Hey guys. New to the forum. Looking for advise. I just put a very light cam in my 340 Cuda. Replaced cam, lifters, push rods & new rocker assemblies. Car runs great & sounds great until operating temp is reached. Lifters, rockers get very noisy. Car runs great but sounds like crap. Any help will be greatly appreciated. Thx.
First, welcome aboard. :welcome: Roller or flat tappet ? Hyd or solid ? Give us some more info on the motor. :wave:
30-45 at idle. Sounds like crap at stop light but runs great. ????
Pretty much a stock 340 except for very light cam. I removed a heavier cam & wasn't making this noise. I'm gonna check the old pushrods & see if they are longer than the new ones.
If your Oil pressure is lower than 45 Lbs at idle, that could be the cause, Oil Pressure should be between 45 & 65 Lbs at 1000 R.P.M.
Does the noise go away when you rev it to 1500 rpm and your oil pressure climbs?
I attached the Service Manual instructions for 340's about Tappet Noise. See attached PDF's
Could be a spring issue or possibly PTV issue.
Well with a " big cam" you get valve springs to match. Could be your problem with the new smaller lift the springs are wrong. Check your cam card for the specs and then try and get them for Your old cam Or a problem with your push rod length as you said.
Tough to diagnose from here !
First welcome to the site .
Pushrod length is my first thought , the cup in the lifter could be slightly lower so the lifter cannot adjust , do you know what brand of lifter was used , the Only good one left is Johnson , another though is are the rocker shafts on properly with the oil holes pointed down ?
Pushrod length was my first thought too. Have you double checked to see if they are adjusted right?
What oil are you using?
If new 'stock' rocker shafts installed, are they installed with rocker oiling holes in correct position? A previous owner of my spare 340 had installed the shafts UPSIDE DOWN... you wouldn't have much oil pressure that way though... but the holes for oil need to point toward centerline of engine (and I believe the slots on end of shafts go to the front, as I recall).
It's like your lifters aren't pumping up... did you soak them prior to install?
Echo: My first inclination is the rocker shafts are installed wrong, second is pushrod length.
the engine will keep oil pressure with the shafts upside down as it only oils the shaf for a split second as the cam goes around , it is not a constant feed :alan2cents:
Hey guys: Thx for the replies & help. I did find that the new pushrods length is shorter by ten thousandths. Gonna try old pushrods & go from there. Thx again.
.010 should not make a difference if it is in range with the lifter , let us know how it turns out
was new cam put in with old valve springs?
what weight oil you using?
Valvoline VR1 30 weight. I put my old push rods back in which are .010 longer hoping for the best, but valve train still noisy. Read several articles of other people having the same issue. This is the first small block mopar I've had. Always had big blocks. Never had this problem b4. It has been suggested to just ignore it & drive it...There has got to be a fix. Probably next move is going back with an all stock valve train...This is crazy.
I've had great luck with stock value trains. :alan2cents:
the lifters could be the wrong application , with the oil groove at the wrong height
Have you pulled the valve covers or cover off to see what's going on? 30 wt might be a little light or maybe add some STP or something with ZDDP. With the covers off you can apply some pressure to the rockers. I ran roller rockers on one of my hemi's and the rockers were slightly hitting the baffles on the stock covers.
Welcome!
:welcome:
What brand lifters? Adjustable rockers or stock stamped? I ran Comp lifters and never could get them quiet. Switched over to the Crower cam saver lifters and solved the issue. Heavier oil will help general valve train noise but not pecking lifters.
Crowed cam & lifters. I did add baffles to the valve covers but I see no sign of rocker arm contact. I'll recheck. I'm rewiring dash at this time but I'll get back to valve train noise next. Thx.
Quote from: jabber353 on January 17, 2018, 03:18:59 PM
Pretty much a stock 340 except for very light cam. I removed a heavier cam & wasn't making this noise. I'm gonna check the old pushrods & see if they are longer than the new ones.
Not trying to hijack the thread, just looking to learn. What's a "heavy" vs. a "light" cam? I haven't seen these terms before. I've mostly heard terms around lift, duration and overlap regarding cams.
Push down on the pushrod side of the rocker & see if the lifter collapse ,, they should be hard & not give at all .
Johnson is the only good mfg left for flat tappet lifters
Quote from: Dakota on January 30, 2018, 05:19:23 PM
Quote from: jabber353 on January 17, 2018, 03:18:59 PM
Pretty much a stock 340 except for very light cam. I removed a heavier cam & wasn't making this noise. I'm gonna check the old pushrods & see if they are longer than the new ones.
Not trying to hijack the thread, just looking to learn. What's a "heavy" vs. a "light" cam? I haven't seen these terms before. I've mostly heard terms around lift, duration and overlap regarding cams.
I believe he is referring to a mild vs. wild.