See my broken Apex seals here
 

Hi,

I recently had my FD3 rebuilt. I ordered apex seals, springs and gaskets from Rotechniks in the UK.

The Apex seals were of a 1 piece type, unlike the 3 piece type that were in there before. the part number he supplied was N3F1 11C00. I thought nothing of it because they are reputed Rotary specialists and the bag was labelled genuine Mazda parts.

Can anyone confirm if this is right.

Reasons for my questions...

I pushed up the boost too high and broke 3 seals. A picture of the seals is here:

http://66.223.106.85/trevsrx7/apex-seals.jpg

What I would like to know is should I look for 3 piece seals like I had before my first rebuild? And were these seals I bought in any way partly to blame for the breakage (i.e. Not FD3 apex seals etc)


Note: Number 3 seal in my picture is nearly what the thing looked like new, minus a small piece which broke off the end. I can only pray it didn't do much damage flying through the turbine, and the housing and rotores were undamaged.


Thanks


trevor

FD3 Type R2 1994 Japan.

Hmm....

I'm curious to know why the apex seals broke roughly down the center, as if it was a 2 piece apex seal? Also, note, how apex seal #1 and #2 broke in roughly the same spot.

http://66.223.106.85/trevsrx7/apex-seals.jpg

detonation

I have not had good experiences with rotechniks. As to the seals, factory 2mm ones are all 2-piece again unless my brain is mangled. 1-piece are usually (in UK) hurley ones.

Be that as it may, there is something horribly wrong with your setup to cause that sort of damage.

Bill

Had another think about it, and that damage very much smacks of a clearancing issue. Viz: if there was not enough clearance in the apex groove, it would have formed an interferance fit with the rotor when it got hot. Fixed this in place, it would then snap off as the rotor when round.

Bill

Hi Bill,

thanks for your thoughts. Could you explain what an interference fit is. And/or what I should be looking out for when putting in the new seals this time.

An interference fit is when a peg expands to be bigger than the hole it is in. Or in this case the seal is wider than the groove it sits in.

I can't comment on the clearances that apex seals need as I haven't the experience, but any reputable engine builder, or the supplier of those seals will be able to tell you.

Bill