine inside looks like brand new with one exception - apex seal slot in rotor has enlarged so apex skewed (attachment).
Now, rotors and apex seals will be replaced BUT there are still two questions

1. Why did it happen?
Was it bad rotor material or my driving style?
Ive heard that rapid RPMs reductions could cause that. I personally love my car high RPMs sound so its not seldom when I accelerate at 2nd/3rd gear till 9kRPM and then release the throttle so I could hear that lovely(!) sound. Anyway I can't just accelerate, sometimes I need to lift of the throttle:)
Ive heard as well that ‘aggressive engine braking with gear downshifting’ could cause that as well. While aggresive braking I use heel and toe technique so its rather considered smooth braking.

2. What to do to not repeat such failure in future?
This strongly depends on answer on 1st question but lets assume its my driving style and I don’t want to change it.
Deeper rotor slots with taller apex seals so they will be better held by rotor? Ive read some posts around it but Im afraid about cutting precision.
Are there any other options?

Thanks!

PS. To Admin - Ive just registered - could you please unlock me or move this thread to 'series 1 troubleshooting'? Thx!

Wow , never heard of that issue even on high mileage 8s . Is it just one slot on one rotor or are they all like that ?
If it's just one slot , I would put it down to a tolerancing error from the factory . If it's on all slots on both rotors .............. :dunno:
Deeper slots per the Rx7 is possible but it's normally only useful for those of us running a turbo.

Uhmmmmmmm. Why are you replacing individual engine parts? The engine is still under warranty until 2016, right? (2008+8 years)

IMO, I don't see how your driving style could have caused this over 8500 miles. I'd say either this is a manufacturing defect of some sort, or there was some kind of physical impact on that one seal over and over. Are the other seals in the same rotor like this? Why is the right edge of the rotor (in the picture) all jagged after the apex seal? Were the spark plugs changed incorrectly by chance?

that seems to be in the rotor's design.
http://atkinsrotary.com/store/images/P/Rx8Rotor-01.jpg

Both rotors, all slots. More wider or less but all.

Im in Europe, so we have different warranty - engine is out and open so its over anyway.

Spark plugs - don't think so. Since Ive bought it its serviced in my local Rx8 gurus or Mazda dealer.

Any thoughts what the heck could cause that?

Goopy sells oversize (wider) apex seals for rx7's that have this issue too.

Renny has 2mm right?
http://www.goopyperformance.com/html/goopy_performance_apex_seals.html

Ive heard that goopy is a decent upgrade for boosted applications but I also heard that they use a harder apex material than oem which is tough on chrome finish of the housings

I haven't heard that about them, I am using deeper rx7 goopy apex seals currently

Thread moved to appropriate forum.
OP, thanks for asking.