Elephant Foot on Rockers: how tell if worn out?

911 tweaks · 01-05-2009, 01:00 PM

Does any one know how to tell if the elephant foot is worn out on rockers?
I believe you have to buy the foot & threaded shaft as 1 unit and cannot buy just the feet OR it is safer to buy the foot/shaft as a unit as it may be a factory press fit?

To determine if the "foot" is worn out or soon to be, is their a way to determine? Possibly measure the height, possibly, or is it best to just replace the assembley?

Thanks, Bob

Henry Schmidt · Henry Schmidt's Garage

We replace them as a general rule.
Rebush, surface and new adjusters are just part of the job.
I will say that if the engine is a freshen up on a limited hour race engine the adjuster is reused unless there is a valve failure and at that time the adjuster is replaced as a rule.

OldTee · 01-05-2009, 05:27 PM

What about rocker shafts? When to replace?

Henry Schmidt · Henry Schmidt's Garage

The shafts are less critical than the rocker bushings.
We polish all rockers shafts and check for grooves. Any grooved shafts are trashed. Any rocker that is more than .0015" undersized are trashed .
It is important to check expansion joints for cracks. We also plate the wedge caps which add size to compensate for slight anomalies in cam towers.

911 tweaks · 01-05-2009, 06:08 PM

if one was to have an unknown mileage set of rockers or a blown up engine which always have metal pcs flying around them PRIOR to the big ka-boom, I agree to remove doubt to throw away the elephant foot & threaded shaft. However, if on a tight budget, is there a spec to check?

You know what, the more I think about this part when it is in use - it is in constant contact chasing the cam profile - and it would be the nuts to lose a foot off of its threaded shaft all in the name of saving $20/rocker... but the frugel side of me still begs to ask if a wear limit ~ spec exists?

Thanks Henry for your above info & if you can add anything further to this subject...
Bob

304065 · 01-06-2009, 05:28 AM

I am not aware of any specification for wear in the factory literature. I would say its more likely that the end with the screwdriver slot has been buggered or the threads stripped by some DPO than the elephant foot wearing out. I replaced all of mine at the rebuild.

Henry Schmidt · Henry Schmidt's Garage

Quote:

Originally Posted by john_cramer

.....edit....... I would say its more likely that the end with the screwdriver slot has been buggered or the threads stripped by some DPO than the elephant foot wearing out......edit.....

I would say that with a high mileage engine you will likely see worn out adjuster tips.
I took three random elephant feet from our box of discards and one new tip and set up this simple method for measuring them.
Our findings were:
# 1= .009 " of play
# 2= .017" play
# 3= .007
New one showed less than .001" play. New or used ? You make the call.

911 tweaks · 01-06-2009, 11:15 AM

Thanks Henry... amazing that amount of play/wear... I ordered some new adjusters and was going to do some sort of measurement test but you beat me to the punch... again...
I thank you sir for your efforts and 1 more element of engine analysis understood.
Your the best Henry !!
Bob

88911coupe · 01-06-2009, 02:57 PM

crap...one more thing for me to worry about on my rebuild...I used the old ones.

930gt-40r · 930gt-40r's Garage

Now how do these really fail? Every time I have blown the rockers off or seen another car that bent the valves etc the feet are unharmed. I have never reused them but I am wondering how they would fail because the feet are kind of sandwiched between the valve stem and the adjuster.

T77911S · 02-26-2009, 08:52 AM

i have been curious about this for a while now. i did a valve adjustment a while back, the first time, i started it up and it sound GREAT for about 2 minutes, then i started hearing valves tapping. long story short, i ended up doing it 3 times i think until i could get them some what quiet. BTW, i adjust them so the .004 is very very snug, i have even done the back side meathod. while doing them, it seemed like some would be set correct, then i would go back and recheck them and the feeler would not go in, so i would loosen it up enough to get the feeler in, then it would be too loose, when i got it adjusted right, the screw slot was back at the same angle it was when all this started. if your still with me, here is my point, i think the inside of the foot wears a groove in there, and when i am putting the feeler in and out, it turns the foot so it is in and out of the groove thus changing the clearance, so yes, i would replace the adjusters if for nothing else to save headaches doing valve adjustments. this is just my theory of what is happening to me. i would be curious if henry could check a few more, this time turning the foot to see if the wear changes.

vmisquez · 02-26-2009, 09:45 AM

My old set had 120K miles on turbo motor. I bought new ones so I could hear a blueprinted and balanced motor idle WITHOUT any disheartening noise from worn adjusters.

It would be a shame to go through all of this work and cash otherwise.

I'm building a turbo 3.5L stroker with EFI. Ill post pics and specs at a later date

T77911S · 02-27-2009, 03:01 AM

just looked them up. those little SOB's are $20! X 12=$240!!!

T77911S · 02-27-2009, 03:38 AM

just found them on another site for $4, much better, unless it is a mistake

Flat6pac · 03-01-2009, 04:25 PM

If you properly adjust your valves, any wear in the elephant foot would be part of the valve lash. After the adjustment screw is locked, it wouldnt make any difference where the .10mm is coming from, its at the valve...my thought
Bruce

930gt-40r · 930gt-40r's Garage

Quote:

Originally Posted by Flat6pac

If you properly adjust your valves, any wear in the elephant foot would be part of the valve lash. After the adjustment screw is locked, it wouldnt make any difference where the .10mm is coming from, its at the valve...my thought
Bruce

Now this is my school of thought- agreed

T77911S · 03-02-2009, 10:20 AM

Quote:

Originally Posted by Flat6pac

If you properly adjust your valves, any wear in the elephant foot would be part of the valve lash. After the adjustment screw is locked, it wouldnt make any difference where the .10mm is coming from, its at the valve...my thought
Bruce

i checked 2 that i had laying around. both checked about .008. i am now curious as to how long it takes to wear a new one to .008? it may not be worth it to replace, think of the valve adjustments needed to break in new adjusters.
anyone ever have any break?
the ones i checked had about 130k, so iam told.
my concen with them was were they causing me to missadjust the valves. sometimes it felt like the foot would tilt making it hard to get the feeler in.
the motor comes out this weekend, i will go through them again