Mazda going back to a 3 piece apex seal???
 

Just heard from a solid source, that if you use the part number for the 2 piece 2mm apex seal it has been changed to a 3 piece 2mm apex seal...

Makes me wish i hadn't let my brand new set of 2mm 2 piece seals go...

Discuss.

i have not heard anything about 3 piece seals, i would just stick to the aircraft 2mm seals, they work great.

You can try calling Ray Crowe to confirm.

Mazda has gone back and forth with certain designs over the years: for example, the coolant seals were located on the rotor housings until 85, then they were put on the irons, and now they are back on the housings for the Renesis. Now there's nothing inherently wrong with a 3 piece seal, but it needs to be stronger than the older ones that came factory on the FD without compromising housing life. Recall that a 3 piece seal is designed to seal better than a 2 piece:

https://www.rx7club.com/attachment.p...1&d=1263938145

RE Amemiya uses 3 peice seals as an upgrade also. Maybe this might be a change, hopefully for the better.

3 piece are fine when new and have their advantages. They seal really well and are easy on the housings. The only problem I have with them is how brittle they get as they age. As the top piece gets shorter, it also make the seal more prone to breaking. Plus they carbon lock much easier than 2 piece seals as the bottom piece will get stuck leaving the top piece to just bounce around and not make compression. Mazda needs to stop screwing around and just go with ceramics.

They should just get them from NRS!

I can say this much, last time I ordered seals (11/09) I used part number N3F1-11-C00 and I got 3-piece seals. It was going in a stock 6-port build so I was not disappointed at all.

Last year when my remod engine die on my finally (loss compression on rear rotor) since I installed in in Jan 0f 96, I thought it had normal 2 piece seal, to my surprise it had the 3 piece seal however the front housing were still making 7.5, 7.6, 7.8 compression from the mazda digital compression tester, I guess 3 piece might have a longer life.
Khris