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Wire Lock / Circlip installation HELP! So damn frustrating !

Engine Building Fundamentals

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I have seen many tips and tricks including but not shy of Andre's advice on how to install them. I guess i need to take my thumbs to the gym.Onto my issue. I have a set of JE-Carrillo Pistons for my 2jz with upgraded wrist pins from 100 gram to 120 gram tapered edges. Installing the first 6 before rod and wrist pin was no issue.

However when i got to the side to lock the wrist pin into place, i ran into lots of issues that I had not before. (very new to wire locks). While trying to install wire locks/cir clip style I could not do it with my thumbs at all, so i ordered a tool specific for the job. You can see on the first 6 they are completely seated into the groove as they should be. On the other side though its seems to be some in the groove and some of it is not fully seated in the groove as well as it should be. When trying to use a dull pic to help into place, it shifts the other side of the lock out a bit.

I have attached two pictures, because i want to know what is acceptable while avoiding any potential catastrophic failures. In closing, are they seated or are they far from it? I feel like the heavier wrist pins are possibly impeding and making it more difficult & complicated, but don't quote me on that. Thanks for any advice in advance!

(note the picture with the wire lock and the writing on the wrist pin is the one of concern, also it looks this way on all 6 pistons where the wrist pin and rod have been installed)

Attached Files

The way I check if a lock is correctly in the groove is to use a small screwdriver and make sure it can "spin". It won't spin easily but it should at least move.

If it doesn't move at all, or pings out, it isn't seated correctly.

If it doesn't look seated, it probably isn't. If it comes out, it will cause massive damage. Personally if you are unsure, first double check the pin against spec and if in doubt, contact a local engine builder.

And yes, we all hate wire locks. Next to worrying about snapping a piston ring when fitting it they are probably my biggest worry!

Just a note when it comes to installing cir clip style pin locks is to position the clip opening north or south; it’s very unlikely but not unknown that if the opening is east or west then it could (again extremely rare) ping out during operation as the force of the piston moving linearly the spring can compress.

I have myself spent many hours verbally abusing the manufacturers when fitting these; in time it becomes easier and there is a knack of doing it.

As for the security of the clip and making sure it’s seated I agree with Denis about attempting to move the clip slightly; sometimes this isn’t possible and can damage the piston in trying to do so!

There should be a slight bit of float in the pin, if there is you can physically shift the pin back and forth against the clips to make sure they don’t come out.

Hope this helps!

Do you mean the circlip can be moved side to side in the groove, because it isn't expanding to lock in place in the groove, because that's what it sounds like?

If so, either it was the wrong size, unlikely, or you've managed to deform and ruin the circlips by compressing them beyond their elestic limit - in other words, they're now junk and need to be replaced. SO DO NOT USE THEM, THEY WILL POP OUT, THE PIN SLIDE OUT, AND YOUR ENGINE WILL BE DESTROYED!

If you mean something else, please clarify.

No sorry; the cir clip shouldn’t move back and forth and most of the time will be so stiff it won’t rotate around either.

i mean the wrist pin / gudgeon pin can sometimes have float between the circlips on both sides; only sometimes; this would help you to know that the circlips have seated into the groove and won’t ping out; there are special tools out there for getting these clips in and seating them.

I believe pankl make a tool as it has been their pistons I have most of the experience building with.

Yes I completely agree if your not happy with the seating or if the clip is deformed in anyway don’t use it! If a clip comes out during operation it makes a royal mess of everything. That’s why I also mentioned the opening being north to south; it’s a slim chance but no to be avoided!

hope that clears it up

Sorry I was on vacation here is my follow up. I went to my machine shop to meet with my guru resource and here is what happened. He gave me an LS piston and said work on these cir clips I was able to easily seat and unseat them with no issues. The tool I purchased for the JE pistons seemed like a good idea but they distorted the cir clips so I wouldn’t recommend that tool for this application. The 2jz JE tolerance for seating circlips is like 20 mm and I have upgraded wrist pins so everything is just really tight. My fingers just are not conditioned enough to do it. The machine shop builder was able to with a lot of cursing but it’s now done. I also practiced on the old oem pistons no issue. So not sure why JE and upgraded wrist pins are such a bitch to put in the last 6 cir clips but next build I might think about my approach and there will probably even be more cursing lol. I feel defeated but glad they are ready to drop in the motor today


Glad you got it all sorted! the language in the build shop used to get very blue when we had a run of engines with this style of clip!

Tiny performance motorbike engines can be even worse! I have myself fired clips across the room and had to go have a quiet word with myself whilst trying to stop my thumb from throbbing! Where is the apprentice when you need him haha

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