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noisy valve train

Started by chargerdon, March 30, 2018, 11:57:33 AM

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chargerdon

I have a 76 360 LA engine that was built by a professional engine builder about 1000 miles ago with what sounds like a noisy valvetrain.   The noise sounds like it comes from the passenger side of the engine.    Engine has a Mopar Performance 508 flat tappet hydraulic cam (292 duration) with about a 9.5 compression...   It is not a knock but a low volume valve tick, plus just a general "clatter" that definitely gets louder with revs..but again, no solid valve tick.   

I've pulled the valve cover on that side when engine was cold and checked standard mopar looking valvetrain.   On each cylinder when valves are closed, there is no noticeable clearance...i.e pushrod seems tight against the rocker arm...  and i cant feel any clearance, yet,  I can "spin" the pushrod with my fingers, but cannot feel any clearance...   

One thing i noticed, and do not know if "normal" is that on each cylinder, when valves are closed, i can slide the rocker back and forth on the rocker shaft...maybe .25 to .35 an inch. ...   Is that normal?????   

Besides disasembly to check the hydraulic lifters, what else can i do to find out what the problem is?    Manual says to start the engine when cold and feel each rocker as they operate, but, dont really want to do that as it will create a mess...   Oil pressure when idling at 1,000 rpm when cold is over 60 PSI...   when fully warmed up and at 1,000 rpm idle oil pressure is around 40 psi (with mechanical gauge)

Burdar

QuoteI've pulled the valve cover on that side when engine was cold and checked standard mopar looking valvetrain.   On each cylinder when valves are closed, there is no noticeable clearance...i.e pushrod seems tight against the rocker arm...  and i cant feel any clearance, yet,  I can "spin" the pushrod with my fingers, but cannot feel any clearance..

With a hydraulic cam, the internal plunger in the lifter takes up the gap.  Even with the valves closed, there should be quite a bit of pressure on the pushrods.  You shouldn't be able to spin them.(unless the lifters are bleeding off oil pressure)  I wonder if your pushrods are the correct length.

QuoteOne thing i noticed, and do not know if "normal" is that on each cylinder, when valves are closed, i can slide the rocker back and forth on the rocker shaft...maybe .25 to .35 an inch. ...   Is that normal?????   

Yes, the rocker arms will move side to side a small amount.  There should be retainers under each shaft bolt that keep the rockers from moving too much.

Cuda Cody

quarter inch of movement seems like a TON to me.  That might be part of the issue.  I'm not a flat tappet expert but I think they need a small amount of preload too, right?   :notsure:


Brads70

Is the noisy side getting oil?

Shane Kelley

Does it sound like just one or two lifters?  What brand lifters?

This is the reason I always run adjustable rockers. So many things effect the valve adjustment with fixed position rocker arms. Deck height, valve stem height and push rod length. 

I have had some issues with Comp lifters. Last set had a couple that wouldn't stop pecking. Changed them out with some Crower cam savers and fixed the problem.

RUNCHARGER

Please tell me the oil is clean.
Sheldon

Chryco Psycho

Lifters can be a problem , they used to make 1000s / day now they is almost no one making them as everything is Hyd roller in production engines if they use lifters at all . Johnson is the only company making good lifters now .
Pushrods should spin , that is normal .
You can pull all of the lifters using a magnet & long screwdriver without removing the intake just reaching between the intake ports if needed .
side movement is .025 right ?

SO here is the next thought , did you use an exhaust gasket if so I bet it has failed , manifolds should be bolted on with no gasket but a thin layer of Ultra Copper silicone only , if you have headers you need a good gasket , Make sure you do not have an exhaust leak as that will cause a tick that will increase with RPM 


6bblgt

from 1969  :takealook:

Chryco Psycho

Cool ad , at least the best in the business survived

HP_Cuda


Prob wrong push rod length...
1970 Cuda Yellow 440 4 speed (Sold)
1970 Cuda clone 440 4 speed FJ5
1975 Dodge Power Wagon W200

chargerdon

I have no idea what brand the hydraulic lifters are.    The engine was built by a professional engine building shop, and installed in a 71
Dart and the cam break-in performed.   Engine was never driven on the street and then removed and sold to the guy i bought the car from.   It hadn't been installed in my challenger yet.   Do i know if the pushrods are the right length?   NO..again built buy a professional shop and i hope they did their job right.   

So, what i'm looking for is how to check to see what is wrong, without just tearing it down and replacing parts.   The noise does have a little bit of "tick" that speeds up with RPM, but, its more of just a "noisy clatter".

1) I will check with a digital slide ruler to see exactly how much side-to-side motion there actually is.   Sounds like being able to "turn" the pushrods with valves closed is ok.   

2) Regarding oil...yes...it is very clean oil.   I'm running Napa 10-30w synthetic to which i have added a pint of Lucas oil stabilizer, and a pint of Rislone Zinc additive.   Again, oil pressure is excellent..   at 1000 rpm idle when cold i have 60-80 psi, and when fully warmed up and 800-900 idle in drive, pressure is 30-40 psi.   

3) Ill check the headers for any leak, but, i think its sealed fine..   

What else can i check without tearing off the rockers and pulling the lifters??????   


Chryco Psycho

 Try to push down on the pushrod side of the rockers after it has been running & the oil pressure is built up , but it doesn't have to be hot & see if the lifter is holding pressure or collapsing , hey should be holding pressure .