Z06 cam and valvetrain noise???
Z06 cam and valvetrain noise??? I have a 97 Corvette with 25000 miles, LS6 intake, Vararam v1B, Dynatech LT headers that are Jet-Hot coated, TCI 3000 torque converter, built and hardened A4 w/ Transgo shiftkit, Z06 catback and 3:15 gearing.
I installed a comp 224 224 .567 .567 115 LSA cam, 7.40 pushrods, and a set of PRC dual valvesprings w/titanium retainers and now I have some valvetrain noise. The noise I'm hearing is what I figure to be "normal" for this setup but with my type A personality it's driving me nuts! It's just noticeable at idle RPM's but when driving "normally" at about 2000 to 2300 38 MPH before converter lockup you can easily hear the valvetrain clatter above anything else. I repeat this is what I figure to be normal noise for this cam but I want to get rid of it or cut it down significantly. I realize that the headers may also contribute to this and am open to make any changes necessary to remedy this. I did a lot of reading on this forum and thought I had picked a cam that wouldn't be noisy (it's has XE lobes) but it seems some people have the noise and some don't. My question to those of you with experience is:
If I change to a Z06 cam and springs will I have any valvetrain noise?
Is the lobe geometry on the Z06 cam such that the valves are opened and closed less aggressively?
I realize that I'm going to give up a lot of power going to the Z06 cam but if it cures the noise it's worth it to me. My only other option at this point seems to be to go back to the stock cam and springs. It would be a shame after all this work to go back to stock and gain nothing more than experience!
Any input is appreciated.
Mark
I installed a comp 224 224 .567 .567 115 LSA cam, 7.40 pushrods, and a set of PRC dual valvesprings w/titanium retainers and now I have some valvetrain noise. The noise I'm hearing is what I figure to be "normal" for this setup but with my type A personality it's driving me nuts! It's just noticeable at idle RPM's but when driving "normally" at about 2000 to 2300 38 MPH before converter lockup you can easily hear the valvetrain clatter above anything else. I repeat this is what I figure to be normal noise for this cam but I want to get rid of it or cut it down significantly. I realize that the headers may also contribute to this and am open to make any changes necessary to remedy this. I did a lot of reading on this forum and thought I had picked a cam that wouldn't be noisy (it's has XE lobes) but it seems some people have the noise and some don't. My question to those of you with experience is:
If I change to a Z06 cam and springs will I have any valvetrain noise?
Is the lobe geometry on the Z06 cam such that the valves are opened and closed less aggressively?
I realize that I'm going to give up a lot of power going to the Z06 cam but if it cures the noise it's worth it to me. My only other option at this point seems to be to go back to the stock cam and springs. It would be a shame after all this work to go back to stock and gain nothing more than experience!
Any input is appreciated.
Mark
TECH Regular
Joined: Mar 2002
Posts: 433
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I've had TR224 and Z06 cams both with 918s.. not much difference between the two. The heads were milled to match smalled base circle of these cams and the noise in both cases very tolerable. You might try 7.425 pushrods to get lifter preload closer to stock. Heavier oil may help keep lifters pumped, 918 springs are likely more quiet too.
On The Tree
Joined: Sep 2004
Posts: 143
Likes: 0
From: St. Clair
As stated above...I went with the Crane Gold Adjustable rockers to see if the "Drive Me Up The Wall, Make Me Feel Like A Yugo" Ticking would go away...
It now sounds very quite...Just a slight mechanical sound, letting you know everything is working...Actually much quieter than the car was stock...
Try the rockers before swapping the cam out...Plus the added benefit of quick lift technology and less friction...You should see 10~15rwhp from the swap...
Peace...Gman
It now sounds very quite...Just a slight mechanical sound, letting you know everything is working...Actually much quieter than the car was stock...
Try the rockers before swapping the cam out...Plus the added benefit of quick lift technology and less friction...You should see 10~15rwhp from the swap...
Peace...Gman
Adjustable rockers or a pushrod change (length) will probably get you where you want, sounds like the preload is just a bit off. A Z06 cam with Z06 springs still makes a little valvetrain noise, but it's very mild (from driving a stock '01 Z06 a lot).
On The Tree
Joined: Sep 2004
Posts: 143
Likes: 0
From: St. Clair
That is correct...The factory rockers are non adjustable...The 22 ft.lbs. is simply the torque spec. that they want the bolts tightened too...With the factory rocker set up the amount of preload is determined by the rocker plate that the rockers bolt down on...The adjustable rockers sit on a post and all that holds them from falling down is the pushrod and the valve spring, so you can adjust the height via the adjusting nut lock screw...
Peace...Gman
Peace...Gman
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Originally Posted by under_construction
Adjustable rockers or a pushrod change (length) will probably get you where you want, sounds like the preload is just a bit off. A Z06 cam with Z06 springs still makes a little valvetrain noise, but it's very mild (from driving a stock '01 Z06 a lot).
