Cracked side seals can really only be caused by two things; incorrect clearances or heat stress during the clearancing phase of assembly. I had a set break even though I cleranced them to the upper end of Mazda's spec. I put it down to the fact that I ground down the ends on a bench grinder and must have heat-stressed the ends too much. All the assembly notes I had read to that point (including the FSM) didn't warn against grinding the seals to size. I wasn't until I read that old Mazda document about Criteria for parts replacement in rotary engines, that I finally saw a recommendation that the seals should be cut first, then lightly filed to final size.

 

Side seals were reused from the previous 100,000 mile engine, so it was not clearance or heat stress. Engine was just broken in when I cut the power to the secondary.

 

Voted for Mazda.

 

I know of many places that use little grinders to size the
side seals. didnt think that it would be a problem, i have
always sized them with sand paper the kind with the
sticky side, then stick it to the bench, this keeps it in one
place while sanding.

matt

 

i just rebuilt my motor with mazda 3pc seals, if more like when i rebuild my motor again i will be going with the RA seals. mainly because of scathcart's testamoney. hell if they can handle 12psi and half the fuel, and not mess up the houseing, thats good enough in my book, i know if i did that to my motor now i would be buying a new houseing.

-Daniel