need one lifter...

Hey guys I found one bad lifter in my firebird, its got the original LT1 style lifters in it, I just want to replace just that lifter as all the rest look beautiful. My question is: can I replace just that one with an ls7 lifter (current specified factory replacement for lt1) or do I need to track down an original lt1 lifter?

Car is going to get a cam if that makes any difference...

orrr maybe it'd be better to get a whole new set? I dont really know what to say here cause the factory ones look so good but they have ~130k miles on them... what do you guys think?

I would say new cam new lifters but you could just replace 1 if you want

new cam new lifters. yolo

personally, if i was that far in it thats what i would do, but otherwise, i have plenty of stock lifters if you need one

Not a big deal with roller lifters like it is on flat tappets. But if you've got the scratch, might as well buy a whole set

If you've got the money and you're that deep into the engine already, I'd say replace them all. Especially since you had one fail.

Roll the lifter wheel against the inside of your wrist on the sensitive skin. This skin is soft and you can feel if the wheel is catching. Check the surface very closely. If all is good you can reuse the old ones.

The best way to kill a lifter is to run the engine against the rev limiter during a burnout. It can mushroom the lifters out a bit at the roller end.

Thanks guys, I think i'll order a set of ls7's
@noice I'm pretty sure it was over revved somehow and it screwed it up good lol. The lifter took the beating, pushrods, rockers, and springs are all ok/straight.

the guy I bought the car from said he was racing a honda and he was way ahead of it then it started knocking and locked up... needless to say he didn't win:jest:

Attachment 30173Attachment 30174

Why is the "dog bone" above the spider in that pic? If that's how it was when you pulled the intake that's what killed the lifter and your cam is probably shot too!

https://www.youtube.com/watch?v=5NnMuyifPA4

If you want to see how bad things are when you bounce off of the limiter, look at what happens in the belt tension pulley at the starting line. Before you say, that is just the belt stretching, rubber belts are used in place of timing chains. There is very little stretch.

When the engine is under load, the cranshaft is twisting, the front of the crankshaft doesn't twist much but the rear most part of the crank twists the most as all the torque must flow through it to get to the rear of the of the engine. When you rev limit the engine, the crank unloads and untwists until the limiter allows the engine to rev again and it twists up again.

This kind of motion is god awful on things, but it is REALLY bad on the valve train. It makes valve retainers/keepers hard to knock out, bends pushrods, floats lifters. All sorts of bad shit.

This is why running an automatic with a transbrake is awesome, you can rev limit the engine at the line at low RPMs, like 3K.

Quote:

---

Originally Posted by 96LT1355Z28

Why is the "dog bone" above the spider in that pic? If that's how it was when you pulled the intake that's what killed the lifter and your cam is probably shot too!

---

You know I asked myself that same question when i pulled the intake :shiner:. Surprisingly enough the lifter that is still in the bore with the pushrod still in the cup was the bad one. And my guess is the guy hit the limiter at higher rpm and cause this, then proceeded lockup his engine.
@noice thats a cool video, I personally avoid the limiter at all costs lol

Deffinatly check that cam lobe, those retainers (dog bones) are what keep the rollers in line on the cam. Without it the roller can turn sideways which will ruin a lobe/cam in no time!

is that pic in post #7 the bottom of the lifter that sets on the lobe?

It is kinda blurry there and a lil hard for to fully understand what I am seeing in the pic.

If it is the bottom of lifter that rids on the lobe, that cam is TOAST!!!

Look down that lifter bore and look at the lobe.

Lloyd

@NightTrain66 yes thats exactly what your looking at. I had trouble getting my phone to take a good picture of it for some reason... yea that lifter is straight fubarred and most likely the cam, I'm gonna pull that cam and maybe i can make a lamp out of it or something :)

The LS7 lifter set is #12499225, can be had for around $100. Definitely worth switching them all out while you're in there, especially if you're going with a more aggressive cam.

Ls7 lifters have had way too many failures to give me any kind of warm and fuzzy, I'd either source a high mile cheap maybe rid knock lt1 off Craigslist and rob those lifters and cam and part out the rest. Might be able to come out with a profit and a running motor.

I just remembered that I have a set of lifters sitting by the camaro, I'll have to go inspect them and see what they look like but iirc they weren't bad lookin... I swear some weeks my brain just shuts down, must be a blonde thing?

have you pulled the cam yet?

Lloyd

Quote:

---

Originally Posted by NightTrain66

have you pulled the cam yet?

Lloyd

---

@NightTrain66 this is the cam. Second one over from the journal has the damage.
Attachment 30338

yea, that's what i was expecting.

Lloyd