Rocker Arms really Loose
Thread Starter
Intermediate
Joined: Mar 2021
Posts: 49
Likes: 0
From: Florida
Rocker Arms really Loose
So I heard a ticking noise coming from me engine and decided to check it out, and I'm glad it did. The rocker arms have tons of side to side play, but they still only have about 0.024 clearance like their supposed to. Would this be due to worn out rocker arms or are they just not tight enough?
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,555
Likes: 7,006
From: New Or-leens Loo-z-anna
Rookie reply: the lifters are "bleeding down" after the engine is stopped and it cools off.
There are some good threads recently about adjsting them correctly without bending a pushrod or burning a valve.
Do a forum search......"adjusting lifters" or "adjusting rocker arms".
There are some good threads recently about adjsting them correctly without bending a pushrod or burning a valve.
Do a forum search......"adjusting lifters" or "adjusting rocker arms".
Team Owner
Joined: May 2001
Posts: 87,298
Likes: 1,579
From: Western NY
So I heard a ticking noise coming from me engine and decided to check it out, and I'm glad it did. The rocker arms have tons of side to side play, but they still only have about 0.024 clearance like their supposed to. Would this be due to worn out rocker arms or are they just not tight enough?
The Rocker arms in question
The Rocker arms in question
First question...is it a solid lifter cam or a hydraulic lifter cam?
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
What type of oil are you using?
Generally speaking, rocker-arm tips don't wear out. Cam lobes do.
I don't have a solid cam, but 0.024 seems a little generous to me. Where did you read the specs on valvelash if you don't mind me asking?
Generally speaking, rocker-arm tips don't wear out. Cam lobes do.
I don't have a solid cam, but 0.024 seems a little generous to me. Where did you read the specs on valvelash if you don't mind me asking?
Dr. Detroit
Joined: Mar 2012
Posts: 10,093
Likes: 4,017
From: New Braunfels Texas
Well...this isn't an LT-1, so verify that it is a solid lifter camshaft.....all LT-1's came with guide plates and the LT-1 was the only solid lifter small block available. Older 327's had solids with no guide plates from the C2 era.
Jebby
Jebby
Team Owner
Joined: May 2001
Posts: 87,298
Likes: 1,579
From: Western NY
But when dealing with older cars, the current owner may not know the history of the car, with respect to what may have been (either correctly or incorrectly) done to it.
Tech Contributor
Joined: Aug 1999
Posts: 14,365
Likes: 6,345
From: At my Bar drinking and wrenching in Lafayette Colorado
If it has hydraulic lifters, the valves that are closed will have lifters that are bled down after shutdown, so it's normal for the rockers to feel very "loose", and they can be wobbled from side-to-side with the lifters bled down. There will be "lash" in the amount of the lifter pre-load, which will be in the .025"-range. Completely normal. If they're "ticking," adjust them. E-mail me for my paper on how to do it (and no - you don't adjust them with the engine running). Before adjusting, verify that you don't have a cam lobe that has gone flat by disabling the ignition system and cranking the engine over while observing the rocker movement - the loose rockers should visually have the same "travel movement" as the others.
If you have solid lifters (unlikely in the engine shown in your photos with no guideplates) you should check and adjust the lash to the cam manufacturer's specs. Lash specs vary by cam grind and manufacturer anywhere from tight-lash cams with .015" lash to the factory solid cams running about .026".
Lars
V8FastCars@msn.com
If you have solid lifters (unlikely in the engine shown in your photos with no guideplates) you should check and adjust the lash to the cam manufacturer's specs. Lash specs vary by cam grind and manufacturer anywhere from tight-lash cams with .015" lash to the factory solid cams running about .026".
Lars
V8FastCars@msn.com
Last edited by lars; May 25, 2021 at 04:46 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
Is that the original cam, and is it solid or hydraulic? Did you do any engine work prior to this noise? I'm assuming it was running fine at one time. Is this a driver, or has it sat for a while.
If you did adjust the lash, how long ago was it done?
If you did adjust the lash, how long ago was it done?
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
If these are hydraulics that have bled down then why the ticking while running? They should have pumped up. Are they pressed in studs? Is it every rocker, or most. Just wondering if some studs lifted a bit.
Last edited by Mrvettenick; May 25, 2021 at 08:09 PM.
Tech Contributor
Joined: Aug 1999
Posts: 14,365
Likes: 6,345
From: At my Bar drinking and wrenching in Lafayette Colorado
Geezus... just adjust the lifters, button it up, and drive it. It takes 10 minutes to correctly set all the lifter preloads, which is less time than it takes to read this thread.
Lars
Lars
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
Legit question. And this goes back to post 4: What oil (zinc?) is being used regardless of the type of lifter, solid or hyd.
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
If it's a wiped cam. I would adjust one rocker to zero lash, then rotate the cam to see what lift is there, and does it match the cam spec. I would not run that engine until you are sure what you're up against.