NRS Rotorsports ceramic seal test results
03-03-06, 03:02 AM
#78
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Originally Posted by RX-Heven
Well I just had my second near death experience (well with my engine that is).
Awhile back I had some serious detonation that cracked the rear dowell at the oil filter pedastal. Seals held up fine. One piece 3mm greys were in the engine.
The seals did let go though on the next build when the tuner (not Steve Kan btw) inadvertantly advanced the timing 16-18 degrees on top of normal timing as a result of a misdiagnosed problem. The front rotor let go and obviously all the seals there were wasted. The weird thing was is that after it popped, we checked the rear rotors compression first as that is usually the one that lets go and the compression was perfect on all faces. Then, upon taking the engine apart, we discovered one of the seals on the rear rotor had a clean break through it. Not a scratch on the rotor housing or any sign of damage. Obviously some bad **** was happening inside that engine.
Needless to say, no seal could have survived.
Next on the list was just this last weekend. I was running 91 octane and did the first full power run on the dyno. Quickly found out that the wastegate was stuck closed and the boost shot up to 28 psi according to the Haltech. Steve let of the throttle at 5300 rpm as obviously there was something wrong. We thought there was a mistake with the Haltech sensor or software and then checked the Profec B which read 29.4 lbs. This engine also has the 1-piece 3mm greys.
Compression and vacuum are still just like a new engine. I won't own another rebuilt rotary engine without ceramics.
Awhile back I had some serious detonation that cracked the rear dowell at the oil filter pedastal. Seals held up fine. One piece 3mm greys were in the engine.
The seals did let go though on the next build when the tuner (not Steve Kan btw) inadvertantly advanced the timing 16-18 degrees on top of normal timing as a result of a misdiagnosed problem. The front rotor let go and obviously all the seals there were wasted. The weird thing was is that after it popped, we checked the rear rotors compression first as that is usually the one that lets go and the compression was perfect on all faces. Then, upon taking the engine apart, we discovered one of the seals on the rear rotor had a clean break through it. Not a scratch on the rotor housing or any sign of damage. Obviously some bad **** was happening inside that engine.
Needless to say, no seal could have survived.
Next on the list was just this last weekend. I was running 91 octane and did the first full power run on the dyno. Quickly found out that the wastegate was stuck closed and the boost shot up to 28 psi according to the Haltech. Steve let of the throttle at 5300 rpm as obviously there was something wrong. We thought there was a mistake with the Haltech sensor or software and then checked the Profec B which read 29.4 lbs. This engine also has the 1-piece 3mm greys.
Compression and vacuum are still just like a new engine. I won't own another rebuilt rotary engine without ceramics.
03-03-06, 03:04 AM
#79
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Originally Posted by BOOSTD 7
Not to start anything, but just wanted to say that's not the case at all. I had a motor let go exactly how you say, cracked by the oil filler neck, and my 2mm mazda seals held up just fine. I've also seen the exact same thing 2 other times on S4 blocks, it's pretty common for them to break right there and not break seals.
a friend brought his car over the other day... fired up fine, all seals intact....cracked front iron. it happens, but i think it's safe to say the ceramics are stronger--even if that wasn't the perfect example.
03-08-06, 02:55 AM
#80
Can't wait to see what crispeed has to say.
Seems great. But I dunno if I would want to spend more than the base 1 piece black seals.
No way I'm spending double that for the optioned out seals!
Thats the only way to fly, check off every option box!
-Ben Martin
Seems great. But I dunno if I would want to spend more than the base 1 piece black seals.
No way I'm spending double that for the optioned out seals!
Thats the only way to fly, check off every option box!
-Ben Martin
03-10-06, 05:21 AM
#81
Originally Posted by Node
Can't wait to see what crispeed has to say.
Seems great. But I dunno if I would want to spend more than the base 1 piece black seals.
No way I'm spending double that for the optioned out seals!
Thats the only way to fly, check off every option box!
-Ben Martin
Seems great. But I dunno if I would want to spend more than the base 1 piece black seals.
No way I'm spending double that for the optioned out seals!
Thats the only way to fly, check off every option box!
-Ben Martin
Initial crank and start-up went just about perfect. It kicked over right away. After about one hour of idling the vacum is about two inches stronger allready.
After some more idling about 25 gallons of fuel worth
the vacum is the same or just a little better than with factory 3mm apex seals. Also hot re-strart is perfect.I'm going to give it a couple hundred miles of break in on the street and do the rest on a load dyno at the same time doing light load/cruise tuning.
After I'm going to do a compression check. I was told to give the ceramics some extra time to let them seat before applying full load so a couple hundred more miles and they should be ready for some abuse!
Last edited by crispeed; 03-10-06 at 05:27 AM.
03-10-06, 10:33 AM
#83
Originally Posted by GUITARJUNKIE28
how long did it take to go through 25 gallons of fuel idling?
03-10-06, 03:32 PM
#85
What RX-Heven said, plus what else was done to the engine (porting etc)?
You mentioned it pulls the same or a little better vacuum than the 3mm, what was the reading taken at or around the same point after a rebuild? Or was that from the last time it was run? Do you have values? What was the 3mm engine running corner seal, rotor housing wise? I assumne you were running factory apex seal springs. Were the factory 3mm one piece or two?
From talking with many engine builders that used ceramic seals say they take longer to break in.
You mentioned it pulls the same or a little better vacuum than the 3mm, what was the reading taken at or around the same point after a rebuild? Or was that from the last time it was run? Do you have values? What was the 3mm engine running corner seal, rotor housing wise? I assumne you were running factory apex seal springs. Were the factory 3mm one piece or two?
From talking with many engine builders that used ceramic seals say they take longer to break in.
Last edited by eyecandy; 03-10-06 at 03:34 PM.
03-10-06, 09:53 PM
#86
I assumne you were running factory apex seal springs
I hope he is using the NRS chrome plated springs otherwise the back of the ceramic seals will wear the springs down so that there is no compression in ~20,000 miles on the street.
Which brings up an idea I had a bit ago.
Instead of the chrome plated springs why not make a thin stamped metal piece to back the ceramic apex seals that the spring can ride against? It can be bonded to the seal for easy assembly.
Even with the chrome plated springs, in the pics provided as evidence of their worth it doesn't appear the springs would hold up to 200,000+ miles like stock springs on stock seals.
Ian
I hope he is using the NRS chrome plated springs otherwise the back of the ceramic seals will wear the springs down so that there is no compression in ~20,000 miles on the street.
Which brings up an idea I had a bit ago.
Instead of the chrome plated springs why not make a thin stamped metal piece to back the ceramic apex seals that the spring can ride against? It can be bonded to the seal for easy assembly.
Even with the chrome plated springs, in the pics provided as evidence of their worth it doesn't appear the springs would hold up to 200,000+ miles like stock springs on stock seals.
Ian
03-11-06, 05:13 PM
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Originally Posted by couturemarc
NRS offers cermet tipped springs to solve this problem, they are long lasting.
05-27-06, 07:43 PM
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Originally Posted by yodaddy
they don't have them for 2mm yet though, so something still needs to be figured out for that.
05-30-06, 07:44 PM
#91
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Wear is always there and dependant upon the hardness of the materials. One thing that always stands out though is total wear, across two running pieces, will split upon thier appearant hardness.
My point is: You now have a virtaully non wearing seal. What happens to the apex seal groove? I believe it then recieves 100% of the wear.
I guess maybe some guys get rotors cheap enough! It must be OK. Has any one experimented with hardening the groove?
My point is: You now have a virtaully non wearing seal. What happens to the apex seal groove? I believe it then recieves 100% of the wear.
I guess maybe some guys get rotors cheap enough! It must be OK. Has any one experimented with hardening the groove?
05-30-06, 08:09 PM
#92
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[QUOTE=TonyD89]
My point is: You now have a virtaully non wearing seal. What happens to the apex seal groove? I believe it then recieves 100% of the wear.
QUOTE]
Actually it's quite the contrary, the grooves notice less wear due to friction reduction once the seal polishes where it contacts the groove. This is one of the primary reasons ceramic seals were approved for the Formula Mazda Series. With standard steel seals the grooves were wearing in some cases in one race event. The wear was enough to note power losses on the dyno 3 - 7 hp off a minimum fresh engine. When ceramic seals were used the wear was virtually eliminated.
My point is: You now have a virtaully non wearing seal. What happens to the apex seal groove? I believe it then recieves 100% of the wear.
QUOTE]
Actually it's quite the contrary, the grooves notice less wear due to friction reduction once the seal polishes where it contacts the groove. This is one of the primary reasons ceramic seals were approved for the Formula Mazda Series. With standard steel seals the grooves were wearing in some cases in one race event. The wear was enough to note power losses on the dyno 3 - 7 hp off a minimum fresh engine. When ceramic seals were used the wear was virtually eliminated.
05-30-06, 09:31 PM
#93
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^Surface quality has a huge impact when using such incredibly different hardnesses, I just was wondering if the real world was holding up.
05-30-06, 09:31 PM
#94
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The softer material will always suffer.
05-31-06, 12:20 PM
#95
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Tony,
I have heard things about these seals that are too good to be true in the real world. They were from what I consider to be very reliable sources. I purchased a set myself and in a few months I will post regarding my experiences.
John
I have heard things about these seals that are too good to be true in the real world. They were from what I consider to be very reliable sources. I purchased a set myself and in a few months I will post regarding my experiences.
John
05-31-06, 02:56 PM
#96
mad scientist
Originally Posted by TonyD89
Wear is always there and dependant upon the hardness of the materials. One thing that always stands out though is total wear, across two running pieces, will split upon thier appearant hardness.
My point is: You now have a virtaully non wearing seal. What happens to the apex seal groove? I believe it then recieves 100% of the wear.
I guess maybe some guys get rotors cheap enough! It must be OK. Has any one experimented with hardening the groove?
My point is: You now have a virtaully non wearing seal. What happens to the apex seal groove? I believe it then recieves 100% of the wear.
I guess maybe some guys get rotors cheap enough! It must be OK. Has any one experimented with hardening the groove?
Wear is a direct result of friction. Oiled ceramic has a considerably lower coefficient of friction that oiled steel. Less friction = less wear on everything.
06-01-06, 09:25 AM
#97
Originally Posted by Jodeny
Tony,
I have heard things about these seals that are too good to be true in the real world. They were from what I consider to be very reliable sources. I purchased a set myself and in a few months I will post regarding my experiences.
John
I have heard things about these seals that are too good to be true in the real world. They were from what I consider to be very reliable sources. I purchased a set myself and in a few months I will post regarding my experiences.
John
Real world results..
Just under 2000 miles of sustained abuse at 685rwhp with perfect compression.
Full report comming soon!
06-01-06, 05:04 PM
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Originally Posted by mazdaspeed7
Wear is a direct result of friction. Oiled ceramic has a considerably lower coefficient of friction that oiled steel. Less friction = less wear on everything.
06-01-06, 05:36 PM
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Originally Posted by Glassman
the mass of the seal increases exponentially.