NRS FD Ceramic Seals for the RX8

[Kane]

Originally Posted by TitaniumTT

Do you know what the failure rate is for milling them deeper for use in earlier 13B engines? I'm assuming that's the milling that you did have performed, correct?

I did have it performed by Speedsource. I do not know that the failure rating is - but I know it's pretty low.

Originally Posted by thewird

Is what your referring to a machining error? As it needs to be a very accurate/precise machining process? So it being the machinists fault and not the rotor itself?

When machining an FD rotor to 3mm, there have been many cases where machinists don't get it spot on and trash the rotors. But this has to do with the machinist you go to. Once you find the right machinist, trashing rotors is no longer a problem.

Just trying to figure out why. Thanks.

thewird

Kevin can better answer that question - obviously 99.999% of the time is machining or material defects.... nothing technically should prevent you from running a 3mm seal in a RX8 - I just was unwilling to take the risk since 8 rotors are pretty expensive.

[thewird]

Originally Posted by Kane

Kevin can better answer that question - obviously 99.999% of the time is machining or material defects.... nothing technically should prevent you from running a 3mm seal in a RX8 - I just was unwilling to take the risk since 8 rotors are pretty expensive.

Thanks, that's what I wanted to know. My builder knows a good machinist that always gets it bang on so I don't have to worry about the RX-8. Was worried there was something that specifically was different on the RX-8 rotor that prevented 3mm from happening.

thewird

[glassman]

A customer of mine in Russia is looking at running 3mm full height ceramic seals in RX8 rotors. Below is a pic of an RX8 rotor cut away showing the meat available in the slot as well as a stock RX8 rotor for comparison. Please note the cut away slot is not standard RX8 depth because they were using apex seals that are in between OEM height (FD) and RX8 height at 3mm width. Their slot in the cut away is 8.80mm or 0.3464", the total meat available is 12.20mm or 0.4803". This leaves approx 0.1339" to the bottom of the casting. The full height slot should be 0.385" deep leaving 0.0953" of meat remaining, almost 100 thou. From the picture the slot would be deepened another 0.0386", less than 1mm.

Hopefully this info will help others to make a solid decision when considering 3mm full height seals in RX8 rotors.

Thanks Dmitry for this excellent info!