Poor parts and worse poor attitude.

circlips -info from speed pro

https://books.google.com/books?id=p2L-R ... ps&f=false

o0norton0o said:

From a physics point of view, I would argue that the weight of the return wire on the ends of the wire circlips can act as a bob-weight to compress the circlip as it changes direction

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Right, inertia not g-forces. Sorry, just being nit-picky

o0norton0o said:

So, perhaps wire circlips are not the substandard part I imagine them to be, and my circlip incident was a function of not seating the circlip properly during assembly. I did replace them with the cut steel circlips and reused the same pistons, so the wrong circlips have remained in place for more than 20 years without incident. Maybe I'm getting lucky there.

Jim, I saved all 4 of those wire circlips to remind me of this incident and how a very small mistake can screw up a lot of good work... I supose that's still true...

From a physics point of view, I would argue that the weight of the return wire on the ends of the wire circlips can act as a bob-weight to compress the circlip as it changes direction if the circlip is aligned horizontally, where as the cut steel type have less mass at their tips and also seem to be harder to compress... which seems to me would make them harder to dislodge.

*I'm certainly not trying to argue with the likes of Jim Comstock and Jim Smith who both would say the wire circlips work fine. There's been more than a few people who have had their wire circlips pop out, and you both could say they were seated impropperly in every case. There's no way to dispute that except by each person saying that they thought they seated the circlip properly. As the cases of this add up, it seems that there are 2 scenarios. Either people fuck up while seating this particular circlip, or this particular circlip has a greater propensity to fail than the other options.

...Sorry to hijack the thread slightly, I was under the impression that the wire circlips were a known deficiency, and am seeking a clarification... thanks

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As usual Comnoz is spot on and likely a bit too gentle when he says “I don't think I would say all wire circlips are no good”.

To repeat what others have already stated, the round wire circlip is the lowest mass keeper and literally all that is used nowadays on modern pistons, especially in performance applications. I believe the round wire circlip is used exclusively by Wiseco/JE on the myriad piston designs and millions of pistons they sell. It might not be the best design out there, just way ahead of whatever is in 2nd place (how's that for being diplomatic).

When properly installed in the correct piston groove and employed with the correct wrist pin design, the round wire circlip is never (I know, never say never) going to be dislodged and the only way to remove the pin with the wire in place is to destroy the piston.

With a properly matched piston, circlip and wrist pin, as shown below, it is virtually impossible to push the pin past the circlip, as any force causing the wrist pin to impinge on the circlip, wedges the circlip into the groove, causing the circlip to embed even further into the piston, thus the piston must literally be destroyed before the pin could ever move past it. If you conduct such an experiment in a press, it will destroy the piston before the pin ever moves out of the piston.


Now of course we’ve all experienced issues like you describe (me included) where some doorknob (in my case a PO) put a simple snap ring in a keeper groove cut for a round wire circlip, and when the tapered end of the wrist pin thrust onto the snap ring, the force tipped/flexed the snap ring and easily pushed it out of the groove, freeing the wrist pin to perform cylinder wall damage sufficient to require resleeving the cylinder. Thus another example of mismatched knowledge and parts.

Exactly my point, mismatch is your problem, no more no less.