' just finished the engineering-rich "The Wankel Rotary Engine, a history" by John Hege...



upon reading this thread and recomposing myself --- ten year brake pads and "no problem" apex seals--- i recovered enough to give you some helpful advice.



get your self a good patent attorney and call 1 800 mazda.



if you can do something better than their materials engineering company i am sure they would be delighted to pay you guys the big bucks.



just don't spend the money before you see the check. i do genuinely respect you optimism however.



howard coleman

No but im sure they tested a few considering that they were using a chilling process in production that was not even comonly availably in laboratories at the time.



Having said this though from looking at the microstructure of the mazda 3pc seal there is definitly potential to have a material with similar performance (wear and friction) but be much tougher



The black areas are graphite flakes, these being the main reason for the seals to being brittle. This graphite does not have anything to do with reducing friction or wear of the seal but it is likely that it helps prevent galling

Self lubricating and brake rotor don't belong in the same paragraph? On brake pads, they call it friction material for a reason.

Has anyone ever made or tried to make titanium apex seals????

bad idea mike I hate Ti the only good Ti is Thai food. Titainum sucks everybody, get over it. use carbon fiber https://www.nopistons.com/forums/pub...#>/biggrin.png



Oh, by the way, CE7 is garbage, JE tried making pistons out of it, the wrist pin would pull out the bottom of the piston. it would stick in the bores, even with a teflon coating on the skirts. TOOO much expansion properties and holding the proper piston to wall tolerances was damn near impossible without comprimising (sp) ring end gap/seal

titanium is not the all mighty metal that everyone thinks of. Titanium is not good in sheer along it's matrix.



Where it's at is still ceramic in my opinion. I'm not familar with it so I can't comment much, but if you can find a way to manufacture it cheaply then you'd be rich.

When you say too much expansion properties Im assuming that you mean the thermal expansion is too low, its about half that of a high silicone piston alloy, its is also alot weaker (ultimate tensile strength). Sticking to bores is strange though. I have been using this as a piston seal material with no problems like that, do you know what sort of bores they were running them in?.



As for Ti I'm also not that fond of it but did manage to get it to work well in the engine that I have been involved with the development of the biggest advantage was the reduction in weight by abouy 40% over a steel seal, the problem was that the seal would destroy the side plates and chamber coatings once it hard worn to a certain degree, also the manufacturing costs were high

they always scuffed up bad on the skirts cheese. We tried Nikasil, Durasil, good ol' iron bores in a pinto ff2000 block, everything. I stick with what works. I'm not an engineer, im an engine builder. I've seen stock seals hold up to 2 seasons of ENDURO (5-24 hours) racing with a 20B turbo in the back of a GTP car (vintage) about avg 15psi boost bursts of 25.

The main motivation for making my own seals is primarily cost, the second reason that I don't think mazda made 1pce 3mm seals that were not carbon.



Interesting about the CE7 though slightly different applications/operating conditions I guess. It won't work for apex seals only bought it up because it is a slightly exotic material along the lines of the Al graphite that was first mentioned.

This is a picture of the piston with the CE7 seals fitted. It is being run on various plasma sprayed coatings that are used in automotive engines.

why would you want 1piece seals? the whole point of the 2 peice seal, is so it can accomidate the seals change in length with heating/cooling. they stopped using a 1peice in the production cars because they sucked on the street.