warbird

How do you pick a cryo treater? Good question. Obviously my company is just what you are looking for. (SORRY! ) There is a whole range of cryo treaters out there just as there is a whole range of heat treaters. Some are good, some are ok, some are horrible. By the way, most heat treaters think cryo treating is either cooling a part down to –140 F or dipping it in liquid nitrogen. I saw the results of dipping a crankshaft in liquid nitrogen. It made a real mess of the engine on the dyno. Make sure that the company knows what cryo processing is. It is not –140 F cold treating, it is not dipping a part into liquid nitrogen. It is the slow cooling of the part, followed by holding it at the low temperature for a specified time, (usually 8 to 40 hours) followed by a slow heat up back to room temperature. It may or may not be followed by a tempering cycle. Look for affiliations with known entities like the Cryogenic Society of America which covers all things cryogenic, ASM which is the metallurgists and material scientists professional society. Look for experience. A lot of people will buy a machine and then proclaim themselves experts. A company with metallurgists or engineers on staff is a plus. A company that encourages research into cryo processing is a plus. Trade journal articles written by a company are ok, but research papers for serious journals are better. A company with a racing expert on staff is a plus for your potential uses. If their literature proclaims that they do something to the "molecular structure" of metals be highly suspicious that they do not know what they are talking about. Metals are crystalline in structure. Avoid cryo treaters who make wild claims. Look for treaters who process for well known racing equipment manufacturers. Look at their equipment. The best equipment are circular vacuum insulated machines that use heat exchangers to cool the load. (Sorry, that is what we sell, and I couldn’t resist.) Any machine that allows liquid nitrogen to hit your part is highly suspect. Machines with spray bars that spray liquid nitrogen into the chamber to cool the part are in my opinion suspect, as we have tested against such machines and found ours have better results. The makers of such machines say the liquid nitrogen evaporates before it hits your part. The question becomes "does the light go out when you close your refrigerator door? That being said, careful use of such machines can produce ok results. Companies that call the process cryogenic tempering do not understand what tempering is. Sorry if I got a bit wordy, but if you decide to trust your hard earned money to someone, you should be sure that they will give you top value for it.

Generally speaking, pads last longer. We think that this is due to the fact that the rotors wear more evenly. Generally speaking, treated rotors are smoother when worn. They seem to resist getting ridges worn in them more. This gives the pad a smoother, less abraisive surface to run against. Therefore the pads usually last longer, up to twice the life. This of course depends on the type of pads. There are a lot of different formulations out there. Treating the pads will give you an increase in pad life of 10% to 200%. This seems to depend on the metal content of the pad, and again, there are so many formulations out there the only way to predict is to try some out. By the way, cryo also reduces warping and cracking of rotors. This has been noted in our lab tests, on the track and in normal use. Do not let anyone tell you that warpiong and cracking can be eliminated. As with any brake, run in is important. Normal run in procedures work just fine.

I doubt you're able to make claims like that in the ASM journals without data to support them and still be taken seriously. Perhaps you can provide some objective data that supports a 200% to 500% improvement in brake life? Skeptical as I am, I'd really like to be proven wrong. 　 We’ve done extensive testing on cryo treated brakes. We’ve tested more brakes than all other cryo companies combined. The tests were performed by independent laboratories that specialize in brake testing. Two different labs were used, Link Laboratories and Greening Laboratories. The brakes were tested to SAE 2707 Jul 2004 Method B. The results were that there was a two to four times life increase with treated brakes. We had brakes tested by the same method until they were worn beyond the service limits. The treated brake was 0.039" thicker than the untreated rotor when both were run on the identical cycles. The US Postal Service had Greening Labs test brakes that were supplied to it by vendors who wanted to sell brakes to the postal service. Many parameters were tested, including noise, pad wear, rotor wear, etc. Our brakes showed seven times the life of the second place Brembo brake. For cost calculations the USPS degraded that to 5 times the life. Remember, this was the USPS testing, not us. We now supply the postal service. We sell to many police units. They see increased life. A northern Illinois community went from getting 4000 miles on a set of brakes to 16,000 miles. A southern Wisconsin Sheriff's fleet is getting double the life as compared to OEM rotors. We sell to multiple fleets that give us similar data. A large manufacturer of brakes tested our process on their special police rotors. They got four times the life. (I can’t mention their name because they decided that they did not want to offer cryo treated rotors because of the potential loss of sales. I don’t want to meet any lawyers.) We currently process rotors for PowerStop. They also have tested the process via independent labs. We process rotors on a production basis for another large manufacturer who prefers to remain unknown at this time. Porsche has eliminated the need to change rotors during endurance racing by cryo treating them.

First of all, I will state that I own a cryotreating facility. I am also a metallurgist and co-chairman of the ASM (American Society for Materials) committee on cryogenic processing. A lot of things happen when you freeze metals to cryogenic temperatures. Yes, austenite is transformed to martensite and the martensitic crystal structure is bigger than the austenitic. (which really makes you wonder when some cryotreaters claim that they "densify" metals.) Other things like vibration, and heat will also cause austenite to transform. So if you put an engine together without cryogenic processing, the transformation will occur over time and really mess up your engine. Cryo also relieves some residual stress. Again, heat and vibration can do the same. That results in the part warping in use. We've seen untreated cylinder heads warp 020 inches in use. (I used to work for Fel-Pro.) In short, cryogenic processing stabylizes metals so these changes occur before assembly. So assembly is not everything. Careful assembly of stabile parts is everything. A lot of other things happen at cryogenic temperatures. Point defects in the crystal lattice structure change. The solubility of alloying elements decreases, causing them to do some moving. Vacancies in the crytal move out of the structure. Very fine carbides form, which enhance wear resistance. We think that we are making the distances between atoms in the crystal structure more regular, but that is theory at this point. Fatigue life increases. Yes, all of this is more important if you are running on the edge. And yes, you can on certain engines get a 400% increase in life. (We had a customer get 500% increase between rebuilds, and he was a national champion in his class.) There is a decrease in friction, but you are better off using a performance polish such as REM for that. Certain items such as valve springs last considerably longer. Our drag racing circle track and road racing customers get about a 600% improvement on valve spring life. And when you are spending $400 for a set of valve springs, making them last six times as long is a moneysaver. Is it snake oil? Porsche does not think so. And over half the NASCAR field runs on parts that we have treated. By the way, get your brakes treated as they will last two to five times as long. Cryo is worth the money if done correctly. Watch out for the guys with a dewar of liquid nitrogen and a styrofoam beer cooler. Go with an established firm.