It started off with a tapping noise on our 2000 ss m6.
A little back ground..
DD been to track 5 or 6 times ran 11:80s
changed cam to a hydrolic TR 230/224 about 2yrs ago with bee hive springs
cnc heads (last year) changed to patriot gold springs (was told hard to get the bee hive springs or problems with them??)
chrome moly push rods (standard length)
using factory roller rockers
and factory roller lifters
about 83k miles

Pulled engine out to do freshen up and find tapping noise. We found that rollers on lifters were pited really bad to the point it was coming off. Cam lobes scarred badley. (will be ordering a new cam same specs).
Push rods were not bent. Bottom of engine fine (thank god!!)
Question is has any one else had this kind of lifter problem if so what to do, maybe different springs (are bee hive still availible?) or different lifters...
Would apprieciate any help we could get.

 

I am having trouble with LS7s right now. Didn't last 250 miles during break in??? Still need to take them out to see how bad my MS3 is.

 

I would suspect valve train issues first, lifters/cam issues second. Lofting the lifters and poor control will cause this problem, so make sure you are looking at the problem and not the symptom of the problem.

 

Sounds like improper preload to me. What length pushrods did you use, and were your heads milled? What head gaskets (thickness) did you use?

 

Im having problems with my LS7 lifters, I had to buy a whole new set because I have at least 1 bad one. Preload has been checked, rechecked, and rechecked x10(no joke).

Ordered a new set of lifters and a new head gasket so I can replace all thelifters on the drivers side(pretty sure that the side its coming from).

I just hope my cam isnt screwed up at all. Building a nitrous shortblock soon and will definately not be using LS7s again.

 

When hubby ordered new cam talked with Thunder Racing about problem and they suggested checking the plastic trays that help hold the lifters in place.
Sure enuff the plastic showed wear..
Has any one else heard or had this problem?

 

I put in a set of LS7 lifters about a year ago, have over 20k miles on them and no problems (knock on wood). I replaced the plastic lifter trays when I installed mine. For springs I went with PAC 1218's.

 

A friend of mine had the same problem in his trans am. The lifter would not come out of the top after we pulled the heads off. We had to pull it from the camshaft hole with a magnet. Come to find out the roller shaft pulled out and roller and cam were beat up bad. We called Thunder and asked them about the springs that were on the heads which at the time were manley's and they said that with the ramp rate of their cam those springs are gone and they recommended patriot golds. We replaced the lifters cam and springs and it is good as new. As far as to what caused the problem I guess it was just pushing a factory part too far for too long.

 

Yes. For the few bucks they cost I always change them.

 

Unless the trays were cracked I don't see them as being the cause of your problems. Can answer the questions I posted earlier, it would help rule out some potential causes...

 

Chrome moly pushrods same length as stock ones, no heads not milled and head gasket was reordered from dealer.

 

Unless they have a "10" on the bottom of them. Some marked with a "10" had a slight angle to them so the roller wasn't running in the correct direction. Something else you may want to check.

 

The old trays have 3 and 4 on them, we ordered new ones and I was wondering if they still sent out trays that have the 10 on them? Hope not.
Just had gaskets etc come in another $400, ordered the cam and rod bolts, new lifters, having crank done, heads sent out to be checked and we havent even got started good yet on the rebuild... I know, I know preaching to the choir but the faster the toy the more money it cost to get it goen again as yall already know.

 

Last set of trays (LS1) I ordered the lowest number was 17. GM and Katech are aware of the issue, it was found I believe by David Farmer who used to drive the C5R. He had similar issues with lifters/cam.