Hyd roller maybe. Solid roller will not last very long if you are running a real stiff cam. I will go solid roller someday but do it for HP not for longevity. Hyd roller should last the life of the engine. So should a cam for that matter if properly broken in. I have done many engines with various cams and never had a problem.

 

I have an XE cam and so do many other Forum members and agree with Gordonm, if properly installed and broken in you should not have any problems....

 

This seems to be sound advice. The XE's have aggressive ramp's, therefore are probably more prone to breakin problems, unless proper procedures are followed. I have managed to avoid such problems. Yet, with all of the talk of failures lately, on this forum and others, my next build will include a hyd. roller. Here's another string from this forum: http://forums.corvetteforum.com/show...268&forum_id=3

Good luck,
Kevin

 

There are physical limits to how close a designer can "pick up" the lifter. He can only get so close to the edge..usually around .013-.015 or so and have it live very long and not dig into the lifter and start eroding it away. The Mopar (.904 lifter) and Ford (.875) have advantages over us Chevy guys with our .842 lifters. They can design a more aggressive cam and have it live well in those motors.

Years ago there were "mushroom" lifters that were out around 1.00" diameter and were installed from the bottom of the motor before the cam was installed. It's pretty common even for roller cam guys to bore lifter bores out larger and use larger diameter lifters to increase longevity with killer cams. Every little bit helps. There are 1.00" roller lifters too.

Comp is pushing the design and are obviously having some issues. No doubt there are many out there running, but there does seem to be more issues with the X-treme line. Good name for them! When you push it....sometimes you get bit!

There are killer race type flat tappets with welded lobes that will make a 500 mile race. There have always been crazy race type flat tappets that last a few runs.

The Voodoo cams are doing the same thing, but differently. They "pick up" the lifter a little further back from the edge where they will live...then they accelerate it like crazy. Then there is the control issue as it slows down at peak lift...remember..it has to completely stop and change directions at the top of the lobe. You may have seen articles recently about the "Launcher" type of cams..they are designed to throw the lifter actually off the lobe at peak lift and achieve higher than "measured" lift in class racing. How long do you think that lives?

Anyway, after peak lift you have to accelerate the lifter again towards closing. They want to keep it open at peak lift as long as possible..that means it has to acclerate like crazy and slow down again at the bottom of the lobe. This is where Comp has the noise issue. They don't slow it down as much and the valves are noisy. Noise comes from the closing side primarily. The Voodoo's actually set the valve on the seat very near or even softer than stock GM stuff! To do that takes a pretty wild assymetrical lobe design where the opening side of lobe is completely different than the closing side...something many cams don't have. The more serious designed cams have done it for a gazzilion years..just takes mroe work. The guy who designed the Voodoos used to own Ultradyne....Harold Brookshire....was a serious player in the Hardcore race world. He now works at Lunati and has brought his ideas to the street market.

Comp makes good stuff for sure....but I have to ask....when picking a cam for the average street toy...do you want to push the envelope that far? I could easily use a much more aggressive roller cam in my 540...but I think I've got a 'softer" design that lives relatively well. Not sure the possibly added few HP is practical.

I think most folks would be better off concentrating on some other area of the motor to find the 5-10 hp than pushing the cam design to the limits. You'll never feel that amount of Hp and it will take a great dyno to see it. You'll have to have a really dialed in car to see it as a hundredth or two on a timeslip. Maybe work on using coatings? A little better port work? Valve jobs? Exhaust tweeks? Maybe different rocker ratios on intake and exhaust? Maybe a custom cam with lobes to compliment your heads and exhaust while still being able to live? All this stuff will add similar power gains more reliably.

I've had great luck with some roundy rounder flat tappets...they are pretty aggressive, but have to live too. Some "old tech" designs aren't quite as bad as marketing would lead you to believe. Often new designs are actually re-named old ones. I currently have an old Crane design flat tappet in my 540 for the summer and it's living just fine even with over .600 lift. "Tricker" ain't always better!


Otherwise, all the tips posted here are good. Direct oiling lifters (I'd use a HV pump to help low speed oil pressure) break in with outer springs, EOS and making sure it fires immediately are critical to making it live. At the first sign of any noise,,,STOP it and investigate. Trash all through the motor requires lots of work to clean up.


JIM

 

That sounds a little unfair to those who had an issue. What it sounds like you're saying is the person either improperly installed the cam or they did not follow the break-in procedure correctly. Either of these may not lead to cam failure but would only increase the chance of a lobe(s) prematurely wearing.
The simple fact is that the XE cam didn't break-in as anticipated. I'm sure some of these were not Comp's fault; however, there were some that were done correctly and failed. If I follow some of the logic that was presented here, most the people who do not know how to install/break-in the cam properly are somehow destined to buy a Comp Cam. I find that theory hard to believe. There is a reason why a larger percentage of XE cams fail. Some people just will not acknowledge it.

 

i am running an XE268H and have 2K miles on the rebuilt engine with out any difficulties....

 

With the latest round of oil leaks, valve adjustments, etc., done, I am still getting a horrible, almost lifter, almost rod knock, almost piston slap noise - generally from #2-#4 and lower down, particularly noticeable around 2300-2800 and WORSE when the oil pressure is HIGHER!. I don't detect wiped lobes as this thing moves all of them up hugely - I even measured them, but I can't rule out a lifter problem.

Until I change header gaskets to get rid of these annoying several exhaust leaks (you can even SEE them) I am basically driving it until it blows up, although with fear. (I cannot bring myself to believe those exhaust leaks are that sharp sounding....but I can HOPE!)

My vette shop listened to it while doing some emergency leak repairs and inspecting bearings and once seeing how badly the last idiot to work on it (not me! ) set the pushrod guideplates, told me to reset those and reset the lifters and try it. They thought it was not that monstrous a thing though - I sure do.

As a side note, I sure love the upgrade to the ProMag rockers....night and day over my cheapies.

 

I'm sure we'll never know all of the reasons why cams fail, and I'm surely not trying to be unfair or implicate a poor installation in this case or any other mentioned, but the fact is that some cams do get ruined by not following the Mfg's instructions. On the other hand can the mass manufactured cams and a gliche in quality control measures be possible?, yes, and like other Mfg's Comp has saturated the market. This could be another factor to explore in why we hear of more failures of Comp cams that others...I hate to see Forum members have problems with an engine they put alot of money and work into only to have a problem like this happen...

Bobs77vet: Nice meeting you at the show last Sunday Bob, and nice work you and your son are doing......

 

hey thanks, we had fun also ....we need to get you up north for a show....i'll keep you posted,bob

 

I've been following this endless discussion since I have the CC XE262H cam waiting to go in.....We are not the only ones: Hotrodders.com also has this one going. One thing I saw over there that I have not seen here concerns the lifter bores being square and true to the camshaft. It seems the big blocks have more of a problem with this than small blocks, but it sounds like something to consider.......
http://www.hotrodders.com/t64682.html&highlight=XE+cam
(I hope this works-I've never ever tried to send a "link" before) Anyway, here's one of their discussions. Lotsa good info here, even if a lot of these guys do drive magnetic cars with one-piece rear axles.
John

 

just for the record i don't buy the whole XE series is crap line....I'm gonna start keeping a record of people who have first hand knowledge of these failures...not antecdotal stories....i 've said it before and i'll say it again...too many variables, too many short cuts, mismatched parts, not broken in properly...yadda, yadda, yadda.....i do not dismiss the possibility of quality control issues and i'm not saying these people who installed them and had failures did anything wrong.....Counting the people in this post


80texasc3, did you actually see the cams? or did they just tell you this?

heres the failures...

money pit had a failure on one XE and success with another
steveg75 had two failures

any body else want to get on the list? My point is that when we actually list the failures of XE series i bet it will be small....

 

just for the record i don't buy the whole XE series is crap line....I'm gonna start keeping a record of people who have first hand knowledge of these failures...not antecdotal stories....i 've said it before and i'll say it again...too many variables, too many short cuts, mismatched parts, not broken in properly...yadda, yadda, yadda.....i do not dismiss the possibility of quality control issues and i'm not saying these people who installed them and had failures did anything wrong.....Counting the people in this post


heres the failures...

80texasc3...wiped two and installed a third one (he gets the brass ***** award )
73c34me..wiped one...what did you install the second time?
money pit had a failure on one XE and success with another
steveg75 had two failures

any body else want to get on the list? My point is that when we actually list the failures of XE series i bet it will be small....

 

Count me in for two of them... saw both... not good... had new 383 rebuilt (cleaned) after the second. May regret it...but there is a 3rd one in now...if it goes...I'm going roller.
Ed

 

got it thanks...edited previous post

 

Shop called this evening... I pick my car up tomorrow late afternoon. Am really looking forward to it but it will take some time before my confidence is up on the engine after these failures.

Temp in Dallas as been 100+... tomorrow is expected to be around 105. Hopefully the air conditioning still works...

 

good luck...i hope you have the same good luck the rest of us with XE series cams has had.

 

Bob - Should we count the non-wipes also to arrive at a rough percentage of failures to successes??

Brett

 

About every two months this issue comes up. Most of the time i`ll pass on this subject. But being in the auto parts business selling parts, building engines and also racing them. We have sold a countless number of camshafts and most of them are high reputation wild to mild nitro or gas performance cams. My point is that we have never experienced a bad lobe on a camshaft. You cannot cut corners and nearly all of them require several close tolerence checking points to install and also have to be adjusted correctly. Blaming the manufacturer might be a cop out

 

i bet the ratio of failures to successes will be really low....
i beleive there are two other guys that have posted having XE series failures....i need to find those threads to add to my list....so with the exception of those approximately 5 guys we are all happy....and its funny of those 5 guys at least two of them are still running XE series cams...you know with any product there could be random quality control issues that pop up and you can be sure if there is a cam problem there will be a 100% chance of it being noticed....i may even start a thread with a POLL on it if i can figure out how to do it...it is strange to me about the continual "chatter" on this from people who don't have the cams or have first hand knowledge of the product.

 

I can't remember if there has ever been a poll on this subject. Good idea!

Brett