Cryotempering Happy Time 2 stroke engine
- Thread starter chrisnbush
- Start date
chrisnbush
Member
670 miles on the motor, no changes to it. Power is now max, good torque low end (after a number of mods to the pipe) but "4 strokes" on upper RPMS still. Waiting for carb jet drills as needle is low as it can go and spark tip still wet and oily. Someone told me to bring stock jet (.7mm) down to .6 or even .5 as these 80cc motors run rich.
Just 2 flat tires (front, then rear) since the last post. I have tube swap outs down to 15 for front, a little more for the rear. Someday I will get tuffliners, whatever and attack tire lifetime issue. But now I just take spare tubes + pump in my backpack.
Enjoy the ride ! It is getting pretty cold up here in NH...
Just 2 flat tires (front, then rear) since the last post. I have tube swap outs down to 15 for front, a little more for the rear. Someday I will get tuffliners, whatever and attack tire lifetime issue. But now I just take spare tubes + pump in my backpack.
Enjoy the ride ! It is getting pretty cold up here in NH...
chrisnbush
Member
Cryotempering update
1239 miles on the motor now, if I get to 1500 thats my lowest total for a HT motor, if I get to 2500 thats my highest (both of these "benchmarks" were not cryotreated)
FYI for the update
cb
1239 miles on the motor now, if I get to 1500 thats my lowest total for a HT motor, if I get to 2500 thats my highest (both of these "benchmarks" were not cryotreated)
FYI for the update
cb
Flapdoodle
Member
I happened by chance to meet a fellow who was an optical glass salesman in a parking lot. He excitedly said "Those are the original Photo Sun" referring to my eyeglasses. "And they still work!" I was impressed that he could tell at a glance. After a little conversation he revealed that it was said the life of them could be greatly extended by getting them very cold. I had worked in ND where it got as cold as -55 F.
*IF* glass behaves similarly to metal, perhaps dry ice would be cold enough to cryo-treat metals. However, I have a fear that because of different thermal expansion rates, the chrome liner might lose its bond with the cylinder walls.
*IF* glass behaves similarly to metal, perhaps dry ice would be cold enough to cryo-treat metals. However, I have a fear that because of different thermal expansion rates, the chrome liner might lose its bond with the cylinder walls.
chrisnbush
Member
That is interesting. In my poking around there was mention of something called "shallow cryotreatment" which was at -70c, the temperature of solid CO2. I ended up treating this engine in a "SoLow" freezer, which is -70c - I left it in their for 48 hours.
I initially wanted to do true cryotempering, which is the temperature of liquid N2, but the cost of N2 was high, so I settled for the "shallow" thing. That being said, I have not seen anything indicatiing that "shallow" cryo treatment actually does anything EXCEPT Flapdoodle's anecdote above. I have to tell you I have a hunch it DOES do something, but it certainly would depend on the metal and possibly the thickness of the metal ? Looking back on it, the things that need to be harder on these motors are really just the needle bearings (and wrist, crank pins). The needle bearing cages being thin, like eyglass frames, I am thinking maybe it could help.
But Old Bob above seems to have experience with numbers of treatments. Unfortunately, I only have 2 engine markers for my statistics, both non-cryotreated, and both from different suppliers. One I got 1500 before the wrist pin bearings went, the other 2500 before the crank pin bearings went. So if I beat 2500, well, I am going to do it again (cryo treatment) as I have access to a SoLow.
Thats all I got...
BigKid
I initially wanted to do true cryotempering, which is the temperature of liquid N2, but the cost of N2 was high, so I settled for the "shallow" thing. That being said, I have not seen anything indicatiing that "shallow" cryo treatment actually does anything EXCEPT Flapdoodle's anecdote above. I have to tell you I have a hunch it DOES do something, but it certainly would depend on the metal and possibly the thickness of the metal ? Looking back on it, the things that need to be harder on these motors are really just the needle bearings (and wrist, crank pins). The needle bearing cages being thin, like eyglass frames, I am thinking maybe it could help.
But Old Bob above seems to have experience with numbers of treatments. Unfortunately, I only have 2 engine markers for my statistics, both non-cryotreated, and both from different suppliers. One I got 1500 before the wrist pin bearings went, the other 2500 before the crank pin bearings went. So if I beat 2500, well, I am going to do it again (cryo treatment) as I have access to a SoLow.
Thats all I got...
BigKid
chrisnbush
Member
1666 miles on my "cryotempered" motor
Well I beat 1500 anyway. 1666 miles, going for 2K...
I like my DAX rear mount Titan, but again more maintenance than I really want - chains, replacing bearings, etc. I have 1600 on it, all and all a better commuter bike than the centermount, smooth. But I am tired of greasy hands - at some point here (by the end of the summer) I hope to be working on a GEBE (Golden Eagle).
Funny thing is, despite the DAX Titan being a better commuter bike, if I get a GEBE think I would probably keep my centermount. They are the best on hills, and the best in the snow and I can fix the motor if it blows. AND motors are so cheap anyway. I got enough torque on my centermount that I can pull a trailer no problem (I made one out of PVC and bike wheels - have had 40+ pounds on it).
I will post if / when I get over 2K on this motor
Whatever
BigKid
Well I beat 1500 anyway. 1666 miles, going for 2K...
I like my DAX rear mount Titan, but again more maintenance than I really want - chains, replacing bearings, etc. I have 1600 on it, all and all a better commuter bike than the centermount, smooth. But I am tired of greasy hands - at some point here (by the end of the summer) I hope to be working on a GEBE (Golden Eagle).
Funny thing is, despite the DAX Titan being a better commuter bike, if I get a GEBE think I would probably keep my centermount. They are the best on hills, and the best in the snow and I can fix the motor if it blows. AND motors are so cheap anyway. I got enough torque on my centermount that I can pull a trailer no problem (I made one out of PVC and bike wheels - have had 40+ pounds on it).
I will post if / when I get over 2K on this motor
Whatever
BigKid
chrisnbush
Member
OK now got 2080 miles on my "shallow" cryotempered Happy Time 80cc motor. Bought motor originally from DAX for about 100 with shipping.
In August I will have a year on it - gotta be some kind of record. Well, it doesn't look like we are going to be able to get these little motors anyway. Probably good as they run pretty dirty. Soon I will pull the drive sprocket and replace it - I probably have 3K miles on it and the teeth are getting pretty sharp. Also pump some grease into it, into the fitting - I do this until it just starts to come out the drive sprocket bearings.
I am looking at changing it out when it blows, with a DAX centermount 4 cycle kit - he is selling one with a freewheel with his "Titan" (hua sheng I think) motor. I talk about DAX a lot, not promoting them really I am just comfortable with the supply from them at this point - although Duane has been pretty good with the service.
Well, later for now - ENJOY THE RIDE I KNOW I AM !
BigKid
In August I will have a year on it - gotta be some kind of record. Well, it doesn't look like we are going to be able to get these little motors anyway. Probably good as they run pretty dirty. Soon I will pull the drive sprocket and replace it - I probably have 3K miles on it and the teeth are getting pretty sharp. Also pump some grease into it, into the fitting - I do this until it just starts to come out the drive sprocket bearings.
I am looking at changing it out when it blows, with a DAX centermount 4 cycle kit - he is selling one with a freewheel with his "Titan" (hua sheng I think) motor. I talk about DAX a lot, not promoting them really I am just comfortable with the supply from them at this point - although Duane has been pretty good with the service.
Well, later for now - ENJOY THE RIDE I KNOW I AM !
BigKid
