Stomski Circlip Injector Tool Review

[Gordo2]

Today I installed my JE Piston pin circlips using the Stomski 23mm Circlip Injector tool.

Bottom Line Up Front

This is a great tool - it truly makes installing piston pin circlips quite easy.

I've read a ton of posts on how difficult it is to install JE piston pin circlips, and I have no doubt it would have been a challenge without the Stomski injector tool.

I purchased mine used, on E-bay for ~$65 shipped.


Using the Stomski Circlip Injector

Mr. Steven Stomski provides a great overview / instructional video showing how the injector works in this video: Stomski Racing Circlip Injector - YouTube

I made my own 2 minute video documenting a quick circlip installation on the engine - piston and cylinder mounted on the head studs / limited access room etc. - no kidding 2 minutes from picking up the circlip and explaining how the injector tool worked to an installed circlip.

I was going to add my video to YouTube, but I accidentally deleted the video


Meanwhile here's a few action shots of the injector:

Circlip inserted in the housing:


A quick line up, and press of the plunger and the circlip is installed:


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It was that easy...

Sometimes you get what you pay for, and in the case of the Stomski injector tool - it's worth it's weight in gold.


Gordo

[Flat6pac]

Even easier, try the install before you install the bottom row head studs.
Bruce

[KTL]

Good durable tool that is definitely a great tool to have. Avoids circlips flying across the shop (or into the engine) and cuts down the cursing to basically zero. Circlip removal is a different story......

[Henry Schmidt]

There have been a few failures of late (clips coming out of JE pistons) with some fingers being pointed at the Stromski tool.
The claim is that the JE clip is larger than the Mahle clip the tool was designed for. This means that the tool must compress the clip further than advised.
I use the Stromski tool and highly recommend it but the stories are floating around.
I will admit that putting the JE clip in the Stromski tool is considerably harder than installing the Mahle clip.

[porscheboy1]

When I put the J&E clip into the Stromski tool it distorted the tool transforming the end of the tool into a semi ellipse. It would not fit into the bore in the J&E piston pin hole. I therefore used the old Mahle clips to install my J&E pistons. This is my first 911 engine build, but I don't expect any problems using the Mahle clips?

[Gordo2]

Originally Posted by Henry Schmidt

There have been a few failures of late (clips coming out of JE pistons) with some fingers being pointed at the Stromski tool.
The claim is that the JE clip is larger than the Mahle clip the tool was designed for. This means that the tool must compress the clip further than advised.
I use the Stromski tool and highly recommend it but the stories are floating around.
I will admit that putting the JE clip in the Stromski tool is considerably harder than installing the Mahle clip.

Hard to imagine the clip popping out - I installed my last one in a piston, then realized I deleted my video, so I attempted to remove it.

I gave up - it wasn't worth the battle.

On a related topic - I did find this excerpt from JE's instructions a bit disturbing:

"DO NOT TRY TO SQUEEZE LOCK TOGETHER TO INSTALL. This will cause permanent deformation of the lock, thus not giving the appropriate radial preload."

No getting around it, you have to squeeze the circlip to insert it in the Stomski injector

Which, by the way, is really the hardest part of using the tool. Once inserted and set up correctly - injecting it in the piston is literally a snap.

Thanks for the feedback folks.

Gordo

[KTL]

That statement by JE is a bit of CYA. The clip has to be squeezed in order to install it. Even if you do not use the Stomski tool (manual method w/a strong hook tool or customized flat blade screwdriver) you're leveraging and compressing the clip to squeeze it smaller. That's the only way the clip will fit in the piston! I bet they're covering themselves for people who squeeze the clip closed, or further, to help w/installation?

I would make sure the wire diameter of the clips are the same before substituting the Mahle clips. I seem to recall the JE wire being a bit thicker than the Mahle, handling them recently. Also need to be sure the clip groove is of the same diameter. Theoretically should be the same since they're retaining the same size piston pin. For instance the 23mm pins from JE spec .905" and the Mahle pins are a gnat's arse larger at .9053" Probably not an issue there, splitting a 0.0003" hair?

[sjf911]

The first set of JE's I installed, I was able to get the first clip in with the pistons free with great difficulty but just could not get it to work for the second clip when installing the wrist pin so resorted to using the Mahle's which are definitely thinner and much easier to work with. On disassembly, there was no sign of an issue. The last set I used the Stomski tool to install the JE clips in both sides and simply don't see another option. I would like to know how you can get those bloody (literally) clips any other way. I didn't think to remove the lower head studs which might have made it almost doable. Are they designed with the idea that the pistons would be preinstalled on the rods before final assembly like you would for most other engine types?

[JohnJL]

i cut a 2" section off a cheap metal handled broom, push the clip in one end with a screwdriver, line up the pipe with the wrist pin, then use a 14 mm socket to push through the handle and pop the pin is in place.

ive only done 36 pistons with it but it was free and works 95% on the first try.

[BYprodriver]

+1 for the Stomski Racing circlip injector & the owner who is very helpfull on the phone! High quality material & machining & I can't imagene a circlip deforming the tool. I use it for Boxster engine rebuilding & it works great. I rarely post in this thread but just saw the title & had to endorse this business!