Front Cam Snap Ring - Potential Problem...

[VDeuce]

I have a new 120R on my workbench with heads off for machining and cams out because I'm installing 662-2 cams. I noticed the front cam retainer clip (circlip / snap ring) was bent in a curve and not flat. Now I have a good snap ring pliers and I know I didn't damage this. I have done quite a few cam swaps and have never seen a curved snap ring.

So I go to a local dealer to get a new one as you really are supposed to replace these anyway. It's identical to the curved one I took out of the engine...

Then I went to a local independent (Otto in Sugar Grove IL) and got a new one from him - perfectly flat as I have always seen in the past and what I would expect.

In this first pic, the flat ring is on the left that I got from Otto. In the middle is the new one from a dealer and on the right is what was removed from the 120R.



In this pic, you can see just how curved the clips are.


Now unless HD is trying to put some pressure on this for some reason, I just don't see how in the world this is correct. The slot machined in the cam is certainly not on a curve, 

So, given the problem we have seen with a broken clip in this thread - http://harleytechtalk.com/htt/index.php/topic,50478.0.html, may not be all that surprising if that clip turned out to be curved as these are.

So what say ye - which would you put back in the motor?

[Clayster]

 

[Admiral Akbar]

I'd say heck no.. Depending on how it goes on if one end should pop out of the groove, the snap ring could work itself of the end of the cam..
The snap-ring should be perfectly flat so that it can absorb and distribute any forces along the whole edge of the ring and the ring grove evenly..  The die that stamped em is probably munged up..

Max

[choseneasy]

I would not be able to sleep with a bent one in the motor. Great post- thanks for the heads up!

[VDeuce]

A 50 cent snap ring can take out a $10k engine.

[Ohio HD]

That's scarey! 

[Jeffd]

I just bought a new cam kit a few months ago and the snap rings are now curved.  Mine fit well and it looks like they would be impossible to accidentaly pop off if properly installed. the ones I removed from stock cams were the same 2011 103

[rigidthumper]

The flat ring is intended for the 99-06 cams, the curved one is for 07-present style cams. By Part number, anyway.  Parent metal cam plates (new style) front cam end play is controlled by a .100" washer and that curved snap ring. Bearing style (early TC) cam end play in controlled by the bearing itself. You can use whatever you want.

[VDeuce]

I just bought a new cam kit a few months ago and the snap rings are now curved.  Mine fit well and it looks like they would be impossible to accidentaly pop off if properly installed. the ones I removed from stock cams were the same 2011 103

That's just the thing - we really don't know if they are purposefully being made this way, but I can't bring myself to think this is a good idea.

[VDeuce]

The flat ring is intended for the 99-06 cams, the curved one is for 07-present style cams. By Part number, anyway.  Parent metal cam plates (new style) front cam end play is controlled by a .100" washer and that curved snap ring. Bearing style (early TC) cam end play in controlled by the bearing itself. You can use whatever you want.

Interesting, thanks for that! Are you saying that it is safe to use either in the '07 and up, or are you really supposed to use the curved one? With that snap-ring failure on another 120R, it gets me a bit nervous to use it, but then again it could have been installation error.

[Herko]

The flat ring is intended for the 99-06 cams, the curved one is for 07-present style cams. By Part number, anyway.  Parent metal cam plates (new style) front cam end play is controlled by a .100" washer and that curved snap ring. Bearing style (early TC) cam end play in controlled by the bearing itself. You can use whatever you want.

Ditto.
Will add that bowed snap rings in general are nothing new. I used to buy late model OE's to go in kits...they were all bowed. On occasion I would get shipped a suitable sub aftermarket and they would be flat. Properly seat the bowed snap ring and all will be well.

[biggzed]

Every one of those I have installed (total of about 7 all '07 and up models) have been bowed. Never had a problem with one.

Zach

[1FSTRK]

I just bought a new cam kit a few months ago and the snap rings are now curved.  Mine fit well and it looks like they would be impossible to accidentaly pop off if properly installed. the ones I removed from stock cams were the same 2011 103

That's just the thing - we really don't know if they are purposefully being made this way, but I can't bring myself to think this is a good idea.

It is designed this way
http://www.arconring.com/stamped/bowed-external-retaining-rings

[VDeuce]

Thanks for the info on the bowed rings, that's new to me!

[rigidthumper]

If you want to use the flat one, install it with the .100" in place and check front cam end play. If the end play is not excessively loose or tight, you should be good to go. IMO, the bowed one works fine, and allows for expansion from heat, when properly installed.

[Admiral Akbar]

Learnt somthin new.. Thanks,

Max

[mike jesse]

You will also note that one side the edge is sharp and the other side has a slight radius as it came from the die.
I have always installed them with the sharp edge facing out.
It will fit into the machined cam groove with less chance of coming off.