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getmygoat · 08-25-2007, 08:03 PM

Hi all,

I rebuilt my 400 about a year ago, its got about 1,000 miles on it. Crower 60916 cam with #12 heads, about 9.4 compression.

Coming back from the repair shop today (ironic) at freeway speeds - about 80 MPH for 30 miles.... When I come off the freeway I notice a pretty significant ticking coming from the old pontiac mill.

Get home, pop the hood... Yup - she's clacking pretty good. Put the automotive stethescope on it... sounds like its coming from the number 8 position.

Just pulled the A/C and valve cover.. that last rocker on the passenger side (#8) is very loose... so loose you can see daylight between the valve stem and rocker when I hold back the rocker.

I loosened up the hold down nut (it was tight) and pulled the pushrod... It appears fine.

Sounds like a lifter or more likely the cam?

Fred

p.s. - I broke the engine in before I heard about the zinc issue.... (Literally the day before). Next day I added STP, then changed the oil and added eos... Have been running EOS since first start + 30 minutes.

Billy177 · 08-26-2007, 12:10 PM

what did they fix at the shop, not sure if your heads have press in or screw in studs but if press in make sure one did not pull out.

AllRise · 08-26-2007, 12:39 PM

Id say replace the lifter, and then check the lift with a dial indicator. If you have one.

getmygoat · 08-26-2007, 12:41 PM

The shop fixed stuff unrelated to the engine.

I'm pretty sure #12's have screw in studs.

I just cut open the oil filter from the last oil change... no metal

I guess I'll cut open the current oil filter and see what I see.

WARPed · 08-26-2007, 12:51 PM

Yes #12's have screw in studs

getmygoat · 08-26-2007, 02:53 PM

Well, I cut open the last two oil filters for the engine.

I know people say these will be full of metal if a cam goes bad, but I'm not sure how obvious this would be?

Of course, when you cut open the filter, you put metal filings in the filter.... but I don't see anything obvious in these filters.

Its interesting to see how much more densely packed the napa filter is compared to the fram.

Allrise - Can I replace the lifter without pulling the intake/valley pan? (Through the pushrod hole somehow? - If I have to pull the intake/valley anyway, that will be a good chance to look at the cam directly I guess.

The other point is that while this one rocker is real bad, some of the other rockers are slightly loose.. i.e. I can move them a little bit such that I hear metal to metal contact. - So that makes me think I either need to replace all the lifters or the cam is going bad on multiple lobes but this one is the first to fail.

67drake · 03:10 PM

Thats why I have not used Fram in 20 years. NAPA on all 5 of my rides right now.Not saying that would have saved your cam.Just nice to see the difference on the insides of those.

b-man · 08-26-2007, 03:05 PM

Remove the intake and valley pan and see what you're dealing with. There's no way to replace a lifter without taking it apart at least this far anyway.

I wouldn't replace a single lifter that had excessive wear on the face. Putting in a new cam and lifters is the only way to fix it if this is the case, as the one lobe that ran the bad lifter will be worn too.

Maybe the valve adjustment was a little too loose to begin with, a readjustment might be in order. Remove all the pushrods before you do this and roll them on something flat (glass) to check for bent ones.

Sorry to see you're having trouble, just take it down far enough to properly assess the situation and go from there.

cdoggy81 · 08-26-2007, 03:15 PM

It was still running fine though? Just the tick?
I agree with B-Man as well. I would say pull the pull the intake & valley pan & take a look see. Sweat equity = cheap insurance...

(Napa stuff has always seemed to be higher quality IMO)

getmygoat · 08-26-2007, 03:42 PM

It was more of a clack than a tick.

I think it was running pretty good before I shut it down... I thought maybe I could hear a coorespondance between the clack and the exhaust, but there was no popping or sputtering or anything severe....

68bird400HO · 08-26-2007, 11:17 PM

Are you running with the original bottleneck rocker studs with the nuts cranked down to 20lbs? I don't think you can do that with most aftermarket cams. I believe you need to run an adjustable valvetrain with the BBC studs.

getmygoat · 08-27-2007, 11:03 AM

Yes, its a stock valve train except for the cam.

I noticed the rocker nuts are installed with the beveled side up.. Is this correct?

george kujanski · 08-27-2007, 11:53 AM

I would do this: If you can snug the rocker down with no play in the pushrod, turn the engine over and see if the valves on that cylinder have the normal amoount of valve lift. If not, a cam lobe is suspect.

If the lift is good, you just may need an adjustable valvetrain, but taking off the intake and checking the lifter and lobe will certainly tell the tale.

George

Jim Scites · 08-27-2007, 12:18 PM

You might check to make sure the rocker stud didn't loosen up.

68bird400HO · 08-27-2007, 01:11 PM

Quote:

Originally Posted by getmygoat

Yes, its a stock valve train except for the cam.

I noticed the rocker nuts are installed with the beveled side up.. Is this correct?

The problem, as I understand it, is that to achieve the lift the newer cams do, the baseline circle of the cam is smaller. Keep in mind that the factory cams, like the 068, only had 0.407 lift with the 1.50s and that is what the original valvetrain is set up for (cranking the nuts to 20lbs). With any newer cam you need to be able to set the lash for each valve. There is a specific procedure to follow to make sure you are setting each one with the lifter on the baseline and not on any part of the lobe so it is all the way down.

getmygoat · 08-27-2007, 01:24 PM

Well, working from home has its advantages.

I pulled the intake and here are the pics.

THe big question is this lifter, its been a while since I've been around them. Should the "plunger part" move up and down when you shake it? i.e. its "loose" in there. (See the first pic). When I turn it upside down, that plunger part falls against the retaining ring... is that normal?

The cam lobes seem to have some wear marks on them.. not sure if this is normal or not, figured you guys would know.

Thanks.

george kujanski · 08-27-2007, 01:38 PM

There is a spring inside the lifter that keeps the plunger extended. Seems like the spring may have fractured. Remove the circlip and pull the plunger out to see.

George

Bill Hanlon · 08-27-2007, 01:40 PM

Two things:

When cutting open a filter don't use a hacksaw. Impossible to tell if metal if from the hacksaw or your engine. Use something that slices like tin snips. There is actually a special tool to do this job.

I don't think there should be any "slop" in a hydraulic lifter. There is an internal spring that should prevent slop. Not saying that the lifter is the only problem, but it is at least one problem.

steve · 08-27-2007, 01:53 PM

yeah, it dont look like my lifters....the inside part of my lifters (you know the watchamacallit) is flush with the clip.....

getmygoat · 08-27-2007, 01:58 PM

OK,

I pulled the clip out. Then the plunger came out and a little washer but nothing else.

I banged the lifter against the floor and brought an inner sleeve to be flush with the top of the lifter case (hope that is clear).

Got a pair of vice grips on it and started pulling it out of the "shell" - It actually fought back, like there was a spring holding it inside the lifter... then all of the sudden it gave up, and came free. Now when I push it back down in there the spring works like it should, and forces the inner sleeve back out of the "shell"

Its as if it was "stuck"

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