Well, this sucks, but it could have been a LOT worse.

I was on my home from work and heard a "ticking" noise, and at the time I thought that it was just an exhaust clamp that had worked itself loose. However, after I pulled the car into the garage and listened to it I realized it was certainly NOT an exhaust leak. It was very easy to tell that the noise was coming from under the drivers side valve cover...so I then thought make a rocker-arm had worked loose. But after I took the valve cover off I saw the real reason.

This is what's left of one of the expensive titanium retainers;





Thankfully the valve didn't drop into the cylinder because the inner valve spring held the center of the retainer. I haven't done a leak-down test yet but at this point it seems that there is no real damage, other then the retainer. But of course the question remained about what caused it to break, so we took off the other spring on the cylinder to look at it's retainer and found out that it was on the verge of failure as well...and at this point I'll assume that the other 14 are in similar shape.

What's happening is that the coil that is placed between the inner and out springs is "chewing" it's way through the retainers. Here's a pic of another retainer I took off the engine;



No here's another pic with the inner coil placed in the groove that shouldn't be there...as you can see they match up perfectly.



I never thought anything like this could happen, I'm guessing that there is only about 15,000 miles on the springs and retainers, but I could be off on that. So now we are in the process of replacing all the springs and retainers, but this time we filed down the leading edges of the coil to try and make sure this doesn't happen again.

Anyone else see anything like this before?

 

Nope, I've never seen that type of failure. But, I have read where some don't think Ti retainers are durable enough for a street engine.

 

That may very well be true! I think with proper prep work on the springs it won't be a problem in the future.

 

My vote is to run out and buy a lottery ticket while you are still
surrounded by the aura.

There appears to be small fragments from the 'machining' performed
by the damper springs. Have you considered cutting open the filter
for inspection?

The oil pump gears would be susceptible to damage from fragments
small enough to pass through the pick-up screen. Larger fragments
may be gathered on the outboard side of the screen.

The rear main bearing receives unfiltered oil from a passage directly
upstream of the pump. Other points in the lubrication circuit receive
filtered oil with the caveat that there is a by-pass valve in the adapter
that the filter threads onto. Under certain cold-start/viscosity/RPM
conditions where the filter is unable to pass sufficient fluid, pressure
is relieved at the by-pass valve, allowing unfiltered oil past the filter.

.

 

Perhaps you can test and confirm it, but my money says that the
Ti retainers are non-magnetic.

Consequently, any fragments that shed are free to roam unhindered by
magnets that might be situated around the valley or bottom end.

.

 

Oh, I know Ti is not magnetic. The metal shavings I'm actually not all that worried about at this point, only because of the time-frame and the amount of metal. After I looked at some receipts, these retainers have closer to 35,000 miles on them. Now, of course I'm not too happy about them at all either though...

I actually had a tear-down for this engine planned for late summer...I may move that date up by a bit!

 

We just finished the leak-down test and that cylinder checks out okay. It's not as perfect as I'd like to see it, but it's well within acceptable limits. So we swapped all the springs and retainers out on the drivers side...should finish up the passenger side tomorrow afternoon.

I'm still in shock at how good the situation has actually been so far, all things considered!

 

I have the same problem. I bought a used set of 113 heads that had Ti retainers. I don't know how many miles are on them. The inner damper coil is starting to cut into the retainer. Mine are not as bad as yours, but the end of the damper coil has begun to cut a groove about 270 degrees around the retainer. I will replace them with steel ones considering my car is a daily driver that will never see the high rpm's normally associated with Ti retainers. The inner damper coils on my heads are razor sharp on the ends and should have been deburred by who ever was in there before.

 

I'm not talking about retainers specifically, but anyone who works with Ti knows in certain circumstances it can fatigue quickly and break.

 

I have heard this too.

 

I personally have never run titanium retainers on any motors I've ever built; so I'm no expert on them. I seem to recall hearing somewhere along the line that they have limited life on a street motor. Are you sure these are the correct retainer for the springs used? It looks like the inner step is much thicker, and would better support the inner spring; if it were wider, or the spring narrower. How about retainer- to-valve guide clearance, or spring compression heigth problems? Also, Comp Cams has a Lightweight Tool Steel retainer that they advertise to be within "2-4 grams of a titanium" retainer; if you feel you really need a lighter unit.

 

They are definitely the correct retainers, I think the main issue was the fact that the middle coil was extremely sharp on the edges, and I'm not sure what kind of metal it's made out of but it took a couple hours to break the edges properly on the new set of springs (same ones as the ones I just took off).

I'll keep an eye on them for a while and see of rounding off the edges of those springs helped or not. If I see the same type of wear then I'll just switch over to steel retainers. I don't need the titanium ones, but they are better for higher revving motors, but my 7200 RPM rev-limit doesn't really require them.

I guess for now, anyone who has Ti retainers with some healthy springs might want to consider taking a look at them sometime!

 

What kind of cam are you running? rocker arms? I would think that would make a difference.

 

I've never seen or heard of this before. It looks like it might do that if the spring was "stacking" or something. Good luck and let us know the outcome.

 

I had a similar problem with anodized aluminum retainers on a race MG engine. Fortunately I had an oil filter that I could open and inspect the screen to see what was in the oil. The specs of aluminum in the filter lead me to the valve retainers. The problem is that any aluminum or titanium is not as hard as the steel spring. The spring should be milled flat to maximize the contact area with the bottom of the retainer. If not you have a steel chisel working a softer material. The result in inevitable.

Larry

 

I have heard of this happening before. A friend of mine had a valve drop in his Acrua a few years back. The head had been rebuilt and contained TI Crower retainers. Retainer split very much like yours and dropped a valve. Catastrophic damage inside, and a new motor later, the car was sold. If I am not mistaken, he tried to get Crower to reimburse him for the damages. I do not know the outcome.

 

 

As I mentioned earlier, I've never used them, nor have I known anyone who did on the street. I have seen aluminum retainers break, and I've heard of some breaking titanium Keys. I've also heard that they (TI) handle Beehive springs better than 2-3 pc; distributes the load and less harmonics. But again, that's on low mileage race motors. Vetracr may have something there, with milling them flat, or your cleaning them up. I don't know if I'd chance it myself for the extra 2-300 RPM. JMHO. Good luck

 

Yeah, I was lucky that the inner spring kept the valve from being dumped into the engine!

I'm hoping that grinding down that middle coil will help things. However, I will be pulling a couple of them back off in a month or so to see if they show any signs of repeating this. If so then I'll switch over to some lightened steel retainers and be done with it.

 

I ran a set of Ti retainers from CNC Cylinder Heads using double springs for a 'mild' hydraulic roller cam...not much more than a few thousand street miles.

I experienced similar 'wear' from the damper between the springs, but definitely not to the same degree.

Speaking with my machine shop (primarily off road engines), they stated that Ti retainers are throw aways...ie. should be replaced routinely. It is a softer metal so made sense. I switched to the beehive springs with the appropriate smaller retainers out of non-Ti materials.

Solved my valvetrain crash at 6200 rpm (along with an AFR Hydra rev kit).