Valvetrain clatter/noise

[1STMP]

So when you installed the rockers they were not loose, but they are now after turning the crank. Are the rockers loose a little bit or a lot?

I'm going to put a feeler Guage
between the valve stem and rocker tomorrow
and measure the gap. I don't believe that
once the lifters are fully pumped up that this
play is going away. The rest of the rockers
are tight with no up/down movement. The
lifters in question have not bled down.

 

[Orig69]

Maybe some pictures of the rockers.

 

[Wietse]

Regardless of all valve stem height, you set everything to take the slack out.
Once the lifter is back on the camshaft base the internal spring will have the slack taken up so there should be no slack.
Double check cyl #1 and #6 push rods, they might have bend again??

Use the bore scope to see if these 2 cylinders have a different piston than the others, which may have a different deck height or no valve reliefs and are hitting the valves?

 

[Gunner1]

I would be rechecking the valve tops. If you can recheck the valves with your straight edge again. Maybe a tight guide or a slightly bent stem. It’s a quick check.

 

[1STMP]

Regardless of all valve stem height, you set everything to take the slack out.
Once the lifter is back on the camshaft base the internal spring will have the slack taken up so there should be no slack.
Double check cyl #1 and #6 push rods, they might have bend again??

Use the bore scope to see if these 2 cylinders have a different piston than the others, which may have a different deck height or no valve reliefs and are hitting the valves?

Thanks Wietse,
These are non-adjustable rockers.
We checked valve to piston interferences with
the scope. All 8 are the same. No damage.

 

[Wietse]

These are non-adjustable rockers.

Oops, for some reason I believed you were using adjustable rockers.
Good thing though, my bad scenario is not possible then.
As what Gunner said, tight valve or bend valve stem. If you go check that, I would double check the push rods for straightness regardless.

 

[1STMP]

I would be rechecking the valve tops. If you can recheck the valves with your straight edge again. Maybe a tight guide or a slightly bent stem. It’s a quick check.

Thanks, Gunner.
I'll tap the stem and check for binding. I'm
also going to mic the rockers and make sure
they're round around the shaft.

 

[Orig69]

We know the engine has been sitting for years so turning the crank would cause the valves to open and sticky valves in cylinders 1 and 6 would cause the rockers to become loose.

 

[padam]

Maybe that rocker stand is high.

 

[Gunner1]

I use to have a large pair of Channel Locks. I would grip the rocker arm and lightly depress the valve a few times. Usually the valve would unstick and the pushrod would tighten up. You don’t have to do any removal. Tapping on it like you said works too.

 

[1STMP]

I use to have a large pair of Channel Locks. I would grip the rocker arm and lightly depress the valve a few times. Usually the valve would unstick and the pushrod would tighten up. You don’t have to do any removal. Tapping on it like you said works too.

Thanks, Gunner.
Didn't get a chance to work on anything today.
Wind blowing close to 65mph. Lots of dust &
dirt blowing around.

 

[1STMP]

Supposed to be a very pleasant day tomorrow.
Dial indicator, brass hammer, calipers, bore
scope, straight edge, torque wrench,
stethascope, eyes, ears, and a feeble mind.
With y'alls help, I'm going to get this problem
figured out.
Bought a new set of exhaust manifold gaskets
though I don't believe this is the problem,
but that probability will be eliminated.

 

[Wietse]

Stay strong and persistent... you will win!!
Keep us posted.

 

[1STMP]

The plot thickens. We still have not fired the
motor after replacing the lifters and pushrods.
Broke down and bought a set of 12" calipers
so we could measure the old (slightly bent)
pushrods.
16 measured 9.298 +/-.
2 measured 9.317 (stock length). These
were the 2 new hollow welded ball end. The 16
we're the old solid type.
9.32 - 9.29 = .03 (what we measured for
preload before removing the rocker shafts).
So, with 16 lifters too short on preload and
6 with a strange substance in them, we've
narrowed it down a little further.
None of the valves are sticking, and valve stem
tops are even on both sides. Got good oiling
to the shafts, rocker arms look good with
hardly any wear.
The new lifters do seem to bleed down a
little faster than the old ones did.
Gonna hold my breath, and turn the key.....

 

[1STMP]

Fired up and run 2000rpm/20 min.
With the lifter/pushrod change, 2,4,6,8 Bank
has zero valve train noise. Still have noise
from 1,3,5. 7 is silent.
Going to pull the rocker shaft again and check
for correct pushrod length.

 

[Orig69]

Can you show a picture of the rockers before you remove them from the cylinder head.

 

[1STMP]

Can you show a picture of the rockers before you remove them from the cylinder head.

Yes, tomorrow when the valve covers are off.
Anything in particular you're looking for?

 

[Orig69]

Just to see if everything looks good something has to be causing noise at cylinders 1, 3 and 5

 

[1STMP]

I'm getting really frustrated with this motor.
Don't understand what the builder was thinking
as it looks as though he just threw a bunch
of mismatched and junk parts at it. I'm to a
point now, instead of fixing what I have, to
replace the entire top end with parts that
work.
Parts list: (what's in the motor now)

Cam -TRW TP-238
300/300 adv. 230/230 @.050 480/480 lift
Lobes checked, all good, no damage to
lifter bases.

Lifters - Sealed Power HT-976 (new)
Don't know now if these are junk Bleed down
is fast rate. Pumped up, zero rocker movement
with valves open or closed. After bleed down,
rocker movement on 1,3, and 5.


Springs - Sealed Power VS-675
Free height - 2.300
OD - 1.494
ID - 1.08
Installed open - 1.36 (checked, all good)
Installed closed - 1.86 (checked, all good)
Solid Height - 1.28
Wire Dia - 0.207
# open - 236
# closed - 110

Pushrods:
Were 14 (used) @ 2.980/2 (new)
@ 9.317
Now - 16 @ 9.317 (this change quieted down
2,4,6,8 bank).

Stock (new stamped steel rockers)

No stuck or bent valves.
All valve stems even on both banks
No bent rocker shafts (installed with oilers
pointing down and towards the valves)
with visible good oiling to shafts.
Rocker arms installed correctly
Spark plug wires checked
New header gaskets

After reading many posts here from some
very knowledgeable and helpful FBBO
members, I can't help but think the builder
got by as cheaply as he could.
The bill for this build came to $2700, 27
years ago.
I hope the info provided leads to some
sort of solution, or I'm going to scrap
the cam, lifters, springs, and pushrods
and start over.

 

[Geoff 2]

1st.

Try this on the noisy cyls [ 1, 3, 5 correct? ]. Do on the int & exh lifter. An assistant would be helpful.

Pick a cyl & rotate engine by hand until the valve is closed. Loosen the r/shaft bolts 2 turns & watch to see if the p'rod cup moves up in the lifter. It should. Snug shaft bolts & repeat test until all 6 lifters have been checked.
If the cups do not move, you need longer prods.
If they do move, you could have faulty lifters.
What I have had happen a few times: no matter how long I ran the engine, I had a few clackers. I had to drive the car & give it a WOT burst up to 5000 rpm & that would fix it. Good luck!