johnnyboy

iTrader: (3)

how can i tell if i have a collapsed lifter? i just did a head and intake swap with an lt1 cam on my lo3, when i put the cam in i couldn't get any of the lifters to come out easily so i just pulled them up until they didn't move and then installed the cam and pushed them back down. now after setting valve lash the engine runs smooth except for some kind of a knocking kind of noise. after pulling off the valve covers again i noticed that one rocker isn't moving anymore. a friend suggested a collapsed lifter is that what this sounds like? if so i have a set of lifters from another motor that are in pretty decent shape, would it be okay to reuse them?

84z28350

It is OK to re-use roller lifters. flat tappet is a whole different story, since they wear and 'seat' on the cam you HAVE to replace them when you change cams or you could end up wiping a lobe off the cam!

sofakingdom

iTrader: (1)

There's no such thing as a "collapsed lifter". Lifters don't "collapse". That's a hot-rodder myth for "I can't figure out what's REALLY wrong with my valve train".

In any case, the internals of the lifter have about .100" of total travel, and the cam should be moving the whole thing about 3 times that far. So if you have one that's not moving AT ALL, as opposed to one that doesn't move QUITE ENOUGH, you've got something seriously wrong.... something along the lines of a missing cam lobe.

Easiest way for that to happen in the factory roller system, is for the dog bone to come off of the lifter, and the lifter to turn in the bore; in which case, immediate and total destruction of the cam and lifter is the guaranteed result. Let's hope it's not that.

What happens when you adjust them properly? Are all the rocker nuts at about the same height on the studs?

johnnyboy

iTrader: (3)

well i pulled all of the lifters yesterday and they were all fine but i put in the other set i had, they were newer anyway. the cam looked fineand all of the rockers move as they should but it still sounds the same. and yes all of the nuts are at about the same height. i pulled the serp belt and ran it to see if maybe it was an accessory that was bad but it still makes the noise. i'm stumped, could i have knicked a bearing when i installed the lt1 cam? i think i'm going to have to just take the car to my mechanic and have him look at it.

sofakingdom

iTrader: (1)

No... well, you could have, but that wouldn't make a noise...

About all that you are likely to accomplish by doing that, is if the noise is caused by excessive car weight; and he lightens the car, with all weight savings concentrated in the immediate area of the driver's wallet. If reducing your wallet's weight doesn't seem like a good way to fix the problem, then that is probably not the best course of action.

If it's ONE valve that's clattering, a great place to start, would be by figuring out which one it is. Pop the valve covers off and start the motor; get a piece of heater hose and stick it in your ear (I LOVE telling people to do that!!!!) and listen for where the noise is coming from. If you can't pinpoint it like that, try backing off the rockers one at a time until the offender is found. It's alot easier to troubleshoot ONE thing, than 16 identical ones that you don't know which one is farkled.

johnnyboy

iTrader: (3)

i didn't mean to have him work on it, i can just have him diagnose the problem and give me his opinion. he'll usually do it free of charge i hope its not a valve because i just bought these heads, to avoid having to rebuild my old heads, although they were used heads so what can you expect? the stethoscope idea is a good one. i'll do that this weekend. if it is just a tapping valve how would i go about fixing that?

sofakingdom

iTrader: (1)

Think about what you just said for a second.

Now.... Just exactly how is he going to do that?

Trying to "diagnose" that sort of problem without actually working on it, is about like the Arabic custom wherein a male doctor is forbidden to enter a female patient's tent, even to examine her; so he must make his diagnosis from outside the tent. Now THAT'S bound to be real effective.

Problems that occur as a result of modding a car are like this. They usually stem from something done wrong, or a factory tolerance being exceeded, or some part that had an imperfection that didn't matter before but now is exposed, or something like that. Your situation isn't something like he can just hook up a code scanner and it says "#6 injector flow rate low" or something like that. The ONLY way to find your problem, short of either pure dumb luck or just noticing something obvious that you've overlooked, is to take it apart and inspect every piece.

Taking broken cars to the "mechanic" has its time and place. This isn't one of them. About the way that taking a car with an aftermarket cam to the dealer and complaining about driveability, is a great way to just throw away money, for alot of the same reasons. They'll tell you yeah, it drives terrible, runs like crap; the codes say such and such; we replaced the O2 sensor, the PROM, the ECM, the ...... and your eyes glaze over as you look at the bill for thousands of dollars worth of work that the car didn't really need (which is what you authorized when you signed a work order that says "diagnose and repair", and your debt to them will hold up in court at full face value); and when you get back in the car, it's EXACTLY like it was before.

Do the heater hose thing. It's alot cheaper, and probably take less time and trouble than opening that other can of worms.

As far as fixing a tapping valve, that would depend on exactly why it's tapping; i.e. what's making it tap.

johnnyboy

iTrader: (3)

i understand what you're saying about the whole mechanic thing, but he's a friend of the family and won't charge anything unless i have him replace parts or actually fix anything.i would rather do things myself though, so i will keep looking into the problem to see if i can figure it out

Tonysz383

Did you replace the cam? Is it a roller or flat tapper?

five7kid

iTrader: (14)

Sounds like roller lifter, with a different cam put in.
You already know one rocker isn't moving. The reasons I can think of for that would be: Improperly adjusted; rocker stud pulled out; lifter and/or cam lobe wiped out. Since the lifters were stuck in the block in the first place, improper adjustment is pretty likely. Rocker studs pulling out isn't all that uncommon. Not getting things back together properly is a good way to wipe out a lifter and/or lobe, and since the engine was apparently gunked up enough to stick the lifters, the lifters themselves may not be in that great of shape. With roller lifters, cleaning and inspection is prerequisite to reuse (and it's okay to reuse them if they look good).

sofakingdom

iTrader: (1)

The valve that's "not moving": how are you adjusting its rocker if it's not moving? Is it stuck open or closed?

It's not impossible, especially if the heads got some old used stock springs stuck off onto them when they were "rebuuilt", is that the new cam which pushes the lifters up farther than the old one, has forced one of them up to a point that its varnish is making it stick; and its old worn-out used stock valve spring might not be able to generate enough force to push it back down.

Just a thought.

If the engine is varnished up severely enough inside that lifter varnish can overcome the valve springs, it's a candidate for the ATF treatment. Since it's got all new oil now, replace the filter; and put a quart of ATF in the new filter before you put it on. It's SUPER high detergent, since as we all know, just a little bit of funk in a transmission will screw it up. It will eat the crud out of the engine and suspend it in the oil where it can be drained. Keep an eye on the oil; it will probably turn black and thick within a few hundred miles, which is of course all the crud being dissolved. Once it gets funky enough to look like it usually does when it needs changing, go ahead and change it, and include a quart of ATF in the new oil as well. Keep ATF in the oil until it quits coming out black and gooey.

And of course, if lifter varnish can overcome the valve springs, that's a sure sign too, that the springs are BEYOND INADEQUATE. Get them out of there ASAP, and replace them with some one of the top-line cam mfr's entry-level ones; Comp 981, Crane 99846, or the equivalent from Lunati, Crower, or Isky. NOT GM or K-Motion. Replace the retainers and keepers with the recommended companion parts from the same mfr, throw away the stock "rotators" if they're still there, buy an assortment of shims such as Comp sells, and set the installed height as close as practical to 1.700".

Again, just a thought, something to check on. Sounds like regardless though, you need to do the ATF thing.

johnnyboy

iTrader: (3)

i put an lt1 cam in, so it's a roller i put a set of 305 vortec heads on along with a cam from a '95 lt1 so as far as i'm aware the lift on the cam is a decent match for the springs on the vortecs, i haven't been driving the car because it's making this noise and i have another p.o.s. that i can drive while i'm figuring this out, do you think it would be okay to drive it like this? and i never heard about the atf thing i'll have to do that too. good idea! and i pulled all of the old lifters and put the other set in, none of the old lifters seemed to be damaged in any way and the cam is fine, maybe the one rocker not moving was just my imagination, it was kind of dark.

Chevyguy496

Just a thought but did you check the spring and guide clearances? Stock Vortec heads are pretty limited on lift. Not sure how big the cam you put in is but you might have a clearance problem. I had to have mine cut to run the cam i wanted. My vortecs are off a 350 though and they have different port sizes than the 305 ones so I dunno what other differences there are.

johnnyboy

iTrader: (3)

no there shouldn't be any clearance issues, it's not like everything is making noise, just one thing