have bdc or ito used the rotary aviation apex seals and what do you guys think about them

Still in my engine. Still going strong.

the clock starts in 2.5months https://www.nopistons.com/forums/pub...#>/biggrin.png

Got mine yesterday, deciding which engine to use them in.

Yep they work well. We're enjoying them.



B

I'm confused? How come in 2.5 months? I've had them in 3 different engine's.

They're in my buddy's Turbo II, they take a beating... still going strong

I tested a set out of my own curiousity...

I built an engine using one of their kits, and then installed a switch onto the rear rotor secondary injector, and cut the injector off at 12 psi and 5000 rpm.

Obviously, this induced some detonation https://www.nopistons.com/forums/pub...#>/biggrin.png



The rear endplate crakced, all of the corner seals broke, and 5 side seals broke near the upper ends of them. ONE apex seal cracked where the corner piece meets the "long" section of the seals, at the corner of the longer piece.

The apex seal stayed in the groove, and the chunk remained in position.



I emailed Rotary Aviation to ask to purchase another seal and a few other parts to rebuild the engine, and they were shocked to hear it failed at all, despite the conditions I described. They offered to replace the seals for free. I declined, simply b/c its not fair to charge them when I was simply testing the seals against detonation. Despite my request against it, they mailed me a FULL set of replacement seals for free, and told me the ones I tested were a weaker preliminary version (I tested their seals with the single apex sealsprings; the new ones come with dual springs like stock.



These seals are fantastic. I have them in a couple engines, with one holding 20psi. Under extreme detonation in each rotor combustion face, only one of the seals let go, and all of the other faces must have experienced detonation, and this was on their "crappy" seals.



RWS's service is fantastic. They make a good product at a fair price (although I don't really like the fitment of the SAE viton oil control o-rings).



The seals, however, take a long time to break in. I find peak compression is achieved at 5000 miles on used, good condition rotor housings.

Woah. That's amazing!

Scathcart,



When you tore that engine down did you notice any abnormal wear to the housings? Or too much wear is what I am getting out? Induced detonation aside of course https://www.nopistons.com/forums/pub...#>/biggrin.png

I while ago I saw someone who ran a motor with high boost and stock injectors.. He had dents in the rotors from the detonation.. I am curious if you saw anything like that too?

Slight dent in the face that the seal broke in.



I tore down an engine with 12,000 miles on it and did not find any abnormal wear on brand new housings using these seals in a turbo half-bridge.

What type of damage did they do to the exhaust housing? I'm VERY impressed with these seals so far. Good testing scathcart!

Nothing. The seals remained in their grooves, one just cracked.

Any pics of the damage?

If you really want it, I suppose I could do it. Its not very exciting... a pic of a bunch of broken seals all sitting together and an iron cracked on the dowel pin?

Did it do any damage to the rotor?

i'm down for pics

No real damage other than the slight dent.

I'll consider grabbing some pics this weekend... though I have no other real reason to head to the shop until the insurance cuts me a check and I can replace all of my stolen tools.

Good to hear. Must go check to see if I have a preliminary set.... https://www.nopistons.com/forums/pub..._DIR#>/sad.png

That is a great story to hear for those of us with the RA two-spring seals installed. https://www.nopistons.com/forums/pub...IR#>/bigok.gif



Thanks for sharing.

There's been alot of buzz about these seals on the forums but no real data to date

until now. I just recently tore down an engine that we were building for a race-type of auto application using these 2mm 2-piece seals as a test after about 4,500 miles of use (almost all street-driven and highway).



I cleaned up the apex seals and measured two of them. I measured 0.309" and 0.310" in heighth respectively and widths of 1.93mm. I'm not sure what their stock heighth is, but if these are manufactured to stock specs then that's only 0.005" to 0.006" of wear! An equivalent seal, a 3mm 2-piece (presumably stock but unsure) design with twice the miles shows 0.293 and 0.295" of total heighth, a full 0.015" shorter!



So far, I give them a huge thumbs up. They're hard as rocks but not too hard for the rotor housing apparently. I noticed that, upon disassembly, the steel lining of the rotor housing was nearly mirror finish on both of them. I'm not sure if these seals have anything to do with that but I find it odd because these housings are not new.



The only potential long-term issue that I might see happening (thanks for mentioning this, Mike!) is accelerated wear of the "pressure" side of the rotor's apex seal groove -> the part of the groove that the apex seal is constantly pushes up against. I regret that I didn't measure the apex seals when they were new and I also didn't measure the both rotors' apex seal grooves before or after so I have no numbers for you guys here. I apologize for this.



I'm looking forward to using these seals more most definitely.



B

Are you measuring height at the center? I'll measure a set I have.



I didn't get pictures this weekend, but I plan on it this week, around thurs evening.

I measure at the edges of the inner (short) apex seal springs.



B