Cryotempering Happy Time 2 stroke engine

Discussion in '2-Stroke Engines' started by chrisnbush, Sep 9, 2009.

  1. chrisnbush

    chrisnbush Member

    I am considering trying this, there is a link on SpookyTooth for cryotempering these motors.

    Cryotempering is supposed to improve the quality of metal - it is used in a lot of industries for automotive stuff, brake parts, etc. According to the link, you can get an engine to last up to 4x as long by bringing it down to -300 deg F for "a couple of hours".

    I have a motor coming. My idea is to remove the magneto, wrap the motor in wet newspaper, and first place it in the freezer until -20. Then, after overnight, place it in dry ice at -70 in a cooler. Then, after a couple of hours, put it in another cooler and add a gallon or so of liquid nitrogen at -320 deg. F.

    I was wondering if anyone ever tried the service that SpookyTooth advertises, I think it costs $75, but that does not include shipping. I assume that they can control the rate of cooling to make it much slower (!) than my rough steps above.

    I am just toying with the idea at this point, as there is a pretty good chance I would just trash a new motor with my "treatment". But I don't know, I might just do it anyway. If it works, and I could get more than 2500 miles on an HT (my personal best at this point) it would be worth the $40 or so it is going to cost me in materials.

    Any interest ?

    Chris Bush

  2. spad4me

    spad4me Member

    Sounds interesting ,
    The motors are so cheap. you could buy a thats dax longtblock for that price.
    Post results .

    I think they do that for their deathrace motors.
  3. give me vtec

    give me vtec Active Member

    I think it would be worth it... I have a cryotreated 4g63 that I am putting into a 91 Galant vr4... when I get the money have the car painted.

    Cryotreating is good for a lot of reasons... SimpleSimon would probably know more than me (so maybe you should contact him and see what he says) but I say go for it.
  4. arceeguy

    arceeguy Active Member

    Honestly, I wouldn't waste my time.
    Cryotempering, porting, polishing, etc. are just trying to make the HT into something it isn't.

    High performance isn't in the DNA of the HT bicycle engine. It was meant to be inexpensive basic, motorized transport and it accomplishes those goals.

    If you have a 50cc engine, I'd buy a cylinder with cast iron liner and a slant head. Better performance and durability.
  5. If I were going to experiment with this I'd remove the crank, con rod, and any other steel parts and chill the engine in pieces, rather than assembled. Steel and aluminum contract and expand at different rates, cooling to this extreme will cause serious contraction and dissimilar metals might break under the stress. I'm guessing that crystallization occurs at these low temps and hardens the metal. I'm unclear if that same hardening wouldn't also make the metal brittle. I would bring the engine parts back to room temp very slowly and without shocks. Good luck.
  6. give me vtec

    give me vtec Active Member

    yeah thats pretty much the truth... if you want reliability you gotta go with the eho35 GEBE.
  7. GearNut

    GearNut Active Member

    I have studied this technique and will share what I know to the best of my knowledge.
    Each part would have to be done individually for it to work right.
    Every part that is steel or iron can be frozen in liquid nirogen with excellent results. Auminum, brass, or pot metal can be frozen as well, it just won't have as great of an improvement.
    It strengthens the metal (any kind) by causing it to freeze and contract at the molecular level to the point where it induces alignment of the individual atoms. Sorta like how a magnet works, but without mangetisim (no positive to negative electron charge specification).
    In typical metals, even hardened ones, the atoms are arranged in a haphazard way. Aligning them greatly strengthens the part as a whole.
    It will not harden metals like tempering will.
    No, you will not end up with a "super" metal with cartoon like strength, just a metal with extrodinary strength compaired to the way it was before.
    Here's some links on the subject to clear up whatever I may have gotten wrong:
    Last edited: Sep 9, 2009
  8. chrisnbush

    chrisnbush Member

    Thanks guys, I will update this with results
  9. chrisnbush

    chrisnbush Member

    Well, here is a status report.

    Liquid nitrogen equipment is expensive, you need a Dewars thermos (these cost 100s of dollars) to get a reputable welder supply place to give it to you, and they charge 7 bucks a liter for it. I probably could have borrowered the Dewars, but it can only be used for transport, it is either flask or canister shaped, you can't put a motor in them.
    I don't think putting liquid N2 (-196C, -321F) in a 6 pack cooler is going to cut it somehow...

    So I checked into dry ice (-79C, -109F), not as expensive, but I am in the sticks and the only supplier convenient (AirGas) wanted 5 bucks a 1 lb brick. I probably would need 4 pounds at least, and it was more than I wanted to spend. I also would have to buy a small 6 pack cooler as it would be best to fill the container as much as possible to slow the evaporation of the dry ice to treat as long as possible.

    I work at a college, and as luck would have it, the biology department let me use their "so-low" freezer, which is -80 degC. So ->

    1. I got my motor from DAX, removed the mounting studs + clamps. The motor comes without a plug, and I left the magneto in it, because, well I am lazy.
    2. I packed the motor in a plastic bag, and covered with several layers of newspaper to "bundle" it.
    3. I put it in a normal freezer for about 2 hours
    4. I walked it across campus and put it in the "so low" I went as quickly as possible so the motor wouldn't warm up too much

    I will leave it in the so low for 48 hours, then pick it up in a cooler, and reverse the process (put it back in a regular freezer for 2 hours, then bring it to room temperature).

    Probably out a hundred bucks (!), but I have plenty of good magneto's and if worse comes to worse I will have "partially cryotempered" parts.

    I know the temperature isn't low enough, but from what I understand about the process the higher temperature might have some effect, if you leave it in the freezer longer. The true cryotemper process, at least what is described in the link off spookytooth, is implied to be "a couple of hours".

    Probably get it on the bike by the weekend to see what happened. I am pretty sure this voids the DAX warranty, dont' tell Duane ha ha

    Last edited: Sep 14, 2009
  10. GearNut

    GearNut Active Member

    From what I understand, the true cryo treatment temperatures are soo cold that the electrons actually slow down in the individual atoms that make up an object. We are talking as close to absolutely frozen solid as you can get, where the atoms do not even move.
    Normally on the atomic level, all the atoms that make up an object are constantly moving, vibrating at a resonate frequency, bouncing into each other. Glass, steel, rubber, rocks, water, trees, cows, elephants, lions, tigers, and bears, oh my, ect. everything on earth.
  11. chrisnbush

    chrisnbush Member

    Yes - absolute zero is around about -496 deg F or something, N2 is -320, so N2 isn't that close to absolute zero anyway.

    From what I know about it so far, it is actually a crystalization of the metal. Metal is essentially a glass, the molecules are "frozen" where they are when they were molten - this is the definition of a glass - amorphous. But over time glasses will crystalize, even at normal temperatures. Old window glass does this.

    There IS something called "shallow cryogenics" which is down around the temperature I am at (-109F or something). As there are a lot of different metals and alloys involved in the motor (so some may benefit more than others), AND crystalization is not only temperature, but also time dependent, AND I am leaving the motor for 48hours I am hoping to reap some benefit.

    At my rate of motor use, it would take 10 years to say yes or no on any advantage. I had one motor that lasted me 1500 miles, another 2500, another just 400. I guess if I got more than 2500 on this one I would superstitiously conclude that it improves the motor, and do it again (what the heck). And the motor I have is from the same vendor I got the 2500 miles on.

    If the stupid motor isn't destroyed...


  12. give me vtec

    give me vtec Active Member

    sounds like you need an eho35 powered gebe kit... goodbye chepo chinese ****, hello quality Japanese precision.
  13. GearNut

    GearNut Active Member

    Oh I doubt the stupid motor will be destroyed. Maby it will last 3500 miles now....
    Who knows.
    I am intrested in your findings with this experiment.
    Venturing into the great unknown. :D
  14. Turtle Tedd

    Turtle Tedd Member

    I think these chinese motors are probaby all they can be for what they cost..kinda like a disposable diaper......
    Last edited: Sep 14, 2009
  15. GearNut

    GearNut Active Member

    What, stinky and full of s....... um, you get the idea.....:whistling:
  16. MikeJ

    MikeJ Member

    Instead of doing the entire engine, why not do just the cylinder and a couple sets of rings? (after all, whoever heard of a block, magneto, armature, or drive gears wearing out?) Maybe Spooky can set aside a few sets and sell them as "value added retail" parts. Swapping out a cylinder and rings is a job almost any bike owner can perform without special tools.

    My thought for the day...
  17. chrisnbush

    chrisnbush Member

    You have a point, but I would want to do at least the needle bearings and main bearings also, if only for the reason that this has been what has failed on my motors. I doubt strengthing the housing would help much, the housing never fails right ?

    I guess Chris Hill makes a business out of buying motors, and replacing the bearings right out of the box - for his "high end" models (I think I have that right) If you think of it, what ELSE in these hunks of **** would fail ? A piston or connecting rod probably isn't going to break. Well I know the clutch components, etc. fail. But a big source is the bearings.

    Even with the best bearings I think these motors are destined to fail probably due to sloppy tolerances. If you think about it, if the main bearings, let say, aren't completely mated to the crank shaft, there is any wiggle at all, then part of each power stroke is transmitted as shock to the bearings - like hitting them with a hammer. Over time thats what does them in, and thats why Honda, Mitsubishi, Robin, etc. are superior, one of the reasons anyway - they certainly manufacture to higher tolerances.

    I can't give up on these centermounts, I have tried rear mount friction 2 cycle (livefastmotors) and have a DAX rear mount titan. I like my Titan a lot, but have to say I get better overall performance out of the centermount - certainly not smoothness or quality - but performance. And that is before tweaking with tuned pipes, maybe spookytooth CMA carb. I might have had as good or better performance out of the tire roller, but they don't work in the rain, wear out the tires, wear out the rollers. I think the manual friction plate clutch just does a better job transmitting torque over centrifugal clutches.

    Of course everybody has preferences. I commute on my bikes 30 miles a day, and want to minimize maintance and I don't like to pedal (I am lazy). I wish another company would start making centermount motors. I don't care that Grubee "personally inspects the engines". If the Chinese can't manufacture these engines to better tolerances, it doesn't matter how much pulling of parts, testing, cryotempering you do...

  18. MikeJ

    MikeJ Member

    Hi Chris -

    I hear you. If you depend upon your engine for a livelihood (or at least have it contribute to it) you would want better of anything that limits use of your engine. We typically complain about whatever breaks first. Your bearings go out and it is reasonable to want better bearings. (I had a mount stud break in the mount; I complain about that. Then the extractor broke in the stud. Now I am pondering a fix to make the engine useable again.)

    Keep us posted sometime in the future as to whether cryogenic treatment was worth the cost. Some of us need to see "the experiment" results before we jump in and follow.

    Mike J
  19. MikeJ

    MikeJ Member

    I'm thinking too that these engines were once meant for the mud-poor farmer, who number in the tens of millions in third-world countries. They have to be cheap to be affordable.

    The Japanese have long ago figured out that they can copy American-produced items, make them smaller, charge less money, and reap in a fortune, because Americans will buy any item if it is cheaper. Their first Hondas were laughable. Over time, they learned Americans are willing to pay for improved, enduring, expensive alloy engines. When they started winning high-profile world-class races, Japanese racing products won credibility.

    There will always be a market for any product that is cheaply made but works and is easy to replace, as we demonstrate daily with these engines. With that, I need to fix my engine and go for a ride!

  20. arceeguy

    arceeguy Active Member

    I would not dunk the entire engine. If liquid nitrogen is cold enough to change the structure of metal, I don't think it would do the oil seals and gaskets any good. I still think it is a waste of time, but if you're gonna do it, do the crank, con rod, piston and cylinder.