Coeficient of friction would depend on a number of variables; seal finish, characteristics of the mating materials, lubrication, temperature, pressure etc.
I am not aware of any controlled tests for COF with ceramic seals against the hard chrome of the rotor housing. However several speed shops have seen gains of 20 ft lbs of torque (1 piece) and 25 ft lbs of torque(2 piece) when switching from steel seals (normally asperated).

Hardness (Gray) 1650 Vickers- 10kg load
(Black) 1560 Vickers-10kg load
Thermal Conductivity
(Gray) @ 20 Celsius- 65 (Wm/K)
(Black) @ 25 Celsius- 25.6 (Wm/K)
Fracture Toughness
(Gray) @ 20 Celsius- 8.0 (MPam1/2)
(Black) @ 20 Celsius- 6.4 (MPam1/2)

 

so they grey material has greater conductivity than steel?, thats just awesome, the black material is very nice for ceramic aswell.

 

Glassman:
Please forward the information on the both seal types.

An honest question here, what advantages/disadvantages do these seals have over the Ianettis ceramic seals? Beyond cost of course. Any direct comparison data points? Just curious.

Thanks,

-Bern
brhslm@earthlink.net

 

Question is, what's going to keep the coolant seals alive that long if by somehow this really is a breakthrough in Apex seal design???

 

Its funny what time and experiences will do to someone ideas haha

If you see this, I'm just playing with ya man

Whoops, sorry guys didnt mean to pull from the dead, I was doing a search and forgot haha

STEPHEN

 

imy stock seals were at .295 (new is .315) after 140,000 miles, also na.

so assuming linear wear my stock 3pc 2mm's would have been worn .006" after 40,000miles.

 

I have a coolant seal available that will last that long.

 

Seeing as though this is a year old, and many others have asked, can we get some kind of follow up and what over the last year have results been?

~Mike.............

 

Hello all! It's been some time since I gave you an update on the ceramic apex seal testing. I have been very busy producing seals and it's hard to find time for anything else. It's also hard to find customers willing to share their results. I have recently established a distributor for the Australia/New Zealand region and we have some real world testing to share with you. One of our "down under" clients is Rohan Ambrose of X-Treme Rotaries. Rohan has done with a rotary and ski boat what many said would never work. Not enough torque, cant handle the stresses etc.

Below are links for downloading videos of a ski boat with a 20B.

Peter Giljevic (Rice Racing/NRS Australian Distributor) tells me that Rohan wanted to push the NRS Ceramic Power Seals to the X-Treme limits therefore they were installed in the rear rotors. Here's how it is: Mazda Speed ceramic seals in the front rotor and NRS Ceramic Power Seals in the center with the NRS chamfer to 2mm seals in the rear rotor. This test lasted about 35 minutes at wide open throttle. Very cool!!



February 16 2005 update: The test results have been backed up by another grueling session of 26 minutes at full throttle and 9500 RPM @ 22 psi.

Rohan tells me that the stresses on the internals of the engine are approximately double of what the same engine would see in a car, especially when the boat comes out of the water under boost and then slams back down.

Here are some spec's on the boat:



- Hull - Kevlar 1850 bullet, Bravo 1 XR leg

- Engine – X-Treme Rotaries 1962cc 20B (3 rotor) rotary engine, bridge ported, turbocharged, fuel injected

- Horsepower – 800hp 9500rpm 615 ft/lbs torque

- Speed – max 120mph 9650rpm

- Tuning – by Anthony Rodrigues, Maztech of Melbourne

- Turbo – Garret GT42 1000hp

- Intercooler – PWR barrel water to air

This link will take you to Ausrotary.http://ausrotary.dntinternet.com/fo...pic.php?t=57587. The thread is worth the read!!



Here are the links for downloading the videos of the ski boat.

http://www.xtremerotaries.com/boatvideo/roh_boat_1.wmv
http://www.xtremerotaries.com/boatvideo/roh_boat_2.wmv
http://www.xtremerotaries.com/boatvideo/roh_boat_3.wmv

Enjoy!!!

 

I just tried this one lets see if this works.
http://ausrotary.dntinternet.com/for...ic.php?t=57587.

 

This one seems to work. There are some more vids to download on page 3 of the thread.

 

Also, I did not know there was a problem with wearing out apex seal springs, whats the life expectancy of a set of stock and your "spray hardened" springs on say a really hard driven 13bt making 440 hp at the wheels mileage wise?

~Mike.........

 

Yes they come in two grades and the seals in the ski boat are the premium seals.


There was a definite problem with wear on the springs until I developed the hard faced springs. The ceramic material is very hard and the spring quite soft in relation to each other. So even when the seal is polished to 1200 grit diamond polish finish the springs are completely worn out at 5000 miles or perhaps sooner. That just happens to be when I tore the engine down. I was running a 2 pc seal and the wedge piece was only resting on the tip of the sharpened spring. There was no outward or upward push at all.

In the past ceramic seals were primarily used by racers so 5000 miles would not be a problem for anyone using them for this purpose. The problem arises when you want to use them on the street. Who wants to tear down the engine in their daily driver every 5000 miles max? A solution was needed in order to even consider serving this market. The pictures below will speak for themselves. After 7000 miles I measured a 0.001" loss to the tip of the spring and it appeared to have just burnished nicely. The coating is applied at around 0.006" (could be more but is unnecessary).







As for life expectancy, I would only be guessing at this point. I have these same seals and springs back in the engine and have added another 5730 miles for a total of 12,730 miles to date. The seals themselves have over 56,000 miles on them. I will not tear the engine down again for at least another year or maybe two.
Regards,
glassman

 

whats the difference between the two grades.... why would someone want the inferior grade? or is the better grade just more for racers?

 

The black material was chosen to be marketed for street use. Even being inferior to the grey material it is superior to that of a steel seal. Racers using carbon apex seals would definitely benefit from the black seals and for many street applications the black material is fine. In high reving N/A engines either seal will perform beautifully but the grey material could be considered overkill. It's when you start to push the envelope that you want the grey seals or if you simply want the best there is. The black seals are more affordable and the savings can be put towards the hard faced springs or to opening the grooves for 3mm seals. The point of offering two materials is to give you the consumer the choice to buy a seal to meet your needs.

The fracture toughness of the grey material is about 25% higher. Thermal shock ability of the grey material is 1100 degrees Celsius/ 2012 degrees Fahrenheit and the black is 600 degrees Celsius/ 1112 degrees Fahrenheit. Meaning the material is heated to these temperatures and then submersed in room temperature water without breakage. Maximum continious temperature use for the grey material is 1400 degrees Celsius/ 2552 degrees Fahrenheit and the black material is 1100 degrees Celsius/ 2012 degrees Fahrenheit.
I hope this helps.
Regards,
glassman

 

Please, anyone visiting the website remember that some of the info there is dated and some of the spec's have changed. The site shows pics of an early type (prototype) seal that is no longer being made.

Also no one has commented on the ski boat!! I hope there is not a problem downloading the videos. I would really like to hear what everyone thinks.
Happy Trails,
glassman

 

Any chance of the spring hardening being done to 2mm springs?

Do you recommend using 3mm seals when the proper rotor machining is within engine budget?

 

Yes the hard facing can be done to 2mm springs and yes I would recommend using 3mm seals where possible. They are much stronger and would save a costly upgrade to them at a later time if needed.

 

hmm lots of interesting ideas/opnions and facts... I am still looking at them all, anyone with factory or some hardcore tests/ offical tests please let me know I am interested in results

thanks =)

 

Did you check out the ski boat? Some hard core testing there.

 

I saw vids of the boat a few months ago and i have to say that would be one of the more extreme tests for any engine. 9000rpm for 45min is not something to be taken lightly! Has the engine been apart and if so how did the 2 types of seal compare?

 

Yes the engine has been apart and the NRS seals are as expected "perfect".

NRS ceramic power seals are as recently as this weekend being implemetend in some top flight PROrwd Australian rotaries and again nothing but the best will be experienced and enjoyed by end users....

Quality,
Reliable Function,
&
Durability...

They are that good I bought the company LOL :P

RICE RACING
NRS Australasia Region

 

Out of curiosity are the seals in the Australian engines being run with a mineral or synthetic oil (I'm guessing that they would be premixed)

 

I really don't know. If you drop Rohan an email I'm sure he could tell you.

 

Just I've been doing some testing/research with different materials and found that some types of oils can cause a chemical type of wear on some ceramics, most oils seem to be fomulated specifically for iron based materials