View Full Version : Valve train noise w/Comp Cam XE 268


TCSZ28
02-07-2007, 01:12:15 AM
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?

Cardinal
02-07-2007, 02:20:31 AM
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.

CWT Racin'
02-07-2007, 09:10:01 AM
You running rotella oil or some EOS?

pdq67
02-07-2007, 09:17:33 AM
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???

pdq67

ryork
02-07-2007, 09:43:36 AM
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.

67lemanster
02-07-2007, 10:06:09 AM
I have recently fired my rebuilt 350 running a Hydraulic Comp XE 268 cam. I have Vortec heads with stock self aligning rocker arms.


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

BIGBADBOWTIE
02-07-2007, 10:07:11 AM
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.

TCSZ28
02-07-2007, 11:01:46 AM
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. Itís not horrible, just louder than what I am used to

67lemanster
02-07-2007, 11:10:57 AM
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. Itís not horrible, just louder than what I am used to


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 :)

Marv D
02-07-2007, 11:20:44 AM
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.

Damon
02-07-2007, 01:37:01 PM
Also had noisy valves with the XE268. Repeated adjustments did nothing to quiet them down. Better lifters did nothing to quiet them down. I finally yanked it and put in something milder.

Found that only SOME of the noise was due to the aggressive nature of the XE cam. My lifter bores were slightly worn. If you put the lifter in and reached up inside the engine you could actually feel the lifter wiggle side-to-side a little at it's base. Up at the top of the lifter bore it was tight, but near the bottom of the bore it had worn enough that I got a little wiggle- similar to a worn valve guide.

Oh, and by the way, worn valve guides will also cause more valve clatter than fresh ones.

There's a bunch of places things can get noisy in a valvetrain. And aggressive cam will make all of them worse.

Darknight
02-07-2007, 01:46:43 PM
the 268 version of the voodoo compared to the 268xe is night and day. i put one in a car, not only was the unstable valve train assembly eliminated, but throttle response and torque and power where more even to 5800. shifted at 6100 and it worked good. i am considering the voodoo in my camaro when i change cams, i have a 268xe as well, but i am still debating going solid to get the most power out of my heads.
Doug Hubert (spelling?) makes great profile cams as well for street, and can grind one off with specs you like from different ones, or design one for you. For instance if you like a 230/234 duration and it has 110 center and you want a little more thump and top you can grind it it at 108-109. Very good friendly people, and Lunati makes great cams, the bracket master line, the voodoo line, and they have grinds similar to the Magnum lines of comp. Isky too. I have edelbrock heads with lightweight assemblies, so i dont expect as much wear on the train as some heads may be, but after watching it in action I dont think the super fast ramps are good for long term daily use when getting on it all the time. No matter what oil is run or how perfect your adjustments. I also did the ratio increase on both sides to up my pressure. The cam really woke up then, but I still believe my miss I have is more in that valvetrain than the electronics.
I cant rail them too much, its a good power cam with right set up, and good starting point, but..it does have its drawbacks. And for the record I run Harland Sharps as my rockers and they are pretty light and one of the quietest in my experience.

HULKZ28
02-07-2007, 10:53:34 PM
I ran an XE 274 in my 355 and it was very quiet.. I used the recommended 981 CC springs and crane alu. roller rockers..This cam did lose a lobe on the # 6 cyl. and was broke in with 30w non detergent oil and cam assy. lube(as per install instructions with cam).. It ran pretty well but didnt last 1000 milkes...
good luck
Hulk

pdq67
02-07-2007, 11:02:24 PM
Talk to UDHarold himself here!! He did the VooDoo line for Lunati's!!

"I work for Custom Camshaft Company, a division of Arrington Manufacturing.
I stay at my house in Senatobia, MS, and telecommute to work in Martinsville Va. My office phone is 662-301-1245, and so far I'm having to take my wife to work, she's a Staff Accountant in Memphis, so I'm not here before 9:00 AM CST or from 4:00 PM to 6:00 PM CST. I answer the phone when it rings, and have sold several cams to Team Chevelle members.

Harold"

And please say hello from pdq67 for me!!

pdq67

GoldenOne7710
02-07-2007, 11:06:02 PM
I run a XE274 and it's noisy as hell. It has been since day one and this motor is 2 1/2 years old. I've experienced NO mechanical issues due to the noise. My engine was build using brand new aftermarket heads and my lifter bores were trued and enlarged to accept Ford diameter lifters. The engine pulls very strong all the way to 6000 rpm. On the other hand, I assembled an engine for a friend using a XE284 and it was exceptionally quiet. I was quite surprised. Seems like more people comment on the XE268 & XE274 about noise than any other XE grinds.

jakeshoe
02-07-2007, 11:31:22 PM
IME,
Even the Magnum 270 and 280 grinds were a bit noisy. I've ran the 270 in a BBC and a SBC and it was particularly noisy in the SBC.

jim bean
02-07-2007, 11:43:08 PM
erased

450bench
02-07-2007, 11:48:25 PM
IMO, alot of Comp products are noisey...The roller tips are noisey as well...If you run Comp roller tips and a Comp grind, you can just about guarantee you'll be questionning yourself about doing something wrong

80ZED28 EH
02-08-2007, 12:52:21 AM
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 somebody 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.


I'd like to see that too. I have buddys that have run the XE series cams and have had nothing but problems with them i.e. wiped out lobes, lifters ruined, etc. etc... I think maybe CC's quality control has gone out the window. If and when I change cams, it will be a reeds, or an isky forsure. On another note I've been running a general kinetics cam for 10 yrs. that was designed by Harold, never a problem ever. i pulled it out of my old motor in my Nova, after 5 yrs. and it was like brand new still.........so I stabbed it in my Z-28 and that was almost 6 yrs. ago..........gotta like it.;)

Toomanyhobbys
02-08-2007, 11:32:51 AM
This is so wierd, I also have a 268, new Scoggins/Dickey Vortecs with the upgraded valve springs, and Comp magnum Rollers. Mine is very quiet??

Or I am old and getting deaf

andymiller
02-08-2007, 05:56:46 PM
My xe274 wan't bad at first, but now I really notice the noise. I just deal with it right now. But its starting to make me think its time for a change.

pdq67
02-08-2007, 10:12:57 PM
If I want a noisey valve train, I will run an older solid lifter cam like the old CC 282S and I put one in!!

pdq67

HULKZ28
02-08-2007, 10:28:46 PM
Yea, the noise of a solid is well worth the benefits that come with it!!
hulk

pdq67
02-08-2007, 10:33:03 PM
Ditto, Hulk!!

And the sound is natural so is fine to me....

pdq67