Valvetrain clatter/noise
- Thread starter 1STMP
- Start date
I suspect something to do with lifter(s) not pumping all the way up at idle - and/or God forbid, a lobe or two on the cam is flattening out.
What oil you running in it?
What oil you running in it?
It's been recently broke in. Straight 30 wt.
break-in oil with zddp. Per the engine builder's
recommendation.
Guess I'll pop off some valve covers and do
some snooping.
Will post what I find.
Good to read about the zinc. Yep, see what's up with the valve cover(s) (start with the one you're
hearing the most noise out of) off.
BLK 68 R/T
Well-Known Member
I would verify oil flow to the top end. Should be pretty easy to tell, followed by rocker shaft orientation.
Thanks for your input.
I'll be pulling the valve covers tomorrow.
Geoff 2
Well-Known Member
Cannot believe we are at 26 posts & nobody has suggested this simple test. Run engine for 3-5 minutes [ no more, not too hot ]. Remove a valve cover. Check for loose rockers. Loose rockers could indicate faulty lifters, cam brg in wrong, wiped lobes, wrong length valves [ too short ], etc.
I listened to the video a couple times.
If..... your oiling fine on top, it sounds like lifters do not have much for preload,
Or roll it over by hand and check springs for coil bind.
Sounds like its running nice.
Orig69
Well-Known Member
It kinda sounds like it's only one or two lifters, hard to tell it's so loud.
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Kinda what I was thinking, as the compression
is even across the board. I would think a
bad cam shaft would show signs of rough
running. It idles smooth with no pops or
missing.
We're pulling the covers off today
to check for bent pushrods and bad lifters.
PurpleBeeper
Well-Known Member
Nope, compression would be fine. The valves won't open up completely, so you'll be low on power, and you will have a knock-knock-knock coming from under the valve cover
Thanks for the info....
Barry Woodyard
426 Woody
I have a complete rebuilt 426 Max Wedge.
Comp Cam with Hydraulic roller lifters. had it assembled by the machine shop that did all of the machine work. When I first started it had a lot of lifter noise. I pulled the Rocker covers and re adjusted them. The Machine shop told me they go 1/4 to 1/2 turn past 000 lash. still a lot of noise. I have the stock Adjustable rockers on the engine. Still a lot of noise. I called Comp Cams and they told me you need .050 to .080 preload. With a 3/8-24 thread on the pushrod end of the rocker that is up to 2 turns (1.000/24) = almost 2 turns. Adjusted them again and it is stilll noisey but better. The rule of thumb of 1/4 to 1/2 turn is for Chevy which is adjusted in the center of the rocker arm not out at the end like the Mopar which make a lot of difference.
Comp Cam with Hydraulic roller lifters. had it assembled by the machine shop that did all of the machine work. When I first started it had a lot of lifter noise. I pulled the Rocker covers and re adjusted them. The Machine shop told me they go 1/4 to 1/2 turn past 000 lash. still a lot of noise. I have the stock Adjustable rockers on the engine. Still a lot of noise. I called Comp Cams and they told me you need .050 to .080 preload. With a 3/8-24 thread on the pushrod end of the rocker that is up to 2 turns (1.000/24) = almost 2 turns. Adjusted them again and it is stilll noisey but better. The rule of thumb of 1/4 to 1/2 turn is for Chevy which is adjusted in the center of the rocker arm not out at the end like the Mopar which make a lot of difference.
Should be playing golf
Well-Known Member
Sure hope you have checked your header/manifold bolts for proper torque. Just my 2 cents...simple things first eh?
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.
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.
Last edited:
Orig69
Well-Known Member
Do you have a picture of the pushrods.
No. They weren't bent that bad to where you
can see the deformations in a pic. There
is two different types of pushrods. 8 are
solid non-ball ends, 8 have ball ends. I don't
have any way of accurately checking their
length. The valve stem ends are flat and even.
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