Proper Valve spring Height?
Drifting
Joined: Nov 2002
Posts: 1,365
Likes: 3
From: Huntsville AL
Take a look at your pushrods. With the 1.6 ratio rockers, the pushrod may be hitting the cylinder head at the pushrod hole because it is now closer to the rocker stud. Check for wear marks on the pushrod and around the pushrod hole.
Thread Starter
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
I inspected the pushrods pretty good during the cam swap and they all seemed to look great. Lifters looked good too.
Although as of my order today, I am replacing both.
I've used the stethiscope on them too but the tic only starts happening at 2K rpm and up. Its not present at idle. They all sound the same at idle. I can't run the motor with the valve covers off at any speed above idle due to the oil pump starts really throwing it out!!
Although as of my order today, I am replacing both.
I've used the stethiscope on them too but the tic only starts happening at 2K rpm and up. Its not present at idle. They all sound the same at idle. I can't run the motor with the valve covers off at any speed above idle due to the oil pump starts really throwing it out!!
Last edited by VR'92; Jul 1, 2005 at 11:30 AM.
Drifting
Joined: Nov 2002
Posts: 1,365
Likes: 3
From: Huntsville AL
Todd said if it was just a loose rocker, you should be able to hear it at idle. Sounds like something else is going on. Did you roll the pushrods on a piece of glass or something to see if they were all straight? Kind of a moot point now that you have new pushrods coming in.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Though installed height does not effect pre-load it does indeed effect valve control by setting seat & over to nose spring forces.
The spring mfg should provide the load at some installed height as well as the spring constant.
My stock springs only provided ~86lbs on the seat and I shimmed my Comp Cams springs to ~110lbs to assure valve control with my ProMagnums.
Since your problem starts at elevated RPM it may well be a matter of spring load.
The spring mfg should provide the load at some installed height as well as the spring constant.
My stock springs only provided ~86lbs on the seat and I shimmed my Comp Cams springs to ~110lbs to assure valve control with my ProMagnums.
Since your problem starts at elevated RPM it may well be a matter of spring load.
Advanced
Joined: Jun 2002
Posts: 76
Likes: 0
From: Huntsville AL
louder than my LT4
Victor and I compared ticks the other day. His sewing machine is definitely louder than mine. My LT4 has what I might call a muted, soft tick, whereas Victor's LT4/1 has a very sharp ticking. Would you agree Victor?
Lemme know if you want to borrow my HF stethoscope.
zrated
Lemme know if you want to borrow my HF stethoscope.
zrated
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Generally, the more aggressive the cam/rocker ratio is, the more valvetrain noise. Hope none of your springs are broken; they can run OK and quiet at idle and make the noise you are talking about. Don't want to get you worried but it is a possibility albeit remote.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by 65Z01
My stock springs only provided ~86lbs on the seat and I shimmed my Comp Cams springs to ~110lbs to assure valve control with my ProMagnums.
Since your problem starts at elevated RPM it may well be a matter of spring load.
Since your problem starts at elevated RPM it may well be a matter of spring load.
I really don't think the installed height of the springs is the problem, here. They may be set wrong, but I doubt they are the cause of the noise.
RACE ON!!!
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
Originally Posted by Corvette Kid NC
I think they're the same as an LT1 which is 1.78" factory spec.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Originally Posted by zrated
Victor and I compared ticks the other day. His sewing machine is definitely louder than mine. My LT4 has what I might call a muted, soft tick, whereas Victor's LT4/1 has a very sharp ticking. Would you agree Victor?
Lemme know if you want to borrow my HF stethoscope.
zrated
Lemme know if you want to borrow my HF stethoscope.
zrated
w/ that.and thanks for the good responces, guys. I'll have plenty to do when my new parts come in.
