So I've got a '93 13REW that I'm rebuilding. I just found the culprit (as I suspected) to be an apex seal.


This is what happened:




I'm open to theory's and comments.

I believe my fuel pump leaned out under high boost and rpm. I've got a Walbro 255lph, PFC, Twinpower, 1680 injectors etc, etc. Running 15 psi on 99'spec twins.

Were the stock apex seals 3-piece?

 

Yep, detonation...
Chipped "corners" is one of the symptoms.
That largish piece that "broke off" on the other end is a sign of SERIOUS detonation.

Yeah, the original seals should be all 3-piece.
Mazda changed to a 2-piece design somewhere in the mid 90's to late 90's.
If you order apex seals now, they are all 2-piece.


-Ted

 

Preventative Measures:
(0) When you tune your engine, do timing in cold weather. Do AFRS in winter and summer to set up Air Temp vs INJ table.
(1) Install a fuel pressure gauge and verify your on boost fuel pressure from time to time.
(2) About twice a year, verify on boost AFRs.
(3) After each gas tank refill, watch at lease one on boost knock levels.
(4) Allow IC temps to stabalize before getting on boost if car had hot soaked parked for a while.

 

Use Aviation seals next time. No more chipped seals.

 

Or just do what Chuck said. If you can afford it go ceramics.

 

well actually I took Blake's advice. I got the Hurley seals while I'm learning to tune. When I get the tune right with the gt35 I'm going to upgrade to, I'm gonna go Ianetti ceramics through Mazdaspeed. I imagine that I'll do that within a year so I want to minimize the risk of detonating real hard and throwing big chunks of seal through the turbos. Once I get comfortable with the tune, I'll put the ceramics in there.

 

Good deal, I'm just waiting on the next NRS shipment

 

So I think the side housing is gouged pretty good on the front rotor. What are my options?

Can I get it resurfaced or do I have to get a whole new piece?

 

Extra Info: The plate in question has .002 step wear at the corner of the football.