What Apex seal to use?
07-13-11, 03:31 PM
#201
It's clearly a tune related issue...
07-13-11, 04:28 PM
#202
"Elusive, not deceptive!”
I thought that the softer seals would be wearing and bending in that direction... that is up from the housing surface or possibly even rearward.
The whole seal problem as I see it is really an issue of dealing with an integral design problem in Rotaries.
This problem causes harder seals to crack and softer seals to bend. So must we just go on choosing what we think is the best compromise to mask the problem? Or should we look for the root-cause?
I like T-von’s idea of working together to solve the problem. We have people here with lots of experience and knowledge if we just had a way of harnessing it into a working group.
Barry
07-13-11, 05:26 PM
#203
Thanks Enzo,
I thought that the softer seals would be wearing and bending in that direction... that is up from the housing surface or possibly even rearward.
The whole seal problem as I see it is really an issue of dealing with an integral design problem in Rotaries.
This problem causes harder seals to crack and softer seals to bend. So must we just go on choosing what we think is the best compromise to mask the problem? Or should we look for the root-cause?
I like T-von’s idea of working together to solve the problem. We have people here with lots of experience and knowledge if we just had a way of harnessing it into a working group.
Barry
I thought that the softer seals would be wearing and bending in that direction... that is up from the housing surface or possibly even rearward.
The whole seal problem as I see it is really an issue of dealing with an integral design problem in Rotaries.
This problem causes harder seals to crack and softer seals to bend. So must we just go on choosing what we think is the best compromise to mask the problem? Or should we look for the root-cause?
I like T-von’s idea of working together to solve the problem. We have people here with lots of experience and knowledge if we just had a way of harnessing it into a working group.
Barry
Everyone wonders why rotarys are a dieing breed. Its because most people who do know something out there have a stick in there ***. And i admit I AM ONE of them as for example i am rebuilding a rotary engine for a guy locally and i priced him $2400 for a full rebuilt and ported turbo block and rebuilt turbo. well he has fought me the whole way saying that "well i called BANZAI RACING and they can get me the exact motor that your building me for $1700 shipped with no core charge"(which we all know is not true) Its people like that who make people who do know a thing or two so hostile and not want to help anyone.
You can spend hours answering peoples questions and giving out information out only for the next guy to say that is wrong and his **** is bigger.
I WILL SAY THIS I DO TUNE MYSELF AND YES I MAKE GOOD POWER ON 2 ROTORS 500+WHP BUT YOU HAVE TO KNOW WHAT YOUR DOING AND WHEN YOU PUSH THE ENGINE MORE AND MORE, IT REQUIRES MORE EXPERIENCE THEN MOST REALIZE. TUNING IS EVERYTHING
07-13-11, 05:50 PM
#204
So if you have irregular combustion taking place it's the seal that absorbs that..
So fix the problem. Don't try to mask it..
07-13-11, 06:37 PM
#205
"Elusive, not deceptive!”
And as for irregular combustion... unfortunately, I am afraid that is the signature of the Rotary. We can only make it as close to regular as possible.
Barry
07-13-11, 07:47 PM
#206
07-13-11, 08:14 PM
#207
"Elusive, not deceptive!”
I was referring to the pressure and temp when the exhaust port opens.
Best peak pressure I have seen is 1000 psi. (at 12 psi boost, where I test).
Since it varies with boost, you may well be at 2000 psi.
Barry
07-13-11, 08:38 PM
#208
"Elusive, not deceptive!”
Let’s put our thinking caps on.
When I was young and had a problem, my dad would tell me,” let’s put our thinking caps on”.
What we know relating to the problem of Apex seal failure.
-Soft seal bend.
-Hard seals crack.
-We have a high wear spot on the housing at the spark plugs.
-Cold sparkplugs help.
-Higher power makes it worst.
-Mazda’s manual mentions apex seal wear at the center of the face.
-Mazda also mentions expansion type wear on the housing width at the spark plugs.
Other possibilities that may contribute to the problem.
-Cavitation of the water pump from a poor impeller design and/or too high RPM.
-Unbalanced water flow through housings.
This is what I think is the smoking gun.
Barry
When I was young and had a problem, my dad would tell me,” let’s put our thinking caps on”.
What we know relating to the problem of Apex seal failure.
-Soft seal bend.
-Hard seals crack.
-We have a high wear spot on the housing at the spark plugs.
-Cold sparkplugs help.
-Higher power makes it worst.
-Mazda’s manual mentions apex seal wear at the center of the face.
-Mazda also mentions expansion type wear on the housing width at the spark plugs.
Other possibilities that may contribute to the problem.
-Cavitation of the water pump from a poor impeller design and/or too high RPM.
-Unbalanced water flow through housings.
This is what I think is the smoking gun.
Barry
07-13-11, 11:25 PM
#212
i agree but anything that involves a rotary attracts a different kind of people. Helping others is too easy and may take away business. money money money. Lots of people out there ask questions and usually get the answer " take it to someone who knows".
Everyone wonders why rotarys are a dieing breed. Its because most people who do know something out there have a stick in there ***. And i admit I AM ONE of them as for example i am rebuilding a rotary engine for a guy locally and i priced him $2400 for a full rebuilt and ported turbo block and rebuilt turbo. well he has fought me the whole way saying that "well i called BANZAI RACING and they can get me the exact motor that your building me for $1700 shipped with no core charge"(which we all know is not true) Its people like that who make people who do know a thing or two so hostile and not want to help anyone.
You can spend hours answering peoples questions and giving out information out only for the next guy to say that is wrong and his **** is bigger.
I WILL SAY THIS I DO TUNE MYSELF AND YES I MAKE GOOD POWER ON 2 ROTORS 500+WHP BUT YOU HAVE TO KNOW WHAT YOUR DOING AND WHEN YOU PUSH THE ENGINE MORE AND MORE, IT REQUIRES MORE EXPERIENCE THEN MOST REALIZE. TUNING IS EVERYTHING
Everyone wonders why rotarys are a dieing breed. Its because most people who do know something out there have a stick in there ***. And i admit I AM ONE of them as for example i am rebuilding a rotary engine for a guy locally and i priced him $2400 for a full rebuilt and ported turbo block and rebuilt turbo. well he has fought me the whole way saying that "well i called BANZAI RACING and they can get me the exact motor that your building me for $1700 shipped with no core charge"(which we all know is not true) Its people like that who make people who do know a thing or two so hostile and not want to help anyone.
You can spend hours answering peoples questions and giving out information out only for the next guy to say that is wrong and his **** is bigger.
I WILL SAY THIS I DO TUNE MYSELF AND YES I MAKE GOOD POWER ON 2 ROTORS 500+WHP BUT YOU HAVE TO KNOW WHAT YOUR DOING AND WHEN YOU PUSH THE ENGINE MORE AND MORE, IT REQUIRES MORE EXPERIENCE THEN MOST REALIZE. TUNING IS EVERYTHING
My comments about helping don't have anything to do with who rebuild engines or who is cheaper ect. My main concern is taking the research/R&D knowledge that's already out there and actually posting findings on specific apex seal limits. Zero's own admission to what he feels is the limits on those particular apex seals is very helpful info to others. A perfect tune can't cancel out limitations in specific parts.(like some would believe). Whether you believe this or not, WE are all part of this rotary experiment. I've said this before, Mazda can't do all the R&D themselves. Apex seals have always been the achilles heal when it comes to engine damage. The better WE understand the limits, the less blown engines and the better the reputation rotary's get.
07-13-11, 11:56 PM
#213
4th string e-armchair QB
iTrader: (11)
Join Date: May 2005
Location: North Bay, Ontario
Posts: 2,745
Likes: 0
Received 0 Likes
on
0 Posts
Right, but there is no quantifiable evidence that the experience Ernie has is the limit as he says it is. If someone else was to go through more than one set of any seals at a lower power level and said that "These seals simply will not work at xxx power level" everyone would throw the book at them. Correlation is not causation; just because A led to B, does not mean that it caused it. And on top of that did we forget that NRS is not the only ceramic apex seal manufacturer? There's also that other guy, you know, Ianetti...
07-14-11, 12:31 AM
#214
My comments about helping don't have anything to do with who rebuild engines or who is cheaper ect. My main concern is taking the research/R&D knowledge that's already out there and actually posting findings on specific apex seal limits. Zero's own admission to what he feels is the limits on those particular apex seals is very helpful info to others. A perfect tune can't cancel out limitations in specific parts.(like some would believe). Whether you believe this or not, WE are all part of this rotary experiment. I've said this before, Mazda can't do all the R&D themselves. Apex seals have always been the achilles heal when it comes to engine damage. The better WE understand the limits, the less blown engines and the better the reputation rotary's get.
I am also not saying that tuning can get you 2000hp on a stock motor. Yes everything has limitations but tuning is a huge factor.
It would be nice if everyone would help yes and i get that and you have a good suggestion but it never works out like that.
07-14-11, 10:46 AM
#215
"Elusive, not deceptive!”
The solution would be to keep the sparkplug surface as flat as possible.
In this picture the housing was using hard seals (OEM).
With hard seals their shape would be better on most of the housing but will rock over the hump loosing compression. This rocking will finally cause failure at the seal’s sharp end from high cycle fatigue.
With soft seals they will conform better to the sparkplug hump but lose their sealing efficiency on the rest of the housing surface. My guess would be that they not as prone to sharp tip breakage.
Both scenarios of leaking gases can cause blow-back into the following fresh charge causing preignition.
07-14-11, 12:34 PM
#216
Exactly rx7king,
The solution would be to keep the sparkplug surface as flat as possible.
In this picture the housing was using hard seals (OEM).
With hard seals their shape would be better on most of the housing but will rock over the hump loosing compression. This rocking will finally cause failure at the seal’s sharp end from high cycle fatigue.
With soft seals they will conform better to the sparkplug hump but lose their sealing efficiency on the rest of the housing surface. My guess would be that they not as prone to sharp tip breakage.
Both scenarios of leaking gases can cause blow-back into the following fresh charge causing preignition.
The solution would be to keep the sparkplug surface as flat as possible.
In this picture the housing was using hard seals (OEM).
With hard seals their shape would be better on most of the housing but will rock over the hump loosing compression. This rocking will finally cause failure at the seal’s sharp end from high cycle fatigue.
With soft seals they will conform better to the sparkplug hump but lose their sealing efficiency on the rest of the housing surface. My guess would be that they not as prone to sharp tip breakage.
Both scenarios of leaking gases can cause blow-back into the following fresh charge causing preignition.
at different temperatures....some one needs to make a one piece housing...
07-15-11, 10:55 AM
#217
07-18-11, 05:50 AM
#219
Rotary Freak
Barry the rotary by it's design will always leak gases from 1 chamber into the next chamber coming along. You have 2 apex seals sealing up 1 chamber on the rotor, when the apex seal goes over the trailing spark plug hole, gases will leak under the apex seal through the trailing and leading holes into the next chamber. nothing we could do about that. another issue the rotary has is, top dead center cooling off. on a piston engine the spark plugs and the TDC area get a chance to cool off when the piston engine is in the EXHAUST cycle. the exhaust valve opens and releases the wasted gas, while this is happening the TDC area and the spark plugs get a chance to cool off. Not the case on a rotary engine, TDC on a rotary is always dealing with high temperatures and never getting the chance to cool off since the exhaust stroke is taken somewhere else to exit the engine. that is 1 of the many reasons why rotary engine spark plugs always cost more vs piston engine spark plugs. a rotary engine spark plug never gets a chance to cool off during it's exhaust cycle like a piston engine. the minute anybody puts a cold heat range spark plug on a rotary, the engine gets happy. why? simple the cold heat range spark plug is absorbing some of the elevetated heat in the top dead center area. but yes barry your on the right track. a good tune and a way to lower top dead center temperatures and we have a happier rotary engine..
07-18-11, 06:03 AM
#220
Rotary Freak
Enzo breaking and fixing any engine is frustrating enough. Ernie has been a part of our community for ages. regardless of what ever he said or you said or anybody has said. let's keep in mind that none of us including Ernie need the added frustration. in general we come here to vent. and every so often learn something.
07-18-11, 11:38 PM
#221
Enzo breaking and fixing any engine is frustrating enough. Ernie has been a part of our community for ages. regardless of what ever he said or you said or anybody has said. let's keep in mind that none of us including Ernie need the added frustration. in general we come here to vent. and every so often learn something.
My points exactly!
07-19-11, 12:23 AM
#222
talking head
i wonder if motec saw that tech bulletin regards the trailing timing ping when they setup the down spec ecu's to use no-split one channel per rotor
( leading and trailing fire together )
i think not,,,,
here is my question ( or is it answer ? )
anybody ever tried moving the end of injection point in earlier so as to achieve a more uniform chamber mix at the problem rpm?
methinks this is one of the keys to avoiding the mixture stratification that pushes all the undesirable mixes to the trailing end of the chamber
also,, i know you guys joke about it,, but for me,, loosing maybe 5 hp from deleting the trailing spark at problem rpms is far better than guessing and still rebuilding motors
maybe use the aux out ( or knock box ) and a relay to bridge 12v to the ( - ) post on the trailing coil during the problematic boost and rpm points to disable it without discharging the coil
BTW,,, i run much closer to lambda under load than most of you,, i run no trailing timing,, instead rely on wastespark leading
( significantly later than the normal trailing timing )
the reason is simple,,, i have LPG fuel,, it is far more uniform in mixture throughout the chamber
no matter what was done with trailing timing,, light diesel pre-ignition would occur with high inlet manifold temps
delete,, problem solved
lambda1 at idle,, lambda 1 at part load,,, 12.5 :1 under high boost
-- homogeneous charge is the difference ,, ask audi how they won so many times without AI, running close to lambda at load
and lastly-- 100% alco mix,,,WTF- reinventing the wheel ?
when 70 water / 30 meth is going to do MUCH more for the chamber and inlet and exhaust temps
ask the germans,, MW-50 ( for high altitude ,, antifreeze ) and MW 30
-----they found out the hard way ,, fast
( leading and trailing fire together )
i think not,,,,
here is my question ( or is it answer ? )
anybody ever tried moving the end of injection point in earlier so as to achieve a more uniform chamber mix at the problem rpm?
methinks this is one of the keys to avoiding the mixture stratification that pushes all the undesirable mixes to the trailing end of the chamber
also,, i know you guys joke about it,, but for me,, loosing maybe 5 hp from deleting the trailing spark at problem rpms is far better than guessing and still rebuilding motors
maybe use the aux out ( or knock box ) and a relay to bridge 12v to the ( - ) post on the trailing coil during the problematic boost and rpm points to disable it without discharging the coil
BTW,,, i run much closer to lambda under load than most of you,, i run no trailing timing,, instead rely on wastespark leading
( significantly later than the normal trailing timing )
the reason is simple,,, i have LPG fuel,, it is far more uniform in mixture throughout the chamber
no matter what was done with trailing timing,, light diesel pre-ignition would occur with high inlet manifold temps
delete,, problem solved
lambda1 at idle,, lambda 1 at part load,,, 12.5 :1 under high boost
-- homogeneous charge is the difference ,, ask audi how they won so many times without AI, running close to lambda at load
and lastly-- 100% alco mix,,,WTF- reinventing the wheel ?
when 70 water / 30 meth is going to do MUCH more for the chamber and inlet and exhaust temps
ask the germans,, MW-50 ( for high altitude ,, antifreeze ) and MW 30
-----they found out the hard way ,, fast
07-24-11, 09:08 PM
#225
Stay tuned...
iTrader: (3)
Join Date: Jul 1997
Location: West Islip, Long Island NY
Posts: 2,917
Likes: 0
Received 1 Like
on
1 Post
Here are some more details on the above video...
RXParts Apex Seals
RXParts 2 Piece E-shaft
RXParts Engine Stud Kit
GTXR 4202 71mm turbo
Electromotive TEC3R
PFSupercars built/tuned 13B Semi PPort
Visit http://www.rxparts.com for more info on the Apex Seals...
RXParts Apex Seals
RXParts 2 Piece E-shaft
RXParts Engine Stud Kit
GTXR 4202 71mm turbo
Electromotive TEC3R
PFSupercars built/tuned 13B Semi PPort
Visit http://www.rxparts.com for more info on the Apex Seals...