XE cams = some valvetrain noise, see this....

Hmmm...I have the 274XE cam for about 4 years now and I have yet to hear such noise that you guys talk about.

Originally Posted by 82GT

Hmmm...I have the 274XE cam for about 4 years now and I have yet to hear such noise that you guys talk about.

I have the same problem. I can't hear my valvetrain either. I have solid lifters with more aggressive ramps (XTQ intakes and TL exhausts) than Comp XE cams. I also have 3-1/2 inch pipes, Dynomax Race Bullet mufflers and turndowns. I probably couldn't hear detonation if it were occuring. LOL!

paulie

Don't get me wrong. Mine only occurs at idle. When the engine revs, you can't hear it anymore. It's not that loud, but you can hear a slight metallic sound. It's just the nature of the cam. Iwantmore, who here built their hotrod to last 100k miles?? I'd say most of the time people are always tearing down their motor and playing with it anyway. I built mine with the intention to run 2500 miles a year or less. I sure I'll be building something different in the next 5 years.

Originally Posted by Bailey28

There is a reason I didn't go with the Comp series of XE cams.. I didn't like the valve train being beaten on a daily basis for a few more horsepower.

Comp seems to like very high lift, as I was looking at the XE258 and the 270HR, both at .533 and .544 lift. That seemed like a lot of lift for a daily driver.

I have my flame suit on, so I will go out on a limb and say that many engine builders (not all of course) will say that anything over .500 lift in a daily driver is eventually asking for trouble.

I will back up that claim. The man that helped me design my engine, and cut me a custom cam, (just under .500 lift) and builds sever duty Boat Engines. 302's were his favorite Detrot motor. He knows from fact that is the case. Remember Boat motors go to 5000 RPM's and stay at the speed for hours. He knows what wears a motor out and what is safe.

Isky #2 street/strip grind

.480/.500 lift, 210/218* at .050", 257/265 at .006" 112lsa

This is the cam that I am running in my 306. It is a roller cam, and using Harland Sharp 1.6 rockers, I get no real perceivable valvetrain noise.

If you compare the specs on this cam to comp's XE258HR, they are just about the same, all except comp's .533 and .544 lift.

.544? Daily driver? No thanks...

Comp XE266HR here, .545/.555 lift. No noise at idle or otherwise. From everything I read I was expecting some when I installed the cam.

Originally Posted by Spali32

Wanted to share some info I found.....for those of you that have experienced this sewing machine sound that doesn't want to go away


The XE or "extreme energy" cams are fast ramp cams that take maximum advantage of the lobe ramps that are possible with a hydraulic roller cam. This offers a power advantage over more milder lobe ramps. The XE cams will tend to make more noise than the milder ramp cams - this shouldn't be surprising to anybody. Because of the cams fast ramps, the cams will tend to sound like a solid lifter cam. If you look at the duration at .050 and then look at duration at .200 on Comp Xtreme energy cams and compare it to others, you realize that the comps have extremely fast lobes.

Comp Cams says that 'you will hear the valves open and close more'.

I'm confused...Your cam is a XE284H which is a flat tappet cam, but your talking about roller cams. Your cam is aggressive just the same, but if I had a hydraulic cam that sounded like a solid cam I would be worried. I'm assuming your lifter preload is set OK. Is your rocker geometry setup correctly?

Your cam may be making noise while others are not because the rockers your using are noisier than others...not a problem just a fact that some rockers are noisier than others. Another possible cause is that the pushrods are making contact with the holes in the heads as the valve reaches full lift...I had this problem once.

There are solid lifter profiles that will make that XE hydraulic profile look like the bunny slope...well almost. Hydraulic profiles only go so far before the inherent instability of the hydraulic design creates a limit. There are XE flat solid profiles that one won't find in the general Comp catalog and the profiles go up from there, but the spring rate and oiling provisions also increase. I'm not even talking about roller cam profiles which get even more aggressive.

Yes, but the XE cams in general whether hydraulic or roller cams have faster valvetrain motion than Comps previous cams. It may be my rocker arms being noisier. Everything was installed correctly as I remember.

Roller rockers should be a lot quieter. Think about it.