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Thoughts and theories very much appreciated Guys, I've been doing this along time and this is new to me : Heres the scenario Fresh BBC motor has approx two hours on it starts to miss starts runs , good OP and has a miss and slight "tick" . 7 cyls have 150 compression, #2 cyl "0" , Josh started to pull the intake and heads found the first piece (pic1 and 1a ) in the oil return area at the rear of the R head found the lifter ball at the front oil return area (r side) The second picture is the base of the anti pump up lifter still in the bore as viewed in a small mirror The affected lobe (#2 exaust) is gouged from running on the damaged lifter but not flat , #2 exaust valve is bent and theres a very small ex valve "kiss" on #2 piston dome The CM pushrod is good and the Roller rocker is fine It looks like the bottom of the lifter simply "blew out? :mad: Thanks in advance Tom
PIC 1

PIC 1 A

Base of #2 exaust lifter still in the bore
 

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I have the same lifter from my buds boat..............


The only thing I can give you is it was involved in a major overrev (ours), he didn't have a tattle tale tach, but I'm guessing 8,000 RPM for about a second, floated the valves really really hard and was missing when it restarted cracked the cam and blew the hardfaced area of the lifter off...Broke it right at the oiling groove...

The machinist thought it was a loose lifter bore until I told him about the dumbass move with the water ski (long story, involved a foot throttle, too much sh!t in the bow and showing off...):|err

Chinese lifters? :)bulb

GT :)hand
 

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steelcomp was here
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Crap parts. Straub is out of town...we can blame him for a few days.;)
 

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Scott honestly as hard as we want a plausible explanation/underlying cause I'm staring to lean towards a simple part failure ? What else causes a lifter bottom to "blow out" ?Tom
I have seen this before and found that the valve hung in the guide thus letting the lifter float freely until the cam beat the lifter into submission. qwik verify is to check the valve and guide for galling and or hot spots. depending on rpm, this all happens way to fast! M
 

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steelcomp was here
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I have seen this before and found that the valve hung in the guide thus letting the lifter float freely until the cam beat the lifter into submission. qwik verify is to check the valve and guide for galling and or hot spots. depending on rpm, this all happens way to fast! M
I think you PM'd me about something like this a while back didn't you? Never really didn get to the bottom of it, but in response to what you said above, I've seen the bottoms of lifters so beat up they wouldn't come out of the bore, but they were still in one piece. It looks to me like this was just plain ol' parts failure.
 

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steelcomp was here
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Scott honestly as hard as we want a plausible explanation/underlying cause I'm staring to lean towards a simple part failure ? What else causes a lifter bottom to "blow out" ?Tom
That would be my guess, looking at the falure. Looks like a pretty clean fracture around the bottom of the lifter, Almost like where the heat treat stopped...
 

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Discussion Starter #10
I have seen this before and found that the valve hung in the guide thus letting the lifter float freely until the cam beat the lifter into submission. qwik verify is to check the valve and guide for galling and or hot spots. depending on rpm, this all happens way to fast! M
This is kinda what we thought (to some degree) at first but there no obvious 'trauma" to the valve stem or guide ? I'll get closeups of those tommorow , stumped otherwize
 

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steelcomp was here
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The only thing I could see as a "failure" of some kind would be for the lifter to hang up in it's bore at max lift long enough for the piston to hit the valve causing it to hammer back on the lifter's internals and blowing the bottom out that way. Does the broken lifter move freely in the bore?
 

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I think you PM'd me about something like this a while back didn't you? Never really didn get to the bottom of it, but in response to what you said above, I've seen the bottoms of lifters so beat up they wouldn't come out of the bore, but they were still in one piece. It looks to me like this was just plain ol' parts failure.
Steel, yes I did P.M. you awhile back about simular situation. I have been off this thread for quite awhile and will now tell you what I found on my ordeal. After talking with my cam supplier I learned that a bad batch of lifters that had a ring cut into them were coming apart at that oil groove. But my lifters were not that style. Jetboats are so parts failure could be the case here. Stuck valve was the culprit in my senario. So now that jetboat responded back as to a negative on valve stick I would lean towards lifter failure and replace the whole set with a solid body style. M
 

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steelcomp was here
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Steel, yes I did P.M. you awhile back about simular situation. I have been off this thread for quite awhile and will now tell you what I found on my ordeal. After talking with my cam supplier I learned that a bad batch of lifters that had a ring cut into them were coming apart at that oil groove. But my lifters were not that style. Jetboats are so parts failure could be the case here. Stuck valve was the culprit in my senario. So now that jetboat responded back as to a negative on valve stick I would lean towards lifter failure and replace the whole set with a solid body style. M
Ahhh, OK...so ther was a groove around the bottotm of the lifter. I thought so...definitely a stress riser asking to fail. Might as well be a perforation labeled "Break Here"...
 

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Ahhh, OK...so ther was a groove around the bottotm of the lifter. I thought so...definitely a stress riser asking to fail. Might as well be a perforation labeled "Break Here"...
Got me laughing on that one steel!!! The reason I felt that there might be another reason for failure and the lifter getting beat to death is if you look at the lifter in the mirror picture you will notice that the retainer clip for the inner portion of the lifter is missing! Super lose valve adjust can cause this but it just looks like it could be other factors also!!!! One thing for sure is I would drop the "break here" style lifters and make sure that all else is free moving and no chance of sticking or binding. M
 

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comp

I've had 2 solid roller sets fail from comp , heard from a pretty reputable source they out source there lifters on many, and use various sources of import metal
I'm done with them
 

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I've had 2 solid roller sets fail from comp , heard from a pretty reputable source they out source there lifters on many, and use various sources of import metal
I'm done with them
FWIW most cam companies out source lifters. There is alot involved in manufacturing a lifter and the process is costly unless you are a mass producer.
 

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Got me laughing on that one steel!!! The reason I felt that there might be another reason for failure and the lifter getting beat to death is if you look at the lifter in the mirror picture you will notice that the retainer clip for the inner portion of the lifter is missing! Super lose valve adjust can cause this but it just looks like it could be other factors also!!!! One thing for sure is I would drop the "break here" style lifters and make sure that all else is free moving and no chance of sticking or binding. M
Don't forget theres was a quarter inch of lash :pwith the the bottom of the lifter missing, i'm think the retainer clip got beat off the lifter secondarily.


The only thing I could see as a "failure" of some kind would be for the lifter to hang up in it's bore at max lift long enough for the piston to hit the valve causing it to hammer back on the lifter's internals and blowing the bottom out that way. Does the broken lifter move freely in the bore?
I was kinda think along those lines, the cracked side of the base looks like it was rubbing against the maiting side for a few.

Whats left of the lifter moves, till the "new"' base trys to go up through the bore.
 

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I have a theory.... Does this dealio have a cam button?

How does the cam gear thrust surface look?

A severe cam walk could cause similar problems pushing on only part of the tappets flat surface and loading it funny (not funny ha ha, funny queer :)gay:()...Just thinking outloud...

GT :)hand
 

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steelcomp was here
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I have a theory.... Does this dealio have a cam button?

How does the cam gear thrust surface look?

A severe cam walk could cause similar problems pushing on only part of the tappets flat surface and loading it funny (not funny ha ha, funny queer :)gay:()...Just thinking outloud...

GT :)hand
Flat tappets typically don't walk much, but it's not unheard of. I think I'm stickin with the "crap parts" theory. :)st
 
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