Technical 396 lifter noise help.

I bought a used but recently overhauled (5000 miles) 69 396 325hp. took off the pan, intake and looked it over and found a couple flat cam lobes, but everything else looked new. Put in a new double roller timing set and a (Summit) hydraulic cam and lifters with slightly more performance spec than a stock 325hp. It runs good but I have at least 2 lifters on the passenger side still clicking and we set them twice running. We did set the valves cold (zero lash plus 1/4 turn) and then started and reset warm running. We repeated this cold and running set after backing off the rockers and letting it sit over night. Do I possibly have broken (inner) valve springs? Oil pressure is great and it's running normal temp. We did put new rockers on, we did roll the push rods and checked both ends for galling or deforming. Would it possibly be a collapsed lifter. A couple rocker arm studs have more threads showing after setting. It is idling smoothe, not shaking, at around 900 and I bumped the timing up to about 14-16 and it has good power and acceleration without a bog/hesitation. We have less than 2 hours running on the new cam and only a couple short test drives-maybe 2 miles, not over 3500 rpm.

 

Maybe give them another 1/2 turn? Or possibly air in the lifters. Lippy

 

I am not going to try and answer your question but I am going to tell you a story:

I screwed the timex 355 together in 1997. I started out with a set of lifters that all stuck and even after lapping them I could not keep them from sticking. I ended up with a set of Erson anti-pump-up lifters that I am still running. I chased a ticking lifter for over a month, adjusting at least once a week (it was my daily driver back then). Finally one day I had the hood up running it trying to decide if I was going to live with then noise or not. I put my hand on the rocker cover and felt a little puff of hot air on my wrist. I reached across and whacked the throttle and the noise died down a little bit but I still felt the puff of hot air on my wrist. I checked the header bolts and one had backed off. I lay the header back and pulled the gasket, it was burnt. Replaced the header gasket and my ticking lifter was cured.

 

Ive only messed with a couple 396s. Both broke stock springs after a performance cam install.

 

Keep it coming, guys. Good input gives me things to check out. Thanks, it's been over 40 years since I worked on old motor issues and I need the help to jog the old memories, not to mention my best big block "go to" guru buddy has passed.

 

I also remember (although his engine is fresh), Some BBC's had a lifter ticking problem. GM said drill a such and such hole size, in the front lifter galley plug to purge the air. I still set them running at 1/2 turn, no problems. Lippy.

 

What year 396 is this? Nevermind,,,,duh. Lippy

 

One thing I would want to check since this block has a past, is to make certain that the offending lifter bores have not grown into egg shape. If a bore is out of round it can slow the travel speed of the lifter.

 

Haha, this reminds me of a story from when I was a young man, still in my 20's, not too long after I had got into the heavy equipment repair business, I was a Mechanic's Helper and was assigned to help a Journeyman mechanic with an engine job out in the field. My job was basically to be a second pair of hands, to fetch tools, clean parts, whatever was needed to help him with the job. It was on a large IH wheel loaded with a straight 6 diesel engine, 817 cu in. We got to the job and he fired it up and it was making an odd noise that sounded kind of like a bearing knock, but not really. He wasn't sure what it was, but we started doing some tests, then ended up digging into the engine, pretty soon the head was off, then the oil pan, then the pistons were out of it, he kept looking for what was making the noise, what was failing, but never really found it. We did find that it was an old engine with a lot of hours on it, and we ended up doing an inframe overhaul. When we got it all back together and fired it up, the noise was still there. Oh crap! He decided to pull the exhaust manifold and disassemble it; we found a leaking gasket, I think it was where the turbo mounted to the manifold. Haha, put a new gasket on it and fired it up, oilla, the noise was gone! Oh man, the mechanic was really embarrassed! I don't know if he ever fessed up to the customer or our boss about it; I never said anything, but I never forgot it either. That was a helluva lesson to learn, but one I never forgot. Exhaust leaks can send you down a long rabbit hole you really don't want to go down!

 

Good point. I did check that when we put the lifters in and everything looked OK. We did have to clean a couple lifter bores to make the lifters move good.

 

Once again another motor mystery.
You mention it came with a couple of flat cam lobes. Any relation to the location of the two lifters still ticking?
You asked about broken valve springs. Maybe? I guess without taking it apart to confirm, you might ask, what kind of noise are you hearing, does it change with engine speed, and does tightening down or loosening the nut change it.
As for the push rods...you should also blow threw them.
Collapsed lifter, or rather one that doesn't pump up...pull the valve cover, undo the rocker, try pushing on it to collapse it or see if it's pumped up.
The studs with a little extra thread showing. Maybe they are pulling out of the head?
Anyhow...I'm sure in time it will get figured out.

 

Amazing that this complete matching 69 (Chevelle code) 396 came out of a boom truck for a sign company. Heads, block and intake all correct dated/numbered--325HP.

 

I did blow through the push rods. I did not push to see if the lifter was collapsed--but I will. Studs are screw in and look OK. The noise went away when adjusting then came right back so I adjusted the whole side again and buttoned it up for timing and test drive. It does seem to just about go away but comes back.

 

I assume you went through the typical cam/lifter break in?

 

I don't adjust valves with the engine running, it's easier to keep track of what's going on when it's not moving.

Could be another wiped lobe, it can happen fast on these engines.

It's pretty common for the interference fit on the nuts and studs to go away, so the nuts back off by themselves. New nuts, and maybe even new studs, can fix this issue. I've had to replace studs to get new nuts to fit tight. Since you replaced rockers, this might not be an issue...but it might...

Did you install new springs that are matched to the cam? If not, you can expect trouble.

 

Well I recall years back my buddy Mike calling about his son's similar trouble. He at the time was a young apprentice mechanic who rebuilt the big block in dad's crew cab truck. I recall it was to do with a oiling issue but can't say for certain. Anyhow, could be something to it? If nothing else a rabbit hole of reading.

396 No oil coming up to rockers | Team Chevelle (chevelles.com)

 

The early 396 blocks (through 66 or 67?) take a different rear cam bearing, and a cam with a groove in the rear journal. By 69 they should all be normal, though.

 

Any chance the ticking could be coming from your mechanical fuel pump? (assuming you are running one).

Years ago I chased a "ticking lifter" with no success, then someone happened to mention the possibility of it being the fuel pump. A new pump fixed the issue. This was a SBC though, I don't know if BBC engines had this same issue.

My other thought is that whatever caused the first cam to fail has now caused the second cam to fail ... when you did the install did you happen to verify (before the intake went on) that all the lifters were rotating on the cam? (meaning "no sticky lifter bores").

The "more thread showing" comment could be a stud or two pulling out as someone mentioned earlier, I have had that happen on a SBC too.

 

Big block studs can't "pull out". They can unscrew, and leave the pushrod guide plate loose, though.

 

yes, on the test stand

 

I suspected the noise could be the fuel pump rod and I did change the fuel pump. We did a cold set with the intake off and could see the lifters move up and down.

 

And of course you changed the oil and filter after break in to flush out the assembly lube from the new cam.

Inspect your new cam lobes!

Anyone know who make the cams and lifters for Summit?

 

Look inside the valve cover on that side and see if there are any signs of rocker contact. I am not familiar with the BBC but I had that problem on a SBC.

 

We did not put new springs in. The cam spec I think was for the stock springs. I will be checking some of these things again tonight. Thanks.

Good read on the Team Chevelle post. I actually did know about the early cam bearings and since I was doing this with my 2 sons, we had the "How to Rebuild Big Block Chevy" book for reference while we tore down and worked on it. I was glad it was all 1969 parts.

 

I read somewhere that the "repro" chrome covers are sometimes too low and the rockers hit.

 

The stock springs are single springs, with a damper. Double springs are usually used when you get to about .550" lift.

 

I've seen a lot of complaints regarding the poor quality of hydraulic flat-tappet lifters.

 

I've also been hearing a lot of cam failures in the past few years. Even from some big names that I have used in the past. God only know where some of this crap is coming from these days.

OP..... When you're in there again make sure your lifters rotate in their bores if you haven't already.

 

This is the surest and safest way to adjust them. Is possible to shove the valve down into the piston while trying to get that noisy (possibly defective) lifter to quiet down. I've seen it done more than once....lesson learned.