"cryo" treating parts....

Engine builders for a VERY popular stock car series here in the US cryo their valve gear.(springs, retainers, valves,everything)

 

Some interesting info from these guys. http://www.performancecryogenics.com/history.html

I have not personally used it but know several road racer types that swear by it, and some drag racers. I work for a company that transports cryogenic liquids and have a fair understanding of the process. Next race motor I put together will get the treatment.

 

We have a system from 300Below at Richmond Marine. (http://300below.com) We've been cryo treating parts for years, there is no experimentation with us....we know it works and we have specific process cycles that are material and quantity dependent. Cryo treating is not a miracle treatment and it doesn't make any parts whole lot stronger....but it makes them much more wear resistant, much more fatigue resistant......"tougher" would be a good word.

We do lots of engine internals, transmission shafts, gearsets and brake rotors. We also do work for manufacturers on stamping and cutting machines. The cryo'd driveshafts for the hydroplanes and gearsets in 'class legal' boats we work on last way longer than untreated parts. We've got Mercury Marine TRS drives surviving behind 750ft/lb motors and pushing large (over 8500lbs) boats...if you know these drives you just said "HUH?!".

It works great on aluminum parts as well. Aluminum cylinder heads, gear cases, and pistons respond well. When you cryo -treat pistons we've been able to tighten up bore clearance slightly for better piston stability.

Any of you guys doing sewing/upholstery/top work? Treated sewing needles last something like 500 percent longer. Spot welding or spray welding???? Oxygen free copper nozzles and electrode tips and have triple the life time. Saw blades, knives....you name it.

It even works on polymers. You got nylon slides on a machine somewhere? They'll last way longer. The old lady's nylons? Much tougher when cryo'd. Light bulbs? The tungsten filament last longer too.

Things like axles, rifle/shotgun barrels, etc run about 50 bucks a pop, complete motors (disassembled and degreased) run in the 350-500 dollar range, transmission internals vary but typically 100-150 bucks gets all the guts treated. Firearms, engines, trasmissions (boat and car parts) are typically priced per part/assembly and bulk parts/materials are typically priced on a per lb basis with a sliding scale.....meaning that the more you do the cheaper it gets.

PLEASE keep in mind that this is a low production process. The parts are cold cycled at minus 300 degrees for up to 48 hours (which uses plenty of LN2) then there is a very important low temp (275-300 degrees F) triple temper process we follow up the cold process with. Its an expensive process to run and we run in 'batches' so timing is everything and so is volume.

If your interested in having parts treated drop me a PM or call Mike or Tom at 585-734-8733 for a quote.

-Bigchief.

 

"Chilled" iron is a process in which the iron is poured into a mould (sometimes made of iron or steel as well) that cools the outer surface of the casting much faster than the interior....this allows more carbon to reside at the parts surface making the part harder/more wear resistant/tougher at the surface. Since most of the lifters in the US are made at only a few companies I would surmise that this process is used on most, if not all, lifters.

Is the cryo treating process advantageous for your lifters? Yes. Worth it for your application? Maybe not. If all your doing is a cackle motor/glorified noise maker you can leave the valve spring pressures down somewhat in order to save wear and tear on the valvetrain. All the motor has to do is start, idle around the grounds and bark (loudly) when you blip the throttle. You can save yourselve alot of money and aggravation over the long haul by running standard valves (be sure to use bronze guides if your running alcohol and/or nitro otherwise you'll kill the valve stems and guides) and just enough spring pressure to get the job done. Use a cam with lower lift numbers and a mile of duration and a short lobe separation (104 degrees). The long duration and short lobe separation will give you that killer idle while the low lift allows you to run softer valve springs which are much more forgiving on the rest of the valvetrain. Run'er a little rich to save the motor and let it do the talking!

If your gonna do the lifters you might as well do the cam too....but again, probably not necessary at this level.

-Bigchief.

 

Connecting rods are one of the most important items to cryo treat. If you watch high dollar engine parts you may have noticed that Oliver and others started offering 'long life' aluminum connecting rods......ones that used to be tossed out at 50 runs are now in there until the motor is toast (200 runs)....guess how they pulled THAT off?

Cryo.

-Bigchief.

 

I used to work in a cryo lab at the University of Arizona.

Liquid nitrogen is cheap. Hospitals use it alot to freeze cell colonies. The dewars it is stored in are cheap and easy to come by, non pressurized also. We used to liquify Helium also, which is about 4 degrees Kelvin, thats 4 degrees away from absolute zero. Liquid nitrogen is 77 Kelvin.

The Hubble space telescope was built at UofA, and the labs building the pieces used our stuff to simulate temperatures in space, would basically pour it over parts to test durability.

Definitely worth doing if you can get someone to give you a fair shake on price.

 

My buddy lives in broken arrow, he has a lot of stuff cryoed, cryo mainly delivers high wear characteristics, not really tensile strength etc...

 

have done that to,,but i also dry iced them

 

The dewars your thinking of from your laboratory are not the same as the tanks used in delivering LN2 under pressure into a process/system. I too work in a lab for my 'real' job using dewars of LN2 for SEM-EDS, FTIR and various sample prep techniques. The LN2 tanks used for the cryogenic tempering processed are pressurized (22lbs or 50lb blow-off valves typically) 180, 200 or 240 liter pressure tanks. Hospitals and universities have large contracts and typically buy the stuff by the truck tanker load....when purchasing at that quantity you can get it down to about 60-70 cents per gallon. When you buy it from a gas supply house/welding supply house the costs to us at lower volumes is typically about 2 dollars a gallon plus tank rental plus delivery charges (DOT will not allow you to haul LN2 on your own trucks). Runs typically take 100-150 gallons (two to three 200 liter tanks or more if the processor is really full). The process is time consuming, you have to open and unwrap every part and document its origination point, contact info and condition, insure that it is clean and grease free, spray it down with a protectant, package it carefully in the cryo freezer and set-up the run. Three days later you get to pull the frozen parts out and load them carefully into a tempering oven and repeat the process with heat. ....there's more science to the process as well, its not a matter of just tossing parts in a freezer and hitting a button.

Parts are not simply dipped/dropped into LN2 and it is certainly not poured on to the parts....that would impart more stress into the piece instead of stress relieving the part. Liquid nitrogen does not contact any of the parts at any time during the process if its done correctly. The LN2 is delivered via spray bars that release vapor in a very well controlled rate over covered/protected parts. The cryogenic freezer idles at minus 110 degrees. Once the LN2 control system is activated LN2 is metered into the spray bars and the temperature drop is controlled to less than one degree per minute until you reach a temperature of minus 300 degrees. The warm-up is also a very well controlled process, using more LN2 to slowing bring the parts upto minus 110 degrees. Cycle times and rates vary depending on material types and amounts of materials in the processor.

The cryo equipment is not cheap, the process materials are not cheap and a good portion of the costs go into the electric required to run the cryo equipment and tempering ovens.

That is why many places (like ours) will collect and run parts in batches. It makes the process reasonably profitable enough to justify the high equipment and materials cost. ....and to try and give everybody a "fair shake" on price.

-Bigchief.

 

I've gone back and read all the links now, where have I been? I knew that Studebaker used to cure their raw cast blocks through at least one winter and knew of other cold treatments but not of this. If you are putting a several grand in a engine or, as many of us do, build older and harder to find engines it makes sense to spend a few hundred to make it last. Finally some great high tech that isn't ugly! Thanks to all who have shared this!

 

Ive never heard of this till now. Why arn't all machine shops offering this to their customers????? I can only imagine how many times this could have saved me a ton of money. I still cant believe Ive never heard of this, If I built engines for a living, you could bet I would offer it. I wish I knew about this sooner, I just had all the machine work done on a 454 and its assembled now........The next engine will be cryo treated.

 

i can tell you first hand it works!!!i built offroad rigs ,manly rock crawlers.we went from breaking front axles/axle joints at every event. to making a whole season without failure.we would treat the front&rear shafts.gears,output shafts,yokes.drive shafts.ive heard of guys treating there gun barrels,brake rotors.crankshafts /rods...

 

I've stayed out of this string until now, and am really surprised at how many have never heard of this.
I knew about it better than fifteen years ago, concerning treating rifle barrels to make them more accurate. Yes, it does work.....less vibration, better wearing characteristics, everything that has already been said. (You can treat a mediocre barrel and turn it into a good barrel. Like wise, a treated good barrel can become a tack-driver.
Yep, you bet my race motors are going to get treated, and those aren't really hard to find.....(yet).

Roger

 

Cryo promotes better granulair alignment, but is also used for de-stressing metals at the same time. Voids or imperfections in the steel’s microstructure are eliminated. Lamins terms, you freeze a bearing or sleeve to shrink it making it easier to install, know imgine to get the metal so cold that you make it self compact itself at the molecular level. Forcing the grains in the metal to fall into optimal alignment. Making it a densier material, but more brittle metal. Cryo-shrink is used a lot in fracture critical testing on aircraft for high allititude endurance testing.

 

Many engine shops don't offer the services because:

1 - Its not a cheap business/process to get into. The equipment is expensive. The process does not lend itself to a production environment. Its long and slow and expensive.....exactly what you don't want if your trying to make a profit of some kind. We offer it up as a service to our engine customers but if thats all we had to work with it would be a hard business to self sustain.

2 - The equipment is computer driven and you also need to understand alloys and the effects you can have with different tempering operations.....requiring a some knowledge of metallurgy. Both of which scare some shop owners away....especially old school shops.

3 - Many shops/people and some engine builders still think of the process as 'snake oil'.

4 - It doesn't change the appearance of the parts. I wish everything we cryo'd looked cool like it was dipped in four miles of candy blue clear coat....but it doesn't.

5 - If the customer is on a budget its sometimes cost prohibitive. For a 'cruiser' motor that sees a few thousand miles a year?....honestly probably not worth the expense. A real hot rod motor that gets abused and/or is somewhat rare/hard/expensive to build or has inherent wear issues on certain components (ie hemi, W-motor, flathead, FE, Y-block, Hercules, ect) then its money very well spent. Race motor? A must do as far as I'm concerned.

-Bigchief.

 

USAF barely uses to as much extent as the Navy. Navy refined it for their carrier landing aircraft. Except the navy uses a combition of cyro vapor / gas charged hold vessels ( hydrogen/ nitrogen/ oxygen) for different hardness allowances. The nice thing Cyro is that you can have one machined component with different hardness properties thru out. Why?? Where would you perfer critical failure at? At the mounting point on the aircraft, where it would cost millions to repair, or lower where a trunnion or axle lever is so all your replacing is a wheel and some consumable components?

 

Big thanks to everyone who brought somthing to the table. Ive learned alot and am sure Im better off for it. Thank you.

 

I have a computer control unit that is about 24" diameter and about 36" deep. If someone is near Indy and has some knowledge i am up for trying some parts..

 

A lot of real smart puppies on the "Hamb"

 

Puppies... and asses.

~Jason

 

Been reading this thread with interest.

Lets say you have a block all machined. So, if I understand correctly, it is exactly how you want it, but the internals are stressed.

You cryo it to relieve the stress. Doesn't this have the potential to alter the geometry of the block since it was machined "as stressed"?

Is it adviseable to machine it close to specs, cryo the block, and then machine it again exactly, (and perhaps cryo it again)?

 

Great thread. I have learned a lot. My application is a supercharged Mopar Flathead 6. The 1.63 rod/stroke ratio will provide plent piston-to-cylinder wall friction. So here is my question.

How do cryo'd cast pistons compare to non-cryo'd forged pistons for durability at high piston speeds?

N B R

 

We havn't seen anything move around appreciably before/after cryo'ing fully machined parts. Ideally it would be best to do all the hard machining (cutting/grinding processes) first then cryo then finally do the final hone on cylinder/journal bores and polish the crank. ...but I certainly don't loose sleep over treating a fully machined part.

 

They don't compare. The casting will still fail under the same conditions it normally would when you surpass its design limits. The piston expansion rates are slightly more controlled and the part will wear better but you'll still collapse/break a cast piston well before the forged slug is even breaking a sweat.