Valve train noise
Thread Starter
Intermediate
Joined: Feb 2011
Posts: 47
Likes: 0
From: Clinton Ia
Valve train noise
I'm trying to get some feedback on what you guys consider "noisy" valve train on a cammed car. My car has afr heads and a comp cam w/ 918 springs (about 15k miles) I can hear the clattering inside the car faintly at cruising speeds and noticeable at 2500-3000. Outside the car with the hood closed it definatlely sounds like a sewing machine. Normal? or start pulling valve covers? I've put about 1500 miles on the car since i bought it and it doesn't seem to be getting louder, just in the back of my mind since my dad just dropped a valve in his 02'.
Tech Contributor
Joined: Sep 2005
Posts: 1,731
Likes: 82
From: New Market AL
You can't expect much feedback without giving the specs on the cam duration and lift. But as a general answer - yes, most aggressive ramp rate cams will have audible valvetrain noise. You should probably start collecting some replacement springs to get rid of those 918s. Single springs just don't give you much protection if/when one of them lets go.
Melting Slicks
Joined: Aug 2004
Posts: 2,237
Likes: 9
From: Springhill FL
Your car sounds like a typical LSx car with a cam. Its simply part of the deal when you change the valvetrain on these engines. 
Oh noes! Nearly every ohv V8 car ever made is on the verge of spontaneous implosion!
I've run 918s in both my vettes. One with cam and boost and the other with a cam over .600" lift. Daily driven and tracked regularly. Still waiting for a shark to jump out of my engine bay to bite me while I get struck by lightning.
Oh noes! Nearly every ohv V8 car ever made is on the verge of spontaneous implosion!
I've run 918s in both my vettes. One with cam and boost and the other with a cam over .600" lift. Daily driven and tracked regularly. Still waiting for a shark to jump out of my engine bay to bite me while I get struck by lightning.
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
My concern is the 918's with the AFR heads, the valves in the heads are on the heavy side. Have you put the car on a dyno to ensure you still have valve control in the upper RPM range?
Tech Contributor
Joined: Sep 2005
Posts: 1,731
Likes: 82
From: New Market AL
Mawnee, I understand your confidence in using single beehive springs. They work just fine on LS1s from the factory and even with smallish aftermarket cams. I ran a set of 918s with a 226° duration cam for 22k miles without any problem.
But, my friend recently had a spring break, dropping the valve into the cylinder, and killing his LS6 block and one 243 head. With that failure fresh on my mind, I would recommend folks spend a few more dollars on double springs. But to each his own.
But, my friend recently had a spring break, dropping the valve into the cylinder, and killing his LS6 block and one 243 head. With that failure fresh on my mind, I would recommend folks spend a few more dollars on double springs. But to each his own.
Team Owner
Joined: Jan 2007
Posts: 29,059
Likes: 1,837
From: cookeville tennessee
Mawnee, I understand your confidence in using single beehive springs. They work just fine on LS1s from the factory and even with smallish aftermarket cams. I ran a set of 918s with a 226° duration cam for 22k miles without any problem.
But, my friend recently had a spring break, dropping the valve into the cylinder, and killing his LS6 block and one 243 head. With that failure fresh on my mind, I would recommend folks spend a few more dollars on double springs. But to each his own.
But, my friend recently had a spring break, dropping the valve into the cylinder, and killing his LS6 block and one 243 head. With that failure fresh on my mind, I would recommend folks spend a few more dollars on double springs. But to each his own.
That old saying about a ounce and a pound thing.
