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Valvetrain clatter/noise

The more I get into this I can't help but
think that these bent pushrods were installed
at the time of the rebuild. A mix-up?
Who knows. All but two show to be
original to the engine.
The cam lobes look normal as do the lifters.
All lifter ends are slightly convex and show
no abnormal wear. None are collapsed.
There is also no evidence of coil bind.
Good spacing of the coils at full compression.
I'm inclined to just purchase new stock
length pushrods (9.315). Does anyone
here suggest a new set of lifters as well?
A few of the valves show evidence of squaring
up as there some minor grind marks on top
of the stems. All stems are flat using a
straight edge. Rocker arm wear is minimal
and looks normal for the few hours this engine's
been run. Good oiling up top as evidenced
by the pics.
Thanks all for your input.
 
Last edited:
Check the amount of lifter preload with the current pushrods...... buy new pushrods in a length that will improve that situation if deemed necessary.

One of the old hollow pushrods can be sacrificed to make it an adjustable checking tool.
 
PRHeads said:
Check the amount of lifter preload with the current pushrods...... buy new pushrods in a length that will improve that situation if deemed necessary.

One of the old hollow pushrods can be sacrificed to make it an adjustable checking tool.
Click to expand...
Thanks. Any info on how to do this?
There is still something I'm not catching on
to here. There are no wiped lobes, lifter/cam
wear appears normal after break in, no lifters
are soft/have concave faces, top end is oiling
well, no adverse events during break in, vacuum
holds steady @15, compression a 150 thru
5 cycles on all 8, engine runs smooth with no
pops, misfires, or misses, and no coil bind.
Exhaust manifold gaskets hae no leaks.
But I've got 12 bent pushrods?
The builder assembled this engine from
a hodge podge assembly of parts. 1968
block, 452 heads, machined balancer,
forged crank from who knows where.
My bet is he used some pushrods from
a stock 440, and didn't check their
integrity. They were installed being bent.
 
Last edited:
Could there be no piston/valve interference that caused this, not saying a full hit but they could be just kissing each other causing a small bind up in the valve train.
Cam is set as it should or (over)advanced?

1STMP said:
My bet is he used some pushrods from
a stock 440, and didn't check their
integrity. They were installed being bent.
Click to expand...
Hopefully you are right and that is all it was.
 
After you’ve made your adjustable pushrod, use it as a gauge to check the length required to fill the space between the lifter while on the base circle to the closed rocker arm.
Just extend it far enough to take up the space, and don’t preload the lifter at all.
Remove the rocker, pull the checking pushrod and measure the length.
However much longer the pushrods in the motor are than the checking pushrod is the amount of preload.

7AE52559-2503-4281-A116-732348163CB0.jpeg
 
Just a thought. How much lift will a stock 452 head take? Not the springs but the retainer to valve guide boss. That gets over looked a lot and will bend pushrods easily without hurting cranking pressures. I am putting a .505 lift cam on my stock 452's and you have me wondering now.
 
Gunner1 said:
Just a thought. How much lift will a stock 452 head take? Not the springs but the retainer to valve guide boss. That gets over looked a lot and will bend pushrods easily without hurting cranking pressures. I am putting a .505 lift cam on my stock 452's and you have me wondering now.
Click to expand...
I've read that .515 is about as high as you want
to go. (with 1.5 ratio rockers).
The cam I'm running has a .480 lift.
 
Wietse said:
Could there be no piston/valve interference that caused this, not saying a full hit but they could be just kissing each other causing a small bind up in the valve train.
Cam is set as it should or (over)advanced?


Hopefully you are right and that is all it was.
Click to expand...
Checked this with a bore scope. All pistons
tops nice and flat. No dings.
 
1STMP said:
An update:
Pulled the valve covers off and found 16
of the pushrods slightly bent. Haven't
checked the lifters yet as I'm hesitant
about pulling the intake. Going to try and
pull them with a magnet. Four or five rockers
we're loose enough that the pushrods
may have come out of the lifter. Sighting
down the holes in the heads looking at the
lifters, they all seem to be at the same level
in the cups. (none collapsed) Wasn't able
to push any of them down.
Will report on the cam condition when I get
the lifters pulled.
There is oil at the top end.
Thanks all !
An edit: Measured with a tape measure @
9.25 so I am thinking they're a stock 9.315
pushrod.
Click to expand...
You said in post #36 that four or five rockers were loose enough that the pushrods may have come out of the lifter.
 
Orig69 said:
You said in post #36 that four or five rockers were loose enough that the pushrods may have come out of the lifter.
Click to expand...
They didn't, but were the most bent.
Cylinder 1. Checked for sticking valves also.
None hang up, and valve stems are straight.
Going to make a pushrod tool as PRHeads
recommend.
There are three different pushrods listed
for stock 440's. 9.315, 9.295, 9.030.
The ones installed are the 9.315's.
Cylinders 5 and 6 had the straight push rods.
Tried to depress the lifter plungers and all
are solid. Are new pushrods going to bend
while bolting the rocker shafts back on?
 
Last edited:
Orig69 said:
Was the engine making noise the very first time you started it?
Click to expand...
Not that you could hear over the header
noise. No backfires or misses during run in.
Temps didn't get above 210. 2000 rpm
+ 500 varied for 20 minutes.
We've since changed the oil and other than
some light Grey fine material in the filter,
nothing looks like it's been chewed up.
 
Are new pushrods going to bend
while bolting the rocker shafts back on?
Click to expand...

The valves will just open a bit until the spring load collapses the lifter.
After that point, with the lifter on the base circle of the cam....... the pushrod will spin pretty freely.

How about a pic of the most bent pushrod?
 
1STMP said:
Checked this with a bore scope. All pistons
tops nice and flat. No dings.
Click to expand...

Once you got new push rods I would double check your PV clearance with checking springs.
If there is an issue you might repeat the same damage.
 
PRHeads said:
The valves will just open a bit until the spring load collapses the lifter.
After that point, with the lifter on the base circle of the cam....... the pushrod will spin pretty freely.

How about a pic of the most bent pushrod?
Click to expand...
Can't tell from the pic, but it's bent about 1/8".
There are also spiral serrations running the
full length. There also appears to be three
different styles of rods from looking at the
wear patterns.
20220402_170656.jpg
20220402_170732.jpg
20220402_170701.jpg
 
I meant the full length of it, maybe next to a straight one.

That’s a factory pushrod.
They’re actually “rods”, as in solid, instead of tubing which is what the aftermarket will usually be.
 
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