Tom Johnson

Mid America sells cryogenically-treated brake rotors. They claim they increase brake life by 250-400% and reduce brake pad fading. What are your thoughts on these front brake rotors.

81vette

Not sure about the Mid America rotors, but Van Steel has the cryo rotors with machined slots to reduce gas build-up between the pads and rotor. Van Steel also has good pricing. I doubt the cyro process reduces fading, but it does provide for a longer life and is probably not as susceptible to warpage. The slots will reduce fading by removing the gas, and they provide a slight increase to the rotors surface area for cooling.

Mark


[Modified by 81vette, 12:38 PM 10/6/2003]

Smokehouse69

I saw something about cryo treating of metal objects a couple of years ago on TV. From what I can remember it had to do with magnetic alignment of the molecules in the object. For example if you placed a knife blade in the liquid nitrogen for 24 hrs (? I can't remember the exact time) and aligned the blade with magnetic north, then some how all the magnetic charges of the molecules would line up perfectly and you'll end up with a much stronger knife, that holds an edge much longer than normal.
They were taking disposable razors and cryo-treating them and the guys claimed they stayed sharp for months.
Supposedly all sorts of metal objects could be treated for much longer life, cam shafts, crank shafts, pistons, rods even whole engine blocks could be treated and supposedly end up many times more durable than the untreated metal.
This is what they claimed, I have no personal experience with cryo-treating, but remembered at the time that it might be a good business to run out of a garage. They were using old chest type deep freezers and home made coolers to do the treating in.

PS I found this website of a place that does the treatment. http://www.cryometals.com/about.html They don't mention anything at all about magnetic alignment, but do say that it as a result of molecular movement at the atomic level that results in the "release of internal residual stresses. " They do mention treating brake rotors!




[Modified by Smokehouse69, 1:20 PM 10/6/2003]

Robert N

Taken from http://www.diversifiedcryogenics.com :

Deep cryogenic tempering is a one-time, computer-controlled process where metal is cooled slowly to deep cryogenic temperatures (-300 F), and slowly returned to room temperature. The metal is triple-tempered as the final step in the process. This dry process permanently refines the grain structure....at the atomic level, producing a homogeneously stabilized ... The denser, smoother surface reduces friction, heat and wear.

They have a few neat links. This one is specific:

http://www.frozenrotors.com/

Smokehouse69

BTW, What is Mid American charging for these rotors?

gerry72

Cryo is a well known technology to reduce stress in metal components. It essentially allows the metal to "cure" at the molecular level. An example of where cryo is used: In stock and super stock, the factory rocker arms must be used. In the small and big block Chevy, once spring pressures get up there the force will flex or bend the rocker or the pushrod will punch through the hole. By cryo treating the rockers, stock rockers can live under the astounding spring pressures these engines run without flexing, breaking, or galling.

It is commonly used in the pro racing ranks for blocks, cranks, rods, and pistons as a method of stress relief.

Tom Johnson

Mid America is selling the front rotors for $109.99 each. These are not slotted. VBP sells the front rotors for $135.95 each and the rears for $139.95 each. These are slotted.


[Modified by Tom Johnson, 1:52 PM 10/6/2003]

norvalwilhelm

When a piece of steel is heat treated it is heated to a range where the structure changes to austenite. This austenite is none magnetic and when the sample is quenched to harden it the austenite changes to martensite. A very hard structure full of stress but some of the austenite which only exists at high temperatures gets trapped by the quenching so we have retained austenite at room temperature trapped in martensite. The transform all the austenite to martensite we further quench in liquid nitrogen. All the austenite becomes martensite.
We then put the martinsite into a furnace at lower temperature and releive some of the hardness and brittleness. Books tell you the tempering temperature for an exact hardness.
I haven't a clue how cryogenically treated brake parts are any better, if in fact it is just not a marketing ploy.

Van Steel

How about this. I am about to run a special on slotted rotors which are cryo-ed for $100 each. I can do regular rotors for $85.

They do last longer. I've been told by the guy who does all of out stuff, they last 4-5 times longer. I'm not sure what the 250-400% computes to. When ever you compound molecules together in a metal they will always be stronger. Slotted rotors will help the pads from fading not regular heat treated rotors.

Scooter70

My only comment on cryo'd rotors is this... The C4 & C5 race guys that I hang around with don't use them. Mostly because, for the price, they can buya few sets of stock rotors to have an equal lifespan and they perform just as well. Also, I believe that the cryo process makes the metal more brittle and more apt to crack, especially around holes and slots. If someone's going to give a deal, it might be cool, but I wouldn't expect any gain in braking performance.

Van Steel

Scooter your right about the C4 & some C5 guys. But there brakes are very different from the C3's. Personally I think the C4 calipers are junk. The C3's are a much better design but the C4 calipers are lighter.

Pete79L82

I have never used cryo treated rotors but I do have blocks and cranks cryo treated. Stock blocks have a problem with the main webs cracking when you use them in racing. I find that the cryo treated blocks last much longer berfore they crack. They also hold a much truer cylinder wall which leads to less leakdown between freshenings. I see only a slight power increase when the motors are fresh but the cryo treated blocks don't drop off as much as the non treated blocks. With the cranks the bearing surfaces and the bearing themselves look much better on a treated crank. I am a firm believer in it on motor parts.

MotorHead

I almost bought a cryo crank, then I thought to myself " What am I doing I should know better by now "

Not to take anything away from the brakes but it must be pretty easy to set up a test to see whether something is stronger/better after going through this process than not, I have not seen anything, everyone knows a 4340 crank is better/stronger/last longer than cast crank because test have been done to confirm this

As a test I don't mean some BS comparison like the before and after Abflex commercials where the same guy sucks his gut in a minute later :lol:

jburnett

How about the fact that one of your fellow Forum members (me) owns a cryogenic processing firm that SPECIALIZES in motorsports applications?? I'm not on the C3 Forum very often, usually on the C4 side but Ken Reidy (Enchantment), one of my customers emailed me this thread.

Cryogenic processing of rotors is one of our biggest areas; I've got hardcore auto-crossers and road racers that have witnessed increases in disc life by as much as 500%... We do everything from individual components to complete engines, trannys, diffs, and drivelines. I run a 1990 Vette with the OEM Dana 44 IRS that has been completely treated; it runs 9.90's at over 140 mph with short times in the 1.4-1.5 range. It's a ZF stick car and I leave the line by side-stepping the clutch at 5500-6000 rpm and then hitting the nitrous immediately; we've yet to break a part since the cryo-processing.

My main business is industrial and manufacturing tooling as well as timber industry tooling (particularly chipper knives for paper mills). But my primary focus is motorsports and is the market I cater to the heaviest in advertising and at races.

Anyway, Ken thought I should chime in on this so I did. I'm working on some banner advertising on this board right now and when I do will post pricing; in the meantime you can IM me or email me off board if you have any questions or interest.
-Jeb Burnett
Deep Freeze Cryogenics, LLC http://www.deepfreezecryo.com
(866) 324-2796

norvalwilhelm

jburnett please explain what it does? I am a metalurgist and I haven't a clue as to how it increases the life of a rotor or any other part. As for a test I have the facilities and the ability to cyro anything I want. What test could I preform? We do have a rig for testing rotor life but any test like that would take too long and too much of my time.
It is fine to say this really works but how?

jburnett

Actually, I'm not through yet... A few of you are selling the process short (like the "Cryo-Cranks"- which incidentally may be mine because that's the name I market them under); it does indeed highly increase the durability and wear resistance of most alloys (ferrous and non-ferrous metals and some polymer based materials like nylon and delrin). We use computer controlled processors that eliminate any possibility of thermal stress; the materials are brought down to -250F with nitrogen gas at a rate of one degree per minute. Once stabilized at -250F we introduce the liquid phase of the process, liquid nitrogen is -320F. The material is allowed to "bathe" in this liquid until it boils off to atmosphere which is generally 24-36 hours depending upon the size of the load in the processor. Once the liquid phase has ended we slowly bring the material back up to 32F which takes another 24-36 hours load dependant. From there it is switched to our batch over and low temperature tempered (300F-400F) for four hours. This heating process is critical for the immediate and complete transformation of austenitic grain to martensitic and pearlitic grain... What results is an inline, very dense grain structure that not only imparts tremendous wear resistance but also eliminates residual stresses... That is one component that seems to have been left out in this discussion and it is perhaps one of the most important benefits of the cryogenic process. Whenever you cast, forge, machine, weld, or generally work any type of material you are introducing residual stresses. These stresses can manifest themselves in many ways; unwanted harmonics (vibration), stress risers, stress fracturing, and severe "shattering." The cryogenic process eliminates that completely and acts as a dimensional stabilizer, that's right, clearances stay the same and don't move. Most high end precision instruments (micrometer anvils, gage blocks, 123 blocks, parallels, etc) are cryotreated after final machining to ensure they DO NOT CHANGE. The stress relieving characteristics of the process is paramount to this; residual stresses cause shifts in the material. Engine blocks are a great example of this...Ever heard of "core shift?" That's what happens due to residual stresses and cryogenic processing eliminates it. Cast crankshafts are a very popular item for processing because: 1) They have high amounts of residual stresses which generally lead to fracturing. 2) They aren't heat treated like forged cranks are; they're "work hardened" and therefore are much more susceptible to wear. I process a lot of cast cranks for NHRA Stock Eliminator competitors who through either rule regulations or weight issues choose to use a cast piece over a forged one; we've yet to have one break and some of these things run 8k plus rpm and run high 9's... Flat tappet camshafts, valve springs, valves, seats, guides, con rods, pistons, rings, bearings, just about any internal component that is subjected to any of the types of wear (rolling, impact, abrasive, chemical) can be considerably improved.

I know that as someone in this business I may sound biased...But the facts are almost 40 years old now...That's right, this process was pioneered in the aero-space industry, more specifically by NASA who discovered that some of their components were actually stronger after being subjected to the cold vacuum of space than they were before they left. ASM International (better known as the "Material's Information Society"), the group that standardizes material testing and is instrumental in the heat treating arena has a very large symposium on the process. In fact in their "Heat Treater's Guide" 77 of the 90 listed tool steels are recommended for cryogenic processing for increased strength and durability; among them are common automotive materials graphitic cast iron and chromoly steel (you know like 4340 crankshafts and rods?). What are the downsides of the processing? None really, if it doesn't work you haven't harmed the piece in any way. It's non-destructive to everything but natural rubber products (turns them to DUST). The biggest problem is that it does not show up visibly and many people have a belief that "if I can't see it, it hasn't done anything;" well that's completely false. How about power improvement? We typically see a two to six percent increase in power with a cryogenically treated engine over an untreated one and they tend to be much more consistent to boot. This is due to the stabilization of clearances, cylinders and bearing become ovid when subjected to the punishment of running and create more friction. More friction in addition to scrubbing off energy also creates heat which in turn takes its toll on power production.

I would really like to post an article that appeared in the July/August issue of "Precision Engine" that discusses the cryogenic processing of engines in a very "down to earth" way; if someone would host it for me I'll see if I can scan it and email it. The great thing about this text is that it not only explains the processes effects on components but give a couple of great real-world examples of it working... Anyway, my hands are tired from typing so I'll end it here...
-Jeb Burnett

jburnett

Without going into it to the detail you would probably require (I'm NOT a metallurgist but I work with enough of them to know they easily talk above my head) it basically completes the transformation of austenite to martensite and some pearlite... Think of it this way (my simplistic mind) there are "open grains" and "closed grains" in the material...The open grain is loose knit and weak while the closed grain is dense and very strong...That's what you get after processing. My website explains it much better (like I said, I'm now very tired of typing). As for testing the best would be wear tests (abrasive, rolling, impact, chemical) or microscopic analysis of the grain structures (which incidentally I have). But honestly I wouldn't spend your time doing so as there are already inumerable tests on the subject through a variety of sources...I would suggest ASM International (as a metallurgist no doubt you're VERY familiar with the organization).
-Jeb

Fevre

Look at it this way: If it's good enough for Ted's head...

:jester

Sorry it had to said (typed), interesting discussion though, lot to be learned. :yesnod:


[Modified by Fevre, 9:05 PM 10/6/2003]

MotorHead

The crank I was looking at was out of California. I suppose in 40 years there must be a multitude of independant lab test documentation that compares two identical pieces ( cranks, rods or rotors etc., one cryogenically-treated and the other not ). and the results show the cryogenically-treated piece to have a longer life, stronger, less prone to crack etc. ?

Don't get me wrong here I am trying to bash anything on the contrary if I saw some proof of the claims I would probably buy a crank and rods with this treatment :D


[Modified by MotorHead, 8:55 PM 10/6/2003]

427V8

:iagree:
with most except core shift which a reference t the sand casting mold core not being positioned perfectly in the outer mold. Not something you can fix by tempering anything.

I've also heard that cryo works great except in situations where the treated object get's heated, like brake rotors. Hmmm second hand info tho...