sloted rotors

[Oldblueaccord]

I misunderstood.
So obviously HSS cut it fine for you, even with the slots.

yes


althought i use carbide on everything.



Hope this makes it to page 5.


wp

[Ichiban]

Nice. Really nice.

You are so fucked up in your comprehension of the material you are posting, you are making it say whatever you want it to.

I would explain how tempering martensite and bainite will eventually change the grain structure back to cementite and ferrite, thus softening the material, but you just can't wrap your head around it. That's right, heating metal composed of martensite or bainite structures will SOFTEN it. Tempering. You won't get it.

YOU CAN MAKE CEMENTITE! YAY!

Wait a second, you were right. Tempering Martensite will cause Pearlite (cementite and ferrite) to form. Even your graph says so. Unfortunately Martensite is the hardened phase of iron or steel, and your brake rotors would never be made this way. Why? Because every time you use them, they would temper themselves back to a Cementite/ferrite structure.

That's right, heat will make them become softer. Even after they cool. That is what tempering is. But you'll argue this, I only learned it in school and practiced it, but you read an article.

Your own chart states that martensite begins to temper back at 150 C, no brake manufacturer would make rotors that change phase at that temperature.

I just thought of something: Maybe brake rotors have been mildly heat treated, and Cementite is still to blame. Localized heat causes tempering of the iron back to the cementite/ferrite mix from the possible previous martensite bainite structure and makes a soft spot. That would be more plausible, given my knowledge on the subject. Oh, and the tempering chart you posted, even it agrees with me. But even this doesn't make sense because after 1 or 2 hard brake applications the heat treating would be tempered out anyways.

Basically (and everything you've posted supports this with exception of Carrol Smith)

Iron + Carbon= Cementite and ferrite, add heat, it becomes austenite (everything is dissolved) cool slowly, goes back to cementite and ferrite
Quench quickly, cementite is trapped in iron matrix, forms martensite, slowly heat martensite, tempers back to cementite and ferrite.

This is all material I was tested on in school. It is FACT.

If you mix molten Iron and Carbon and let it cool, you will get Cementite and Ferrite.

Silicon is added to PROMOTE formation of graphite, and AVOID the formation of cementite. Read it properly.

Also, saying that silicon containing brake pads will cause cementite to form is plain wrong. You are making this up. Cementite=Fe3C. There is no silicon involved. Look up the term "undercooling" and it will all make sense.

I've long studied the change in a metal's properties with heat. It's called tempering, and it's tendency is to make metal softer, not harder.

Since your theory still goes ass backwards to years of study and school, you're still wrong. Once you have the education to properly interpret what you are using for examples you will understand this.

[2ndGenGuy]

I CLEARLY stated in the first example that crappy pads with a LOW max operating temp are more likely to cause uneven pad deposits, because they require a much lower temperature to transfer pad material. Instead of reading this correctly, you read the opposite.

Editing out your condescending, insulting remarks, I will reply to this. High temperature pads prevent heat transfer to the brake fluid and other components and prevent glazing. There is nothing about high temp pads that claim to cause less material transfer. Where you came up with this, might make sense since they have a higher operating temperature, but I've sure as hell never heard this claim or heard it as reason people use high-temp pads. People get material transfer from high-temp pads all the time. High operating temp does NOT mean material transfer doesn't happen at lower temps.

Not only this, but the temps required for cementite to form, according to you, are WELL WITHIN the range of high temp pads. If it can form with cheap pads, which cause braking issues at lower temperatures, and generally will cause no further heat, then it sure as shit can form with high-temp pads as well.

I reformed that statement with the word "expensive" instead of "cheap" to show you how the effects are EXACTLY the same, and how that example of the process you keep using has NO LOGICAL BEARING on whether you use cheap materials or expensive materials.

Quit being insulting and saying how nobody understands you. We read what you're saying, and again, you avoided EVERY SINGLE POINT I made in my post. If you can't argue without being condescending, quit arguing. Quit making this into a personal thing to try and make yourself look good.


And one more point out of the realm of what I know:

Alloying additions such as Si or Al are made to suppress cementite precipitation...

http://www.scielo.br/scielo.php?pid=...pt=sci_arttext

The silicon retards the growth of cementite...

www.springerlink.com/index/L083011067N6J038.pdf

Silicon promotes ferrite formation and retards the formation of cementite.

http://www.steeluniversity.org/conte...eid=2081271601

...silicon (retarding the cementite formation and thus. increasing the stability of austenite...

http://72.14.253.104/search?q=cache:...ient=firefox-a

Silicon is known to inhibit cementite formation in steels

http://etd.library.pitt.edu/ETD/avai...PhD_Thesis.pdf

I don't think I have to say anything more.

[Oldblueaccord]

I just read a little about what was written on Carrol's site as well as stop tech. I think the point not mentioned is what was written in his book was copywirtten in 1975. What was known then about casting/ metals /race cars cams motors is old news. Its 2007 almost every thing has changed as far as cars has changed. Good read over all but I consider it ancient history.

Stop tech does not sell cheap rotor.


http://www.stoptech.com/products/rotors.shtml


Mark Donohue "Unfair advantage" is one of my favorite books from that era. Read it. Its a boiagraphy but it filled with technical aspecs of all the cars he drove. In fact the chapters are broken down buy what car he drove.

http://en.wikipedia.org/wiki/Mark_Donohue

You will be amazed at what they did not understand about aerodynamincs and how they work even in the early 70's even after they had sent a man to the moon.

wp

[MessyHonda]

......screw brakes....im stoping with magnatic fields now....lol

[2oodoor]

[HostileJava]

......screw brakes....im stoping with magnatic fields now....lol

Yeah but how are you stopping?

[guaynabo89]

ok how about this.............


At what temperature does cenemtite form? (im not reading al the links)

Do brake rotors really reach that temperature? I mean Kelvin explained that at high speed rotation the area where the cementite formed kept geting hotter as it spun by the pad ie highway. BUT at highway speeds there is so much cool airflow that would keep the rotor from heaing up to drastic temperatures.

[2ndGenGuy]

ok how about this.............
At what temperature does cenemtite form? (im not reading al the links)
Do brake rotors really reach that temperature? I mean Kelvin explained that at high speed rotation the area where the cementite formed kept geting hotter as it spun by the pad ie highway. BUT at highway speeds there is so much cool airflow that would keep the rotor from heaing up to drastic temperatures.

When the temperature of an alloy reaches 1333 ºF (733ºC), austenite transforms to pearlite (fine ferrite-cementite structure...

Source: http://www.substech.com/dokuwiki/dok..._phase_diagram

Temperatures between the pad and disc do not normally exceed 700°F even in heavy street use. In race use 900-1200°F is common on smaller cars and in Championship Cup race temps. shoot up to around 1500°F where discs will glow red or orange.
ALWAYS CHOOSE A PAD ADEQUATE FOR YOUR NEEDS. NEVER just choose a race compound because you think you’re a hot shot. Many/most race pads need “warm up” and don’t become effective till 350°F.

Source: http://www.ebcbrakes.com/QandA.html

And if it were true that your pads heated up from just driving, and no brake pedal pressure, to temperatures like that, then your pads would be constantly glazed and completely ineffective. They would smell, and smoke and be just plain awful.

Here's some news: yours pads are ALWAYS in contact with your rotors ever so slightly. There's just not enough pressure to heat them up to where they get that hot. If it were true that areas that contact the pad got that hot, they'd ALWAYS be smelling and glazing and they wouldn't work at all. Your brake fluid would be boiling... ugh none of that stuff makes sense at a basic or scientific level.

I'm sure most of us have driven cars that have REALLY BAD pulsation in the brakes. Do they heat up that hot when you're moving down the freeway? No, the raised areas on the rotors DON'T GET THAT HOT. Again, if they did, they would be smelling, smoking, etc.

[Ls1-Inside]

You are completely hopeless. You can't even read correctly. That is the problem here. I CLEARLY stated in the first example that crappy pads with a LOW max operating temp are more likely to cause uneven pad deposits, because they require a much lower temperature to transfer pad material. Instead of reading this correctly, you read the opposite. You read 'expensive' instead of crappy. How? Who knows. All I know is that I'm done with you.
I give up on you. The brake lord has banished you from the land of the intelligent. He could respond to your other posts, but you've made it quite clear you're unable to understand simple paragraphs and examples correctly. I'm not sure if it's your brain, or your reading ability, but something 'just ain't right' in your comprehension abilities.
PS: I've had extremely aggressive pads on my car for 40,000 miles. Have not needed to replace a rotor or the pads yet. Have not had any pedal pulsation. At all. Always smooth. Always works great.

Wow if you're going to be a completely immature, rude, noob and not address 2ndGenGuy atleast address me.
Please - to make things more clear, if you will, list your points and the facts that you're trying to get across, bulletined so you can clearly defend them, and speak to each point.

As I see it you're saying:

1) Rotors Never EVER WARP

2) Silicon actually HELPS cementite form

3) Brake Shudder is ALWAYS from Unevenly deposited material

4) Unevenly deposited pad material can NEVER be repositioned during bed-in, and your rotors will quickly turn to cementite and shudder...

5) Your Rotors/Pads exceed temperatures required to form cementite during normal daily driving (1000F+ )

6) High Operating Temperature pads will not deposit Pad Material to the rotors. And are adequate for daily driving...

7) Carol Smith is super duper famous, and is an expert in the metallurgy and brake rotor technology field who can not be refuted by modern science.

8) High Temp Pads will somehow PREVENT unevenly deposited pad material

I'm sure you're making other points here... and they all look very valid... Feel free to include these as well as all of your other pearls of wisdom in your list...

Or you could always choose to disregard all the points any poster makes, repeatedly link a 30+ year old opinion paper w/ no scientific studies behind it, and, oh my personal favorite, - bannish posters from "the land of the intelligent" in a child like defense.


Dan

[guaynabo89]

thats the point im trying to make.

I dont beleive daily driving will heat brakes enough to cause cermentite to form, some cases maybe, racing or heavy use probably. iron can warp just like any other metal. Saying it wont is like saying water wont urn to ice if I freeze it.

[2ndGenGuy]

Carol Smith is super duper famous, and is an expert in the metallurgy and brake rotor technology field who can not be refuted by modern science.

[Ichiban]

This is all getting rather hilarious, I'm glad it's not just me on this side of the discussion. I thought I'd rehash a few basic heat treating principles for clarity: The pictures and graphs both Kelvin and myself have posted give a visual representation of what I'm about to say.

Iron and Carbon in solid solution: Above 930 C Carbon dissolves completely in Iron. This mixture is homogenous, and consistent throughout. It is non-magnetic and slightly denser than the equal mass of solidified mixture. This material is termed Austenite and is capable of plastic deformation. Forging is carried out at this temperature range.

Pearlite Formation: If Austenite is allowed to cool naturally, several things can happen depending on carbon content. If the content is below 0.83 percent, Pearlite will form interspersed with grains of ferrite, pure iron. This steel is typically non hardenable. One can quench it from austenite and achieve little or no hardness gain. If the Austenite contains more than .83 percent carbon, it will cool to form Pearlite grains interspersed with Cementite (iron carbide) which forms outside the pearlite grains due to it having nowhere else to go. If the Austenite solution contains more than 1.7 percent carbon, then Pearlite, Cementite and grains of Graphite are now formed. Why? The capacity of the solid Iron to absorb carbon at 1.7 percent is exceeded, and the excess carbon forms grains of graphite, which is pure carbon. Solid material with more than 1.7 percent carbon is considered cast iron.
Pearlite is soft, ductile, tough and easily machinable grain structure.

Martensite: If austenite with a high carbon content is quenched in water or oil, the rapidly forming Cementite and Ferrite grains don't have time to seperate out fully. Instead a needle like structure of martensite forms. It is very fine grained, and is characterized by exceptional hardness and brittleness. High carbon steels are hardened by this method (drill bits, chisels, etc.) The Cementite and ferrite are still there, they are just dispersed in very fine grains instead of the pearlite formation due to the rapid cooling.

For the purpose of this discussion I will avoid the topic of air hardening alloys, which do not require quenching to harden, only normal cooling. As these steels are alloys and we are dealing with generally plain carbon items, it really isn't important.

Tempering and Drawing: As Martensite is usually way to hard and brittle to be of much use, one must take some of the hardness and brittleness away and induce some other desireable traits, like toughness and some ductility. You can do this by reheating the martensite item slowly to a specified temperature, usually a tempering oxidation color chart. You know how steel turns tan, then brown, blue and black as you heat it? Well, we actually use those oxidation colors to tell what degree we have heated the item to during tempering. Too cold, and the material will fracture under use. Too hot, and the hardness will be lost, and the item will wear rapidly, as the martensite has been changed back to cementite and ferrite (pearlite) which is the softer phase, remember?

Suppose you wish to machine an item of hardened material? You can use a process called a spheroidizing anneal to put all the martensite back to pearlite. Sound complicated? Not really, you heat the material back up to pure austenite, then cool it slowly over a period of hours to reform the pearlite grains, (ferrite and cementite) which machine easily due to their large round shape, hence the spheroidizing anneal.

Case hardening: If a mild steel item needs to have the abrasion resistance of a hard alloy, or needs to retain a ductile tough inner core, you can case harden it. Basically, the part is soaked in a carbon rich solution for a period of time, and the outer surfaces absorb the carbon and become hardenable. Case hardening usually affects only .010 to .050 below the surface of the part.

Summary: While it's true that the presence of cementite determines the hardenability of iron or steel, its infact the particular grain structure of the material that affects hardness. Due to its high carbon content, cast iron is typically hard and brittle, making it ideal for wear surfaces but not for structural parts. Cementite will form in two ways: Slow cooling from austenite, or tempering Martensite.

Either way, the presence of cementite indicates a softer, ductile grain structure and not the harder wear resistant "patch" used to explain uneven rotor wear. The slow heating/cooling cycles of a brake rotor will tend to anneal the material, rather than harden it.


References:

1. Machinery's Handbook, 27th edition.

2. Trac Trades/Common core Line F Metallurgy and heat treating.

3. ITAC Machinist/Millwright Line ? Heat treat steel

4. Technology of Machine Tools, 6th Edition.


I will add/sort more references tonight.

[Kelvin]

More articles from BRAKE ROTOR COMPANIES that claim rotors never warp:
http://www.raceshopper.com/tech.shtml#warped_rotors
"Warped rotors (in most instances) are caused by the brake pads being operated at temperatures outside of their specified range. When the pads get too hot the pad material actually melts and 'fuses' itself to the rotor surface and creates a 'bump' on the surface of the rotor. In most cases this is not noticeable to the naked eye. This creates an annoying vibration when the brakes are applied"
This is exactly what I said above. Shitty pads with a low maximum temperature= uneven pad deposits. Yet still, certain people argue and claim that high temperature pads will work exactly the same as shitty organic pads. Why? Who knows. Some people buy tornado fuel savers.
Here's another BRAKE MANUFACTURER that claims that rotors never warp, and I'm guessing they know more about rotors than certain so called 'experts' on this forum.
http://www.performanceoiltechnology....ingsystems.htm
"The problem with this diagnosis and repair procedure is that first of all is that brake rotors do not warp. The second problem is that replacing a brake rotor with a new brake rotor or machining the rotor on a bench lathe will only fix the problem temporary. The problem will almost always re-occur after a period of time, thus necessitating further repairs. Brake rotor disc thickness variation or excessive lateral runout, as well as drums that are out of round can cause vibrations and pulsations in the brake pedal and/or steering wheel. Brake lining material transfer onto the rotor can also have an effect on this as well. "
But go ahead. Keep arguing. You guys are obviously more experienced and more knowledgeable than brake companies, or Carroll Smith.

[Kelvin]

[QUOTE=Oldblueaccord]I just read a little about what was written on Carrol's site as well as stop tech. I think the point not mentioned is what was written in his book was copywirtten in 1975. [quote]

So what? Disc brakes back then haven't really changed much in today's cars, PLUS we're talking about 1986-89 hondas. If we were talking about porsche's with ceramic rotors, you'd have a point. If anything, the brake technology he was working with in the 1960s, 70s, and 80s is more advanced than the puny, simple brakes on our hondas, so your point doesn't really make sense at all. Also, I suggest reading all of it, but I doubt you will.

What was known then about casting/ metals /race cars cams motors is old news. Its 2007 almost every thing has changed as far as cars has changed.

Are you inferring that the average car uses rotors and calipers completley different from what was availabe in the 80s? How do you think casting 'cast iron rotors' has changed? I don't buy your 'hypothesis' here.

Stop tech does not sell cheap rotor.

For the 50th motherfucking time, THIS ARTICLE WAS NOT WRITTEN ABOUT STOPTECH PRODUCTS. It was written about brake rotors, applicable to all disc brakes that use cast iron rotors.

[HostileJava]

Well I'm not saying your wrong, but if I was a brake rotor company I'd publish articles saying that brake shudder is the fault of the driver and/or pads and not the fault of the rotor.

[Kelvin]

ok how about this.............
At what temperature does cenemtite form? (im not reading al the links)
Do brake rotors really reach that temperature? I mean Kelvin explained that at high speed rotation the area where the cementite formed kept geting hotter as it spun by the pad ie highway. BUT at highway speeds there is so much cool airflow that would keep the rotor from heaing up to drastic temperatures.

They can if they have uneven pad deposits, as the 'high spots' of pad material will lightly scrape your pad with every revolution, gradually building more and more heat. Your rotors will not be 'glowing orange', but small, localized areas will be heating up MUCH more than everything else. Don't believe me? Rent on of those IR thermometers, and shoot it at different parts of your rotor. They'll read different temperatures. Now imagine a high spot that hits your pads more than eveyrhting else else does. It will be the hottest.

Well I'm not saying your wrong, but if I was a brake rotor company I'd publish articles saying that brake shudder is the fault of the driver and/or pads and not the fault of the rotor.

That IS what they are saying. They said it is the result of OVERHEATED PADS RESULTING IN UNEVEN PAD DEPOSITS RESULTING IN LATERAL RUNOUT WHICH CAN RESULT IN CEMENTITE.
Fucking christ. I give up on this thread.

PS: Santa is real too! I have many witnesses who can claim to it! They will provide personal experiences of waking up, and having presents magically delivered under their tree! They KNOW he is real, and have seen evidence! Even the cookies were eaten!

I'm guessing the people who belive in warped rotors are the same people who believe that god controls everything, like the wizard of oz.

[HostileJava]

That IS what they are saying. They said it is the result of OVERHEATED PADS RESULTING IN UNEVEN PAD DEPOSITS RESULTING IN LATERAL RUNOUT WHICH CAN RESULT IN CEMENTITE.
Fucking christ. I give up on this thread.

No, actually it's not. I'm saying if I was a rotor company I'd publish articles that looked favorable. Those favorable articles may indeed be correct, but that's not for me to judge. That's all I said, I did not in fact say anything stating you were wrong or right. And stop double posting.

Edit: I reread your post and I think you misunderstood my post. My point being there not going to publish somthing that makes there product look bad. Comprende?

[Ls1-Inside]

PS: Santa is real too! I have many witnesses who can claim to it! They will provide personal experiences of waking up, and having presents magically delivered under their tree! They KNOW he is real, and have seen evidence! Even the cookies were eaten!
I'm guessing the people who belive in warped rotors are the same people who believe that god controls everything, like the wizard of oz.

are you talking about?
This is the 2nd time you've posted a completely childish answer and it speaks worlds about your credibility.

"(In most cases)" does not mean ALWAYS. Figure that out!

You're cracking me up Kelvin

I can't stand replying to your posts any more. They're obnoxious, annoying, incorrect, repetitive of useless/misguided information, and frankly wrong.

You're taking accurate information out of context and trying to apply it to everything while manipulating it to make it say what you want and completely misinterpreting it. Then you're switching what you're talking about left and right: At first it's All Brakes (race cars or daily drivers) then it's Race cars only, now we're just talking about 80's Honda's? Which one is it? You don't know. You're answers don't apply to everything. Your absolutes are absolutely incorrect. And you're arrogance and stubbornness is wildly disturbing.
You won't accept simple physics, you take a "In Most cases" to mean "ALL THE TIME" and preach it, you attack members, and lace every reply deeply with sarcasm, you repeatedly post multiple replies instead of using the "Edit/Modify" functionality, you refuse to address simple questions with direct answers, you cloud up your answers and continuously use typical Internet-Troll tactics, i can go on about all the things wrong with just you alone. And all of that i can determine without even addressing all the things you're wrong about regarding brakes.

If this is offensive it's meant to be, if you're done with this thread I say 3Geez is better for it. If you never post another thread in here again this community will continue to grow, learn, remain open minded to new discoveries, and accept the facts of life as a healthy community of car enthusiasts should.

I would recommend you find another forum to preach to, and find some underlings and subordinates that will tolerate your childish mannerisms and worship you as the god you seem to think you are. I'm currently looking for the ignore functionality in the forum so i don't have to suffer the agony of reading another post from you.

Continue doing yourself a disservice by posting and spreading your inaccurate interpretations of automotive engineering and you'll only prove to me how obviously stubborn and confused you really are.

-Dan

[Oldblueaccord]

"This message is hidden because Kelvin is on your ignore list"



You can just add him to your ignore list its under prefences


wp

[Ichiban]

You are the one claiming santa, not us. I warped metal today with an oxy-fuel cutting torch. And my training and knowledge is the same of everyone else who works metal for a living, the people who make brake parts are part of that everyone else. Brake parts must conform to the same basic principles of the material they are made from.

At school we have carried out labs to test and check for every material condition I've spoken about. We heat different steels, cool them, cut them, wash them with an acid solution and then LOOK at the resulting formations. I have MADE and SEEN cementite, martensite, bainite, pearlite etc. With my own eyes and a torch, and some basic instructions. I was trained to UNDERSTAND these features because they are pivotal to a career in machining. I have to be able to form, change, modify and understand all of these phases of metal intimately.

Then you come along claiming "cementite" in a matter that is totally out of context to what I know to be true. You claim "cementite magically appears" in a manner that is actually contrary to it's true behavior, no reasons, it just is. While my knowledge is based on processes, change and development within the material, yours is an arbitrary "Carrol Smith said it, it must be true".

I'm amazed that not only would you call my knowledge and training into question, but you'd insult me and my ability to excel at my career. I hope you find Santa.

[Kelvin]

Sure thing Bill Nye. You obviously know more than Carroll Smith, and brake companies. I forgot.

[Ls1-Inside]

"This message is hidden because Kelvin is on your ignore list"
You can just add him to your ignore list its under prefences
wp

Thanks - He's been added.


Dan

[Oldblueaccord]

No, actually it's not. I'm saying if I was a rotor company I'd publish articles that looked favorable. Those favorable articles may indeed be correct, but that's not for me to judge. That's all I said, I did not in fact say anything stating you were wrong or right. And stop double posting.

Edit: I reread your post and I think you misunderstood my post. My point being there not going to publish somthing that makes there product look bad. Comprende?

Thats what I thought when I posted that stop tech sells rotors and they aint cheap at least by my standards.


I like Stop tech but he hurt himself in my eyes by directly contradicting what he writes in that brake test in Sport compact car. He writes about bedding in brakes correctly and list his ways but in the article his set up was not working so he "rebed them in quickly by heating the brakes until they smoked" thats a paraphrase by me. He did that in one pass.

Basically he thru out everything he had written on his website and did it the way everyone else does. And of course his brake kit still didn't stop in a shorter distance then a stock good pad/rotor setup does after 10 repeated trys.


wp

[Ichiban]

Sure thing Bill Nye. You obviously know more than Carroll Smith, and brake companies. I forgot.

Education or advertising, I see you've made your choice. I've made mine.