Teflon wrist pin bushings...

[ErcseRacing]

Building a 2276 for a friend and for the first time I am using some bugpack Teflon bushings that I got from work. Are they supposed to be this free? The picture has the bushing pushed as far as the cylinder wall will let it come out if you know what I mean

Is this ok? The piston at BDC will not position itself under the skirt of the cylinder so I don't have to worry about that

Any feedback will be greatly appreciated... Thanks

Nate Ercse
SoCal Imports

[modok]

That's not right, use the clips

they are not for slipper skirt pistons

[Howard 111]

Those may be slipper skirt pistons which would account for the thick Teflon buttons fitting, I'm not sure.

But those buttons must weigh a ton. Use the clips.

[bowtiebug]

x 3 use the clips , that will never work ..
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[esde]

The buttons are only good for pistons with a full skirt, such as Mahle/ Cima

[Quokka42]

Actually, the buttons aren't much good for anything apart from lightening your wallet by a few dollars - they certainly aren't meant for slipper skirt pistons, though I can't tell if that's the case from your photo. Even when used in the correct type of piston, they tend to come out against the cylinder wall causing all sorts of problems. Buy a set of circlips, install them with the flat side out, and never worry about that part of your engine again.
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There has only ever been one man who was perfect, and they nailed Him to a cross.

[mxracer]

[mark tucker]

they dont work with those pistons.and they do not cause issues unless not used properly or something is rong.

[Quokka42]

Run them for a while, then check out the rings. It is not clear how much is due to the bits of plastic wearing off, and how much is due to them rubbing oil off the cylinder walls, but they do harm the rings. I have seen them actually fail, as strange as it seems - we suspect that, as they aren't able to hold the pin exactly in the center of the piston, it moves then starts to work itself to one side. They aren't that heavy, but they do tend to trap oil and other gunk inside the pin, affecting balance. Again it's a hard one to pin down, but why cause yourself that kind of grief when the original pins are superior and there are better alternatives available?
_________________
There has only ever been one man who was perfect, and they nailed Him to a cross.

[Bruce]

[Quokka42]

Ya gotta love the internet!

I saw pictures of guys who set fire to their own pants earlier today and seem to have gotten away with it - but I'm still not going to recommend it to anyone (you're welcome to try if you like, though.)
_________________
There has only ever been one man who was perfect, and they nailed Him to a cross.

[craigman]

I personally wouldn't use them. In my opinion, there for racing use only that gets taken apart often.
I saw a motor one time that used them on the street, wasn't a pretty site.
Pieces were stuck in the rings on one piston, and on another it got wedged in sideways and groved the cylinder.
Maybe they were put in wrong, don't know.
Just a good set of True Arc keepers for me!

[Bruce]

[AlteWagen]

Ive used teflon buttons on several builds over the years and never had any problems people have described. No oil trapped in the wrist pin, no particulate in the rings, no debris trapped in the button that caused scoring on the cylinder, nothing to cause concern. The last set is still going strong after 90K miles. I did a ring and bearing rebuild at 70K and saw no strange wear patterns due to the buttons.

I do not recommend the super cheap ones that are out there. I was given a set and the fit was terrible. Very loose in the wrist pin and too wide that caused them to bind in the cylinder. Yes they were the correct size for the p&c set. I can see the problems reported if using a poor fitting part.
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[Quokka42]

[AlteWagen]

I only use them on builds that use a cast crank.

Because of the flex of the crank the wrist pin really beats the hell out of the clip which makes it incredibly difficult to remove the pin later on. Using stock/tru arc/spirolocs in that type of application would cause more damage to the pistons making them useless at time of rebuild.

Do I recommend the use of a cast crank? NO

Do I use teflon for all builds? NO

Do they work form many? Yes, especially for builds that will be torn down routinely.
_________________
Grapes of Wrath $200 Engine Rebuild
Official Dual Carb Thread
Cylinder Head Quick Reference Sheet

[slalombuggy]

I had them in my 1776 for 15 years. Never saw any adverse wear on any part. Everything looked as good as the day I installed them and I drove the hell out of that motor for 10 years every day in the summer as well as autocrossed it for those 15 years. No ring wear, the pins were never full of oil and it didn't wear grooves in the cylinders. I have seen them wear out cylinders, but that was from lazy people who refused to change their oil. I've seen more damage from novice engine builders who didn't get the snap rings seated correctly.

No They won't work in the OPs application, it's a slipper skirt piston.

brad

[mark tucker]

Ive seen more true arcs effup more stuff.spirial locks are just a real pain in the fingers. never seen a teflon button hurt any thing,yes some do let oil into the pin, you can drill them to let the oil in&out,Ive used 94 buttons in 90.5 pistons with the light pins by machining the buttons down to fit the pin tightly and having about.010-.020 cylinder wall clearance(buttons to cylinder). cb now makes the buttons for the light pins....but sent rong ones last time I ordered them so i just made another set(I have several sets of 94 buttons) I also lighten them up a bit for some motors.)the only time I have seen any issues would be when the "builder"(aka guy slapping it togeather) failed to clean the cylinders swarf. The piston&cylinder assy are not ready to assemble right out of the box. but saddly a lot of "builders" do just that. and wonder why the rings dont last.

[modok]

Some of the nicest pistons and engines I've ever seen use round-wire clips, although they usually have slightly different design VS the cheap ones, but all could be done. I'll make a picture of it sometime.

It's the same as everything else; it can be done right and it can be done wrong. A lot of ways work when done right, including the teflon thingies.