FREE needle bearing spacers 4 high RPM

[Jayraye39]

I thought about the brittleness of the cast aluminum however they're so little side to side play on the actual crank arm itself that it won't have enough Force to break it been hitting wide open throttle just to test it cuz I have a new jug coming seems to be fine I noticed the vibration isn't that noticeable to the added weight it just vibrates when I'm in the high RPM range but that's normal

 

[Jayraye39]

Not to mention when aluminum is heated it's flexible and not as brittle as cold

 

[ImpulseRocket]

Not to mention when aluminum is heated it's flexible and not as brittle as cold

Yes, the good old "Ductile - Brittle" transition. An annoyingly narrow band of temperature that most metals experience. With iron/steel they discovered that this temperature range was conveniently the difference in temp between the North Atlantic and the South Pacific. The Royal Navy in particular found that the Armor they made at home was brittle and failed to stop shells in the cold North Atlantic ocean, but in the warm South Pacific it was perfectly ductile and able to do it's job.

What's really amazing is the transition between these two properties is often quite narrow, within 10 to 20 degrees of temperature (in Fahrenheit) for most metals.

Did you know that there is one metal that actually does not display this behavior that is typical of pretty much all other metals and most metalloid elements?

Did you know that it's Aluminum?

Aluminum has a face centered cubic structure in it's crystalline form which causes it to have an almost imperceptible yield-strength temperature sensitivity. It's actually quite fascinating to see it at work. Even at cryogenic temperature levels it is able to resist crystalline fracturing.

 

[Jayraye39]

Yes, the good old "Ductile - Brittle" transition. An annoyingly narrow band of temperature that most metals experience. With iron/steel they discovered that this temperature range was conveniently the difference in temp between the North Atlantic and the South Pacific. The Royal Navy in particular found that the Armor they made at home was brittle and failed to stop shells in the cold North Atlantic ocean, but in the warm South Pacific it was perfectly ductile and able to do it's job.

What's really amazing is the transition between these two properties is often quite narrow, within 10 to 20 degrees of temperature (in Fahrenheit) for most metals.

Did you know that there is one metal that actually does not display this behavior that is typical of pretty much all other metals and most metalloid elements?

Did you know that it's Aluminum?

Aluminum has a face centered cubic structure in it's crystalline form which causes it to have an almost imperceptible yield-strength temperature sensitivity. It's actually quite fascinating to see it at work. Even at cryogenic temperature levels it is able to resist crystalline fracturing.

Yes it is quite fascinating I am a aluminum welder for Skyline structures and bridges when MIG welding or TIG welding aluminum the speed in which you travel is much quicker than any other metal there's a certain point when the metal gets hot and starts to deform then instantly it melts if you don't move quickly that's why aluminum is so good for heat conduction also a great metal for any costructure because of its durability and light weight. Just like our mag rims and some bike frames there is a flex and it give to the aluminum unlike the steel sometimes that's good sometimes that's bad but for spacing a needle bearing for free I think this application works

 

[darwin]

Yes, the good old "Ductile - Brittle" transition. An annoyingly narrow band of temperature that most metals experience. With iron/steel they discovered that this temperature range was conveniently the difference in temp between the North Atlantic and the South Pacific. The Royal Navy in particular found that the Armor they made at home was brittle and failed to stop shells in the cold North Atlantic ocean, but in the warm South Pacific it was perfectly ductile and able to do it's job.

What's really amazing is the transition between these two properties is often quite narrow, within 10 to 20 degrees of temperature (in Fahrenheit) for most metals.

Did you know that there is one metal that actually does not display this behavior that is typical of pretty much all other metals and most metalloid elements?

Did you know that it's Aluminum?

Aluminum has a face centered cubic structure in it's crystalline form which causes it to have an almost imperceptible yield-strength temperature sensitivity. It's actually quite fascinating to see it at work. Even at cryogenic temperature levels it is able to resist crystalline fracturing.

That last paragraph, what exactly are you trying to say? In English please! Me be thinking that's a copy n paste job from Metallurgy.com.

 

[ImpulseRocket]

That last paragraph, what exactly are you trying to say? In English please! Me be thinking that's a copy n paste job from Metallurgy.com.

Maybe use the internet and go to Metallurgy.com to understand it.

The simplest way I can describe it...

The way the atoms are stacked with one another when a metal goes crystalline has various types of structures. What this mainly has to do with is how each crystal shares atoms at the molecular level with the other cubic cells around it. A Face Centered structure means that in a cell an atom is shared at the face of each side of the cube as well as at each corner with the cells around it but there is no central atom in the cubic cell structure. In contrast to a Body centered structure where it has the same shared corners like the Face Centered, but with one atom the in central body of the cube and no atoms sharing at the sides (face) of the cubes with the ones next to it. Thus, Face centered and Body centered.

Not sure how much simpler I can go than that. I can try if you need me to.

Aluminum, gold, and copper (among a few others) all have a Face Centered cubic structure. Notice that they also all share somewhat similar properties in how they behave when it comes to ductility and thermal coefficients.

 

[Wevil Knievel]

That works

Washers like that can be found at Ace Hardware look in the Bronze bushing/spacer/washer section
Ace also has Nylon or Aluminum spacers/bushing/washers

Softer more malleable metals or nylon washers would be best. Something that doesn't disintegrate and leave metal shards inside the engine no matter how soft they are is ideal but good lookin out bro.

 

[Jayraye39]

Looked at them again today. Rode about 65miles so for. Washers show no sign of shaving or any cracks. Seeing that its the same exact metal that the bearing and crank arm come in cantact with i dont think their will be any problem with metal shards in the case. If that was the issue then their would be metal shaving in the case already without the washers

 

[Jayraye39]

The only metal softer than aluminum that is readily available would be copper. Copper will melt from the HIGH temps under the piston. Not to sure about nylon. That would melt also. I think you mean teflon. That would be ideal but remember this is a post about a free working solution.

 

[ImpulseRocket]

The only metal softer than aluminum that is readily available would be copper. Copper will melt from the HIGH temps under the piston. Not to sure about nylon. That would melt also. I think you mean teflon. That would be ideal but remember this is a post about a free working solution.

The aluminum piston would melt long before the copper ever would. Aluminum melts at just over 1200F. Copper melts at just under 2000F.
Also, without heat treating, alloying, or work hardening being factored in (aka - elemental form), aluminum is also softer than copper.