No More Circlip Problems

Mexicano

Mexicano
Maybe some of you remember my thread about the piston pin clip that got broke and blow my engine, here is the solution for such problem:

FROM A TEFLON ROD

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USING A MICRO LATHE, I MADE THESE TWO TEFLON BUTTONS

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HERE IS HOW THEY WORK

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Hope this helps to all of you,
 
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Tinne & Mr. Aerox:

YES, I used those Teflon buttons instead of circlips, no test yet on my scoot but I used them years ago in many many racing vintage porsche engines (8,000 to 10,000 r.p.m) and never had any problems with high temperatures or friction...Teflon is almost indestructible.
 
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i think ur a brave man to use them,
i thingk ur just better off using clips and triple checking there in proberlay
but well done if it works ive neva seen any thing like it b4
 
Alex ice:

Those button are also used in radio control plane engines, those little bastards spin to 20,000 to 26,000 rpm's, believe me...this is proven technology.....the clips broke often and cause a disaster, Teflon will never let you down!

Tell you this...I knew this before and when I was to assembly my engine for the first time I tought about the Teflon buttons but couldn't get te teflon rod at that moment, so I decide to give a try to circlips (You know, I want it now!!!)......when I blow my engine I was so mad be cause I KNEW IT!!!
 
Mex,
Looks like a great idea to me, but I have a few questions:
1. Are the buttons flush with the outside of the piston? Please post a couple more pictures.
2. How hard is it to remove the buttons once they have heated up and melted a bit?
3. This has to be adding a somewhat considerable amount of mass, I wonder if it is costing you some rev's?

I do commend you on a possibly great solution to one of my complaints, that is the ridiculously tiny circlips. I don't know why mfgrs won't make the small-end at least 16mm, it would be a lot easier to deal with.

scootertrog
 
Scootertrog:

1.- The buttons should flush out the pin housing just to get in touch with the cylinder,they have to be "hand sanded" until the pin can be pushed by hand into the cylinder without any problems, they have to be "rounded" a little bit to get the same radius as your piston/cylinder wall. I will post some other pics tomorrow so you can see them on the piston.

2.- No problem to remove them, they are the same diameter as your piston pin so they flush free inside the pin's hole, they do not melt, Teflon is a high temperature resistant material, you could melt your aluminium piston first.

3.- No way to add a considerable mass, teflon is very light, I will check the weight tomorrow in a precision scale and let you know.
 
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Eoin70:

You have to fabricate them using your comon sense and patience, tolerances are very important, if it fits loose it doesn't work, if it is to tight against the cylinder it could harm the cylinder's wall.....hand finish of the button is a most, once it is close to tolerances in my lathe I use sand paper to make it fit smoot.
 
Pr0ve:
Yes they are pressing at the cylinder wall all the time, this is the way they "hold" the pin in place but no problem with that, Teflon is a self lube material and won't harm the cylinder, it is a fluoropolymer resin that have exceptional resistance to high temperatures, chemical reaction, corrosion, and stress-cracking and extremely Low Co-Efficient of Friction
 
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Ah....I see, so these buttons just serve to make the wristpin longer (self-centering), they don't actually hold the wristpin in position like a circlip would. Very cool. Do they have to touch the cylinder wall, or can you have just a tiny gap? I wonder if it would be a good idea to drill a hole down the center of the button (chamfering the hole edge) to let oil pass through the button)? What is the life expectancy of the button - longer than the steel circlip?
I see the weight is about 3x the circlip weight. Nice scale btw, where did you find it? The porno shop next to the scooter store sells them to weigh drugs, but they want too much money for them.

scootertrog
 
scootertrog:

Yes the idea is to make the pin longer enough to self-center it, no gap between cylinder wall is recomended, about the hole at center...good point...never try it before, maybe a good idea!

I got the scale for $40.00 Usd. in a web shop....it is not a cheap product but it worth it, very usefull for varietor rollers
 
mhrlover said:
interessant, ben al11 benieuw ,hoe die erop krijgt met zuiger + as.
en heb je geen compressie verlies?

LOL, this guys is asking if you don't loose compression.

What the hell?

MHR Lover, these aren't pistonrings. How the hell would they lower compression!?!?

It gas absolutely nothing to do with it.
 
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