Apex Seals - How many pieces

[leeroy_25]

I have been doing some research! and I see that over the years the rotor motors have gone from 3 pieces to 2 pieces and then what looks like 1 piece on the RX8? What is the reason for them being split to begin with? is it to allow oil feed into the housing? What is the best seal to use if you are going for a rebuild? 1 piece or two piece?
Thank you
Lee

[antnicuk]

the rx8\'s use 2 piece as does the FD, Mazda used to use 3 piece then to 2 piece, these are the best.  I piece are better for race use and high rpm as compression isnt that good at low rpm.

The have a diagnal split to allow for expansion

[Grizzly]

just don\'t use 3pc

I think there swapped to 2mm 2pc quite a while ago? This is the most commonly used seals, all depends on what you are after but as long at you stick with Mazda OE seals you can\'t go far wrong (that goes for Springs too, VERY important there OE)

1 pc are usaly only top end so you are looking at ceramics

[Draco]

ok then what about hte differnace between 2mm and 3mm seals? whats better for a rebuild/ 400bhp rwhp and where to get?

[Sidzrx]

From my understanding 2mm seals, seal better but the 3mm seals are better/ more tolerant for high boost applications

[antnicuk]

2mm all the way, people only used 3mm because the were 2 piece when mazda only made 2mm 3 piece. Now they make 2mm 2 piece, 3mm are redundant.  They are made from different material and were never designed for turbo applications.

Mazda 2mm springs and seals run 9 seconds on the quarter,  i think that says it all,

[leeroy_25]

Thanks guys, Some good info!! I get the split now!! I knew there was a good reason for it somewhere! Should have thought about that a bit more.. was obvious when you said it!

Lee

[Grizzly]

ok then what about hte differnace between 2mm and 3mm seals? whats better for a rebuild/ 400bhp rwhp and where to get?

OOO this question is like opening a can of Worms. There are people out there that swear by 2pc 3mm seals as people think they handle Det better, thing is Det can crush rotors and do some really serious Damage so the idea is not to get it in the first place. (do a search on here and some of the US forums, you will find lots about this subject)

2mm seals are defo the way to go, the way i see it the heavier the seal the Harder it Pushes against the Housing at higher RPM (centrifugal force) this is why people use lighter Seals in High rpm engines (as the extra Friction at High RPM has been known to warp apex\'s), next the 2mm seals as said to seal better at low rpm because of there contact area (not to sure it makes allot of difference and i\'ve never see proof of this).

TBH on a road car i\'ve driven cars with 2mm\'s and 3mm\'s and there is no noticeable difference, the Difference comes if you use After market Springs, then you find they flatten out over time causing lower compression.

And my Fave... If Mazda (who spends Millions on R&D) dropped the 3mm in favor of the 2mm and uses Ceramics in there race engines then who are we to argue