UPDATE POST 58, UPDATE POST 29 randomly got sewing machine
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
maybe i could pull another rocker and measure the thickness of the stem vs the space inside the cap....maybe it was too loose moving around? dont remember there being much play tho. anybody know how much larger your lash cap should be vs valve stem width?
Another thing that comes to mind is a collapsed lifter. Thinking it may be possible that the extra lash created by a loose lifter/pushrod/rocker asssembly may have beat the cap up and caused the failure. I’m really just brainstorming ideas here, I don’t have any first hand experience with lash cap failures. But the CSI part of it is kinda fun.
If a cap spins on a ti valve the valve will wear. It isnt likely it happens but it does every once in a while. That is the more likely scenario. Those manley caps are very very strong. Not likely it broke in half.
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
ok so how do you prevent it from spinning lol. and any idea what tolerance the lash cap should be oversized to the valve stem.
Ive hardly seen any spin but it is a possibility. Esp with used valves used in nascar. There is a reason they replace parts so often. Most of the time they are just ran without a second thought.
I do not know the clearance. Manley would be best to ask there or Del West.
I do not know the clearance. Manley would be best to ask there or Del West.
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
not sure whats going wrong. i click on reply, manage attachments, then from albums, drag them into the box, they appear and everything. i hit upload. the window closes and im left with a blank white slate. i click manage attachments again, and they are gone.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
https://ls1tech.com/g/album/11538781
could only get them to load in albums. description under each pic
could only get them to load in albums. description under each pic
The witness marks suggest the rocker tip may not have been centered on the valve cap. If that’s the case, edge loading the caps could cause the caps to rock and lead to damage. I’ve never seen what that type of failure looks like but it makes sense in theory. And your pics seem to point in that direction as well.
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
The witness marks suggest the rocker tip may not have been centered on the valve cap. If that’s the case, edge loading the caps could cause the caps to rock and lead to damage. I’ve never seen what that type of failure looks like but it makes sense in theory. And your pics seem to point in that direction as well.
1)from what i have read, stock rockers are god awful geometry. however, running a longer valve with a lash cap helps make it better. does making it better mean it was good? no. but in theory, i should have been making it better not worse (but as mentioned, that one valve kinda says something wasnt quite right)
2)even if it was side loading and rocked it off, how come it made it 3000 miles? in my head trying to watch a valve in action, i cant see how it possibly could side load it enough to tip the cap off, unless at some point in the rotation the rocker basically was sliding off the cap. also to expand, i have read that another benefit of lash caps is that they essentially make the valve contact area larger, which i would guess is helpful in the fact that your rocker tip now isn't as close to the edge, even tho it really doesnt change its location on the valve. idk tho, but i also am no engine builder so not putting that to rest.
how do i tell if a lifter collapsed? i tried googling it and got bullshit
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
The witness marks suggest the rocker tip may not have been centered on the valve cap. If that’s the case, edge loading the caps could cause the caps to rock and lead to damage. I’ve never seen what that type of failure looks like but it makes sense in theory. And your pics seem to point in that direction as well.
Dont dive too far down the rabbit hole.
Check what you can and move on is my .02. if you are going to tear down you an physically check the lifters outside the engine and see. if a lifter is collapsed it normally wont spring back to std position after unloaded.
Sometimes the lock wont seat exactly right also and keep the cap up and it can pop off also.
Too many questions not enough answers youll see.
Check what you can and move on is my .02. if you are going to tear down you an physically check the lifters outside the engine and see. if a lifter is collapsed it normally wont spring back to std position after unloaded.
Sometimes the lock wont seat exactly right also and keep the cap up and it can pop off also.
Too many questions not enough answers youll see.
You’ll find the lash cap in the engine somewhere when you part it out. If not, it was missed. When (if) you find it, you’ll be able to figure out at that point what happened. Lash caps are used often by builders to improve wipe patterns, regardless of valve material. Gives the rocker more area to sweep across. Ls Oem rocker geometry is hit or miss at best.
The lash cap is probably stuck to your drain plug magnet. I broke 8 valve spring tips on stock LS1 valve springs about 8 years ago, all the tips ended up in the pan stuck to the drain plug.
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
Thread Starter
Joined: Mar 2011
Posts: 3,699
Likes: 168
From: Wilmington, DE
so i found the lash cap. it was there when i put the valve covers on, just like i thought it was. when i pulled the heads i found the cap inside my lifter tray. looked identical to all the others, with paint worn off in all the same spots so it was on there for some time. no knicks or any weird marks, identical to the others. who knows how it fell off, but at one point it was on the valve.
Interesting find for sure. I was expecting it to be in pieces or possibly with marks indicating what could have happened. This probably leaves more questions unanswered than anything but hey, at least you found it.
.....was almost hoping i didn't put it on because i like the thought of running them