Valve train noise w/Comp Cam XE 268

Discussion in 'High Performance Modifications' started by TCSZ28, Feb 7, 2007.

  1. TCSZ28

    TCSZ28 Member

    Dec 31, 2003
    Wichita, Ks.
    I have recently fired my rebuilt 350 running a Hydraulic Comp XE 268 cam. I have Vortec heads with stock self aligning rocker arms. I have heard that the XE cams make a lot of valve train noise. My question is how do I determine how much noise is acceptable? When assembling the motor I set the valves twice just to make sure I had them right. The engine has less than an hour of run time on it but their sure is a noticeable amount of noise. My neighbor stopped by and asked my if I was running solid lifters (which is does make that type of sound). I will probably go through and set them again just to make sure since I am a little paranoid of them not being set right.
    What do you guys think?
  2. Cardinal

    Cardinal Veteran Member Lifetime Gold Member

    Jun 22, 2003
    Endicott, NY
    Hydraulic lifters should be quiet. Sounds like they aren't adjusted right.

    You should adjust them a total of 1/2 turn past zero lash. I like to adjust them with the engine running. Actually, I'm in the process of building a special cover to adjust them without the oilly mess. I have three built (plus my prototype). My cover eliminates the "the oil all over the place and running down on the hedders trying to catch on fire" mess.
  3. CWT Racin'

    CWT Racin' Veteran Member

    May 15, 2006
    You running rotella oil or some EOS?
  4. pdq67

    pdq67 BANNED

    Jul 26, 2001
    Columbia, MO, USA
    Yes, it should have some valvetrain noise b/c alotta the guys have bi-ched about the XE cam family on all the Boards in the past.

    But how much???

  5. ryork

    ryork Veteran Member

    Sep 7, 2000
    Indianapolis, IN
    I had a XE284 in a 355. I adjusted the valves 3 times all 1/2 turn past 0 lash (running) and it still sounded like a solid tappet cam. The cam was removed and sold..... It drove me crazy.

    I am currenty running two Voodoos - one in my truck (355) and the other in my Chevelle (406). I am very happy with both.
  6. 67lemanster

    67lemanster Veteran Member Lifetime Gold Member

    Oct 20, 2003
    I AM ILK

    did you break the cam in? you know 25 minutes at 2000rpm?

    BIGBADBOWTIE Veteran Member

    Dec 9, 2003
    Huntsville, Alabama
    Ditto to the above...... I just put one in a fresh 355 for my daily driver 86 c10. Its driving me nuts. It runs great but just has quite a bit of valvetrain noise.

    edit.. yes mine was fully broken in with Rotella and GM EOS.
  8. TCSZ28

    TCSZ28 Member

    Dec 31, 2003
    Wichita, Ks.
    Yes, I did break the cam in at 2500 and also running Rotella T and broke in with EOS as well. The initial firing and break in went fine.
    I will probably go ahead and re-adjust them again just to make sure and then live with the noise after that. It’s not horrible, just louder than what I am used to
  9. 67lemanster

    67lemanster Veteran Member Lifetime Gold Member

    Oct 20, 2003
    I AM ILK

    yep i had an xe 284 in my 383 its was loud. then i put in a a hydro roller that had less duration but a lot more lift. that pigs is also loud. sounds like your on top of it.

    we need vids...NOW :)
  10. Marv D

    Marv D Veteran Member Lifetime Gold Member

    The XE cams have very agressive ramps. The idea is to slam the valve open as quickly as possible to take advantage of the mid-lift flow. The hydraulic lifters limit the valve spring rate and the springs that are recomended are too light to control a heavy valve, retainer, rocker and pushrod. What your hearing is slack coming in the valve train as the lifter it tossed over the crown of the lobe. IMO it's a VERY poor design,,, but people keep buying them and Comp keeps selling them. If you want to quiet an XE cam down, you have a couple of options.

    A 2.02 or 2.08" valve offers great flow, but is a heavy valve, especially if it's a stainless street valve. Use the lightest valve you can afford.

    Titanium retainers and locks,,, again keeping valve train weight down as much as possible.

    Light weight rockers (be carefull, not all aluminum roller rockers are created equal, not in just quality, but in weight also) Do you homework before just ordering up a set of aluminum roller rockers. Some are MUCH heavier than stock!

    Higher ratio rockers sometimes bandaid the weak spring syndrome. By increasing the rocker ratio, you effectively increase the spring pressure seen on the pushrod side of the rocker. BUT, because the travel of the pushrod is not changed, but the distance the valve has to travel is increased (over the same time of the given stroke) you can move the clacking from one side of the rocker to the other.

    I have no idea of the physics involved, but when larger diameter springs are used, you seem to have better valve control even with similar spring rates. The 'beehive' springs seem to be gaining popularity for this very reason. Worth looking in to.

    Or,,,, you can do like many that have already replied,, throw the XE POS as far as you can, and look into an Isky, Crower, Lunati or other cam that isn't so harsh on the valve train.

    I would love to see back to back dyno pulls with a XE grind, and one of near similar specs from Crower or Lunati (from some body other than a paid advertiser in one of the cr rags). I'd bet there is some midrange torque benifits from the agressive XE, but I bet peak power is not that much different.

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