Roller rocker arm lash?
Thread Starter
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Roller rocker arm lash?
I have adjusted the lash using Lars' tried and true method (see the tech tips if you don't know what I'm talking about), and yet I still can't seem to get my valves to stop making a huge racket. I know that roller rocker arms make a different noise than stamped ones, but it sounds to me like I've got pushrods and rocker arms clanging together a bit too hard for my liking.
Any thoughts on what might be causing this? This only came about when I decided that I would change valve covers, and when I did, I decided to readjust the valve lash. What a dumb idea. I went from almost no noise, to too much, and now I can't seem to get the adjustment right.
What is the correct lash for roller rockers? I tried 1/2 turn past zero, which worked before, but now doesn't seem to do the trick.
Thanks,
Bob B.
Any thoughts on what might be causing this? This only came about when I decided that I would change valve covers, and when I did, I decided to readjust the valve lash. What a dumb idea. I went from almost no noise, to too much, and now I can't seem to get the adjustment right.
What is the correct lash for roller rockers? I tried 1/2 turn past zero, which worked before, but now doesn't seem to do the trick.
Thanks,
Bob B.
Thread Starter
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Motorhead- I actually went from thin Edelbrock chrome covers back to stock, which seem a lot thicker. At first I thought maybe my 1.6/1 rockers were hitting the covers, but they're not.
At least a solid roller sounds like it's supposed to! Mine sounds like sixteen hammers under there!!!
At least a solid roller sounds like it's supposed to! Mine sounds like sixteen hammers under there!!!
Race Director
Joined: Apr 2000
Posts: 17,672
Likes: 199
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Some covers are much louder than others
OK it's a hydraulic cam ? Cut a long slot in one of the old covers, put it on and start the motor. Do one at a time and loosen untill you here it tick then tight a 1/2 a turn to 1 turn, when your finished there should be no noise except a slight chatter from the rollers
OK it's a hydraulic cam ? Cut a long slot in one of the old covers, put it on and start the motor. Do one at a time and loosen untill you here it tick then tight a 1/2 a turn to 1 turn, when your finished there should be no noise except a slight chatter from the rollers
Last edited by MotorHead; Dec 17, 2004 at 08:41 PM.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Worn lock nuts?
I'm thinking worn lock nuts since u have new heads with guide plates to loscate the p-rods. And hydralic lftrs are the quietest vlv train there is. 
Lock nuts are really only made for 1 adjustment and then should be replaced.
Ok i like to adj lifters/vlvs while mtr at idle. With lock nut lose i tighten nut until p-rod cannot move up or down (no play) but can still turn p-rod with my fingers (yes the engine is running). Now tighten 1/4 to 3/4 turn more (1/2 turn fine). Thats it, now move to next valve. This does make a mess with the vlv oil splash. But i cut up an old vlv cover for just this.
U can also use a thin back-up (locking) nut to lock the lock-nuts in place - this is usually cheapest method and take 2 wrenches. Or buy fancier double lock nuts with an allen head locking screw/nut in the center.
Good luck. cardo0
Lock nuts are really only made for 1 adjustment and then should be replaced.Ok i like to adj lifters/vlvs while mtr at idle. With lock nut lose i tighten nut until p-rod cannot move up or down (no play) but can still turn p-rod with my fingers (yes the engine is running). Now tighten 1/4 to 3/4 turn more (1/2 turn fine). Thats it, now move to next valve. This does make a mess with the vlv oil splash. But i cut up an old vlv cover for just this.
U can also use a thin back-up (locking) nut to lock the lock-nuts in place - this is usually cheapest method and take 2 wrenches. Or buy fancier double lock nuts with an allen head locking screw/nut in the center.
Good luck. cardo0
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Robert:
What rocker arms are you using? Are they aluminum body full roller or a semi-roller like the Comp Magnum? If you are using your stock L-82 cast aluminum covers the covers have oil drippers cast into them. When using your stock covers with a full body aluminum rocker is is most likely that the rockers are touching the covers. It does not take much contact to make a LOT of noise. Roller rockers may be slightly noisier on a solid lifter cam but should be just as quite as a stock rocker on a hyd. cam.
I would take take another real close look at the covers for contact or temperarilly put the chome covers back on to see if the noise goes away.
What rocker arms are you using? Are they aluminum body full roller or a semi-roller like the Comp Magnum? If you are using your stock L-82 cast aluminum covers the covers have oil drippers cast into them. When using your stock covers with a full body aluminum rocker is is most likely that the rockers are touching the covers. It does not take much contact to make a LOT of noise. Roller rockers may be slightly noisier on a solid lifter cam but should be just as quite as a stock rocker on a hyd. cam.
I would take take another real close look at the covers for contact or temperarilly put the chome covers back on to see if the noise goes away.
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by thebruce
Motorhead- I actually went from thin Edelbrock chrome covers back to stock, which seem a lot thicker. At first I thought maybe my 1.6/1 rockers were hitting the covers, but they're not.
At least a solid roller sounds like it's supposed to! Mine sounds like sixteen hammers under there!!!
At least a solid roller sounds like it's supposed to! Mine sounds like sixteen hammers under there!!!
Thread Starter
Racer
Joined: May 2001
Posts: 401
Likes: 0
From: Carlsbad CA
Problem solved
Turns out Pete was on the right track. Despite no evidence of contact (and I looked again very closely) the rockers must have been contacting the oil drippers. Noise went away with the chrome covers back on, so I ground down the oil drippers about 1/8" and the stock covers are nice and quiet. Thanks to all.
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