Apex seals - ceramic
03-03-03, 03:13 PM
#26
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Originally posted by RICE RACING
Mat
They were made (the material by CSIRO) it was developed for the mining industry (tips for rock milling equipment) and some bright spark thought they would be great for rotaries !
The only problem is the weight, some of them suffered from poor material quality (the set I bought !) and others were very soft, they tended to chamfer the leading edge at high temperature despite being so hard at normal temperature ?
I ran a few sets, in general I found them to be far inferior to the factory 3mm seal and 2mm seal. Iannetti on the other hand are excellent, they are a similar weight ot a carbon seal ! and I have personaly built engines (and rebuilt) engines running these they cause far lower housing wear but they cost an amazing amount, I believe they do not seal as well as the multi piece 2 mm seal, but they do have other advantages.
Hope this clears things up a bit.
Mat
They were made (the material by CSIRO) it was developed for the mining industry (tips for rock milling equipment) and some bright spark thought they would be great for rotaries !
The only problem is the weight, some of them suffered from poor material quality (the set I bought !) and others were very soft, they tended to chamfer the leading edge at high temperature despite being so hard at normal temperature ?
I ran a few sets, in general I found them to be far inferior to the factory 3mm seal and 2mm seal. Iannetti on the other hand are excellent, they are a similar weight ot a carbon seal ! and I have personaly built engines (and rebuilt) engines running these they cause far lower housing wear but they cost an amazing amount, I believe they do not seal as well as the multi piece 2 mm seal, but they do have other advantages.
Hope this clears things up a bit.
-Hung
03-05-03, 01:28 AM
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Originally posted by RICE RACING
Mat
They were made (the material by CSIRO) it was developed for the mining industry (tips for rock milling equipment) and some bright spark thought they would be great for rotaries !
The only problem is the weight, some of them suffered from poor material quality (the set I bought !) and others were very soft, they tended to chamfer the leading edge at high temperature despite being so hard at normal temperature ?
Mat
They were made (the material by CSIRO) it was developed for the mining industry (tips for rock milling equipment) and some bright spark thought they would be great for rotaries !
The only problem is the weight, some of them suffered from poor material quality (the set I bought !) and others were very soft, they tended to chamfer the leading edge at high temperature despite being so hard at normal temperature ?
Hi Rice,
It sounds very much like the seals you're talking about were made from
"carbide" based materials, which are different than the ceramics used in high-
quality apex seals. Carbides (tungsten, titanium, chromium, etc) are typically
not monolithic materials, but are usually available as powders or granules. A
binder is used to "cement" the powders together (typically cobalt), and this
composite material is diamond ground to a finished shape.
Carbides are typically quite heavy (as Mr. Double found), and can "soften" if
the critical temp of the binder is reached. Ceramics like aluminum oxide or
silicon nitride are made by having the base materials "absorb" oxygen or nitrogen
(as apposed carbon) during the firing that creates them. These base materials
can be molded or cast into complex shapes prior to firing, and even machined first
(ages ago I made experimental spark plugs by machining "green" aluminum oxide
forms to make insulators, which were later fired for final properties).
Al2O3 and Si3N4 are significantly lighter than steel, and have the ability
to be polished to a very fine finish. This, as well as inherent material
properties allows for a very low tribological reaction when rubbing a surface
like a chrome plated rotor housing. I don't know for sure what material Iannetti
uses, but it's likely one of these or a slight variant.
I hope this is of some use, and a small payback for the info I've gotten from your posts...
David Breslau
Widefoot Racing Co.
(not a materials scientist, but I worked with 'em at MIT)
03-05-03, 11:08 AM
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Originally posted by WidefootRacing
Hi Rice,
It sounds very much like the seals you're talking about were made from
"carbide" based materials, which are different than the ceramics used in high-
quality apex seals. Carbides (tungsten, titanium, chromium, etc) are typically
not monolithic materials, but are usually available as powders or granules. A
binder is used to "cement" the powders together (typically cobalt), and this
composite material is diamond ground to a finished shape.
Carbides are typically quite heavy (as Mr. Double found), and can "soften" if
the critical temp of the binder is reached. Ceramics like aluminum oxide or
silicon nitride are made by having the base materials "absorb" oxygen or nitrogen
(as apposed carbon) during the firing that creates them. These base materials
can be molded or cast into complex shapes prior to firing, and even machined first
(ages ago I made experimental spark plugs by machining "green" aluminum oxide
forms to make insulators, which were later fired for final properties).
Al2O3 and Si3N4 are significantly lighter than steel, and have the ability
to be polished to a very fine finish. This, as well as inherent material
properties allows for a very low tribological reaction when rubbing a surface
like a chrome plated rotor housing. I don't know for sure what material Iannetti
uses, but it's likely one of these or a slight variant.
I hope this is of some use, and a small payback for the info I've gotten from your posts...
David Breslau
Widefoot Racing Co.
(not a materials scientist, but I worked with 'em at MIT)
Hi Rice,
It sounds very much like the seals you're talking about were made from
"carbide" based materials, which are different than the ceramics used in high-
quality apex seals. Carbides (tungsten, titanium, chromium, etc) are typically
not monolithic materials, but are usually available as powders or granules. A
binder is used to "cement" the powders together (typically cobalt), and this
composite material is diamond ground to a finished shape.
Carbides are typically quite heavy (as Mr. Double found), and can "soften" if
the critical temp of the binder is reached. Ceramics like aluminum oxide or
silicon nitride are made by having the base materials "absorb" oxygen or nitrogen
(as apposed carbon) during the firing that creates them. These base materials
can be molded or cast into complex shapes prior to firing, and even machined first
(ages ago I made experimental spark plugs by machining "green" aluminum oxide
forms to make insulators, which were later fired for final properties).
Al2O3 and Si3N4 are significantly lighter than steel, and have the ability
to be polished to a very fine finish. This, as well as inherent material
properties allows for a very low tribological reaction when rubbing a surface
like a chrome plated rotor housing. I don't know for sure what material Iannetti
uses, but it's likely one of these or a slight variant.
I hope this is of some use, and a small payback for the info I've gotten from your posts...
David Breslau
Widefoot Racing Co.
(not a materials scientist, but I worked with 'em at MIT)
03-05-03, 11:55 AM
#30
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Originally posted by IgoSlow
Wow... you sound like a damn scientist.. and you attended MIT.. thats an amazing feat in itself.. NERD.. .just picking.. wish i had have the will and smarts to attempt to even get in there... But i'm a bum...
Wow... you sound like a damn scientist.. and you attended MIT.. thats an amazing feat in itself.. NERD.. .just picking.. wish i had have the will and smarts to attempt to even get in there... But i'm a bum...
Heh - I plead guilty to being a (car/science/manufacturing) nerd, but I
want to make it clear that I worked at MIT as a technician and instructor
(still teach part time), but did not go there as a student. It was a lot
of fun to work there (got to build most of a small satellite that's going
strong and getting good data), but can be tough for the kids coming in.
David Breslau
Widefoot Racing Co.
(If being a nerd is wrong, I don't wanna be right...)
03-05-03, 03:35 PM
#31
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Originally posted by WidefootRacing
Heh - I plead guilty to being a (car/science/manufacturing) nerd, but I
want to make it clear that I worked at MIT as a technician and instructor
(still teach part time), but did not go there as a student. It was a lot
of fun to work there (got to build most of a small satellite that's going
strong and getting good data), but can be tough for the kids coming in.
David Breslau
Widefoot Racing Co.
(If being a nerd is wrong, I don't wanna be right...)
Heh - I plead guilty to being a (car/science/manufacturing) nerd, but I
want to make it clear that I worked at MIT as a technician and instructor
(still teach part time), but did not go there as a student. It was a lot
of fun to work there (got to build most of a small satellite that's going
strong and getting good data), but can be tough for the kids coming in.
David Breslau
Widefoot Racing Co.
(If being a nerd is wrong, I don't wanna be right...)
Last edited by IgoSlow; 03-05-03 at 03:40 PM.
01-08-07, 11:56 PM
#34
here is a quote from mazdarotaryclub.com
The Ianetti seals are available from Mazda Competition parts dept in the States.
There are all sorts of variations available,
eg 2 mm,3mm,and either 1 piece or 2 piece.
I talked to Mr Ianetti the other day and he said that they could make them in 4mm or 5/6mm too.
The price for these seals is minimum of just over £1000.
What is their value you may ask?
2mm will handle about18 to 20 psi boost but can still break with very bad detonation. you must have an after market ECU to be able to prevent high boost engines from detonating.
3mm are able to handle up to 23psi boost and could still break with excessive detonation.
mr Ianetti said that if you had 5 or 6 mm seals then they would be just about indistructable.
Any of these seals in my opinion would be the best for a high boost engine because they have other good characteristics.
eg they are very light( as light as carbon seals) which could mean that if you do the other necessary mods to an engine then more revs are available,low wear on rotor housings.they are reuseable on rebuilds,the seals do not wear out to quick.And the tolerances
can be closer due to low thermal expansion.
hope that this is helpful
Carl
Can the rotor housings be opened up to 5-6mm like you do to make 3mm fit. If so this will be my next re-build.
The Ianetti seals are available from Mazda Competition parts dept in the States.
There are all sorts of variations available,
eg 2 mm,3mm,and either 1 piece or 2 piece.
I talked to Mr Ianetti the other day and he said that they could make them in 4mm or 5/6mm too.
The price for these seals is minimum of just over £1000.
What is their value you may ask?
2mm will handle about18 to 20 psi boost but can still break with very bad detonation. you must have an after market ECU to be able to prevent high boost engines from detonating.
3mm are able to handle up to 23psi boost and could still break with excessive detonation.
mr Ianetti said that if you had 5 or 6 mm seals then they would be just about indistructable.
Any of these seals in my opinion would be the best for a high boost engine because they have other good characteristics.
eg they are very light( as light as carbon seals) which could mean that if you do the other necessary mods to an engine then more revs are available,low wear on rotor housings.they are reuseable on rebuilds,the seals do not wear out to quick.And the tolerances
can be closer due to low thermal expansion.
hope that this is helpful
Carl
Can the rotor housings be opened up to 5-6mm like you do to make 3mm fit. If so this will be my next re-build.
01-11-07, 09:18 PM
#43
I wish I was driving!
Originally Posted by rx7vadim
I Guess No1 On The Forum Know What Exacly Type(s) Of Ceramic Hey R Made Of Exept Glassman
01-11-07, 10:52 PM
#45
