Plasma, cement, ceramic coatings. First Impressions
07-08-05 | 12:46 AM
#126
Thread Starter
Rotary Freak
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Joined: Apr 2001
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From: alberta, canada
Originally Posted by t-von
Wow very good post (makes a lot of since) however, there are some things that Mazda could have done better at the cost of longer term reliability.
Off topic example: The 13b engine found in the GSL-SE is still the more bulletproof NA engine Mazda has ever built. Why? This engine has the factory 3mm 2 piece apex seals that really don't wear out. You compare that to Mazda's useless experiment to run 3 piece 2mm seals in the later 13b's. Why, because these seals are suppose to seal better. Well they do but at the cost of long term reliability. The top seal piece will wear down over time and become very brittle with age. A thin brittle seal will break a lot easier than a thick brittle seal. It's no wonder the NA 13b engines found in the 2nd gen don't last as long.
Anyways it's funny how Mazda went back to the more durable/longer lasting 2 piece design.
Now back on topic.
Off topic example: The 13b engine found in the GSL-SE is still the more bulletproof NA engine Mazda has ever built. Why? This engine has the factory 3mm 2 piece apex seals that really don't wear out. You compare that to Mazda's useless experiment to run 3 piece 2mm seals in the later 13b's. Why, because these seals are suppose to seal better. Well they do but at the cost of long term reliability. The top seal piece will wear down over time and become very brittle with age. A thin brittle seal will break a lot easier than a thick brittle seal. It's no wonder the NA 13b engines found in the 2nd gen don't last as long.
Anyways it's funny how Mazda went back to the more durable/longer lasting 2 piece design.
Now back on topic.
groove after about 200,000km.
the 2 pc seals I agree will last much longer but spring pressure once they
wear to the point where the 3pc would flip out will still demand a rebuild,
there will just be less destruction.
matt
07-08-05 | 01:31 PM
#127
Former Rx7 *****
Joined: Nov 2001
Posts: 4,534
Likes: 0
From: Mississauga
Originally Posted by t-von
Wow very good post (makes a lot of since) however, there are some things that Mazda could have done better at the cost of longer term reliability.
Off topic example: The 13b engine found in the GSL-SE is still the more bulletproof NA engine Mazda has ever built. Why? This engine has the factory 3mm 2 piece apex seals that really don't wear out. You compare that to Mazda's useless experiment to run 3 piece 2mm seals in the later 13b's. Why, because these seals are suppose to seal better. Well they do but at the cost of long term reliability. The top seal piece will wear down over time and become very brittle with age. A thin brittle seal will break a lot easier than a thick brittle seal. It's no wonder the NA 13b engines found in the 2nd gen don't last as long.
Anyways it's funny how Mazda went back to the more durable/longer lasting 2 piece design.
Now back on topic.
Off topic example: The 13b engine found in the GSL-SE is still the more bulletproof NA engine Mazda has ever built. Why? This engine has the factory 3mm 2 piece apex seals that really don't wear out. You compare that to Mazda's useless experiment to run 3 piece 2mm seals in the later 13b's. Why, because these seals are suppose to seal better. Well they do but at the cost of long term reliability. The top seal piece will wear down over time and become very brittle with age. A thin brittle seal will break a lot easier than a thick brittle seal. It's no wonder the NA 13b engines found in the 2nd gen don't last as long.
Anyways it's funny how Mazda went back to the more durable/longer lasting 2 piece design.
Now back on topic.
I've seen many rotary engines pass 300,000 kms or 400,000 kms all stock and no problems with engine.
07-08-05 | 08:51 PM
#128
Originally Posted by Cheers!
I think everyone needs to step back for a moment and look at their car. If you modded your car you should not say anything mazda this and mazda that about bad reliability.
I've seen many rotary engines pass 300,000 kms or 400,000 kms all stock and no problems with engine.
I've seen many rotary engines pass 300,000 kms or 400,000 kms all stock and no problems with engine.
Maintenance was spot on. My Fd is also stock with 95k original miles. It has been more reliable than my Fc however, I feel the 3 piece seals are close to their end. Thats why I'll rebuild the engine before they let go and cause more damage. The flipping out problem wouldn't be a problem if Mazda had stayed with the original 2 piece design.
07-08-05 | 09:12 PM
#129
Thread Starter
Rotary Freak
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Joined: Apr 2001
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From: alberta, canada
my vert n/a motor had 188000km on it when i pulled it out and i am sure
the seals would have flipped out of the rotor groove within another 10 to 15,000km
200,000 is doing really good on a 3pc. seal
going farther just = rotor groove wear
and housing damage.
matt
the seals would have flipped out of the rotor groove within another 10 to 15,000km
200,000 is doing really good on a 3pc. seal
going farther just = rotor groove wear
and housing damage.
matt
07-09-05 | 01:12 PM
#130
boxed in and drawn out
Joined: Dec 2003
Posts: 555
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From: Bayouself
Originally Posted by couturemarc
Know your history! Toyo Kogyo: aka Mazda used these types of coatings in R & D in the late 60's and early 70's, cermet type coatings were initially developped to solve the wear and durability problems (chatter) in rotary engines because the chrome technology of the day was not advanced enough to provide the proper characteristics for a rotary.
The end result (back in the 70's) was that the cermets were too expensive and lasted too long and also had not been tested and developped to the same extent as chrome. As the engineers on this forum will testify, automakes design parts for a certain life cylce, they are intended to fail and be replaced after a certain "pre-determined" life. A part that last too long does not make the company money, bottom line.
On top of all this, there was initially (and possible still) only one plant that plated and finished rotor housings. This means one large capital investement in only one coating method and they have stuck with that choice and furhter developped it over the years.
There is no advantage for Mazda to offer a longer lasting part to the public at a higher internal cost to them, nevermind the huge investment to set up a second coating process.... especially considering the relative low production numbers.
When it comes to racing, durability and wanting nothing but the best Mazda chose to put cermet coatings in the R26B LeMans winning racecar. So, its not that Mazda cannot do this... they just have absolutly no reason to want to unless they need a competitive edge.
As for us, our goal was to offer a refurbishing service using this high end racing technology at a COST EFFECTIVE price that most builder can afford. Take it or leave it just do your homework before making claims such as mazda not being able to do this.
The end result (back in the 70's) was that the cermets were too expensive and lasted too long and also had not been tested and developped to the same extent as chrome. As the engineers on this forum will testify, automakes design parts for a certain life cylce, they are intended to fail and be replaced after a certain "pre-determined" life. A part that last too long does not make the company money, bottom line.
On top of all this, there was initially (and possible still) only one plant that plated and finished rotor housings. This means one large capital investement in only one coating method and they have stuck with that choice and furhter developped it over the years.
There is no advantage for Mazda to offer a longer lasting part to the public at a higher internal cost to them, nevermind the huge investment to set up a second coating process.... especially considering the relative low production numbers.
When it comes to racing, durability and wanting nothing but the best Mazda chose to put cermet coatings in the R26B LeMans winning racecar. So, its not that Mazda cannot do this... they just have absolutly no reason to want to unless they need a competitive edge.
As for us, our goal was to offer a refurbishing service using this high end racing technology at a COST EFFECTIVE price that most builder can afford. Take it or leave it just do your homework before making claims such as mazda not being able to do this.
I assume your R&D for this specific application is the same or more refined and is something the motorcorporation could not develope. But yet they were spraying alloy treatment for mass production.I would like to know because I am a laymen, how your steps and application differ while it is more cost effective and in doing so providing the technology you stated makes the housing last so long that Mazda wouldnt use it.
Can it be assumeed you apply your coating to the steel surface which has no alloy substrate left after machining because of the inherent long term bonding issues as stated in reference articles.
If you are able to provide the maixum usage and savings I support your efforts and thinks it wonderful.I am a rotor enthusist and love the info.I just read where guys are getting housing back with grooves and suface applications which were too thick and had to be addressed again.
Here is some history that maybe others can inform themselves.
The 10A series was Mazda's first production Wankel, appearing in 1965.
The rotor housing was made of sand-cast aluminum plated with chrome, while the aluminum sides were sprayed with molten carbon steel for strength. The addition of aluminum/carbon apex seals addressed the chatter mark problem.
The final member of the 10A family was the 1971
The new Transplant Coating Process (TCP) featured sprayed-on steel which is then coated with chrome.
In 1974, a new process was used to harden the rotor housing. The Sheet-metal Insert Process (SIP) used a sheet of steel much like a conventional piston engine cylinder liner with a chrome plated surface. The side housing coating was also changed to eliminate the troublesome sprayed metal. The new "REST" process created such a strong housing, the old carbon seals could be abandoned in favor of conventional cast iron.
Rotary Engine
Page 22 sect 3.9
…for aluminum alloy housing, its inner surface over which the apex seal slides has been chrome plated for higher wear resistance.To improve the adhesive property of chrome plating, a new manufacturing method called SIP (Sheet- metal Insert Process), has been developed.
In this method, a sheet of steel is formed to the trochoid surface is inserted inside the rotor housing and its inner surface is chrome plated.
Section 3.10 Inner Surface Treatment of Housing
In early development….
As a result, it proved effective to use hard chrome plating containing silicone carbide particle (Nickasil, Elnisil) spraying of combined carbide or molybdenum alloy etc.
The hard chromed surface is usually performed over a steel sheet layer in the SIP method, as above mentioned,( since direct chrome plating on aluminum," alloy results in poor adhesive property and strength.
09-07-05 | 01:48 PM
#135
Senior Member
Joined: Jun 2002
Posts: 524
Likes: 0
From: Louisiana
Jebus! I just read this whole thread and I think it is kinda sad that you havent recieved your housings back yet.. I know you said you weren't in a rush but come on? How many times have you sent them back? You only stated sending them back 1 time, but was wondering if there were other problems to cause such delays? I wait anxiously to see what specs they have when they come back. The principle behind this seems really nice, and I would personally love to try it out if I hear more positive turn outs.
Dane
Dane
09-07-05 | 02:22 PM
#136
What I don't understand is how I received my housings after Now had sent his back in. I also know of another member that received his housings about a month ago. But coincidentally both of us received housings other than the ones that were sent in.
10-22-05 | 03:27 PM
#139
Originally Posted by rotarypower101
07-07-05, 07:19 PM
Anxiously awaiting a review.
I would hope they are head and shoulders above the ones you received previously.
Take good pics and measurments.
10-23-05 | 05:39 PM
#140
Still no conclusive facts... Well, I guess I will keep waiting to hear the outcome on this.. I have about 20 pairs of housings that I have been keeping in hopes of sending them to JHB. I know Mazda will eventually NLA the S5 Turbo II housings like theu have already NLAed the S4 Turbo II Type and the FC guys will either upgrade to FD type or have to get good low mileage USed housing or have thier housing Rebuilt thru JHB.. I guess time will tell if their service works..
