I just had a local race shop install a Comp XE294 hydraulic flat tappet cam and lifters in my 406. I used Howards Cams 98215 springs. They said it fired up fine and in 2 minutes rockers were clacking and the oil pressure dropped. I have 1.6 roller rockers and the springs are good for .600 lift. Not sure what caused the failure. I will be going to pick the car up tomorrow and hopefully they can tell me more.

 

It's not uncommon to wipe the lobes on a break -in. I've seen some early
wear on a couple lobes.

My quesiton is, what makes you think it's the lobe? It may be a loose locking
nut, or collapsed lifter?

Oil pressure dropping isn't related to the rockers. Put a dial on the lobe and
check the lifts.

 

I will know more tomorrow when I am able to get to the shop where my car is.

 

Did you lighten up the spring pressure on your springs for break in?

Might want to look at these http://www.schubeckracing.com/flatsolidframes.html

Bret

 

There's a lot of anecdotal evidence of people who have killed Comp Cams at break in. I just had my first cam death during break-in in 20 years of playing around with engines. Guess which cam? Comp Cams XE282 flat tappet. I got a bug up my butt and had the cam hardness tested becuase, like you, I couldn't find that I had done anything wrong with choice or parts, lubrication or proper break-in procedure, and I've installed more than just a couple of cams in my lifetime. The cam was WAY off the bottom end of the scale for hardness. It was a 25 when it should have been up over 50. It was doomed before I ever put it in the engine.

To the good: Comp replaced the cam and lifters under warranty (just on my say-so, not becuase I produced the testing results) and the replacement unit worked just fine with no problems.

I did use Comp's pain-in-the-butt procedure of removing the inner valve springs during break-in and then reinstalling them after break-in was complete on this second cam. However, Comp is the only company that seems to freak out about that and I don't recall ever doing something similar with cams from other companies and like I said, I never had a problem before.

 

I've seen a soft cam from Comp too. They do warranty the stuff when it happens. There is no way around it with flat tappet cams though, you have to use a cast core.

Bret

 

It's all about prep and following the instructions if you have any kind of spring pressure especially on the SBC. We've done huge flat tappets and still failed to ever wipe out a lobe in the last several years but it's very easy with any pressure on the more agressive lobes. This is on very agressive Comp and Ultradyne stuff too.

 

Well, I picked my car up yesterday and trailered it home. The shop says it ran for 10 minutes on the breakin then the clacking started and the oil pressure dropped. Other than than I don't know any details of their procedure. I do know I am out the cost of the cam, lifter, spring, labor, and I have a broken engine. If I had done this myself I would feel better but when a reputable speed shop does the install it sucks.

 

Was it a mechanical fuel pump? If the cam lobes get wiped out then yu should get that all under warranty.

Bret

 

It is an electric Holley Black fuel pump. I hope I get the cam and lifters replaced on warranty from Comp but the labor is gone and the cost of r and r ing the engine and rebuilding is mine now. They had one of the lifters out when I picked the car up. The gouging is all in a straight line so it doesn't look like the lifters were rotating at all.

 

I would think the shop would be at fault but I don't know the whole story so I will leave that alone. ALL lifters should be able to spin before you even put the valvetrain in on a flat tappet otherwise you will always flatten the lobe and wipe out the lifter. If they don't spin you fix that first before you go any further.

 

There are a couple of pics in this thread on thirdgen.

http://www.thirdgen.org/techbb2/show...hreadid=263543

 

Well, I sent the cam and lifters back to Comp and they replaced them under warranty. So that helped.

 

I lost 2 Nitrous HP 274 flat hyd/ cams last spring and I will never do anything but a roller again. Comp still hasn't gotten back to me with a "solution" or anything.

The first one I lost a lobe after about 300 miles and I was being really easy with the engine. The second I lost about 5 lobes just while breaking it in. I could tell because none of the lifters would stay adjusted, they just kept getting loose...Scrapped the engine which was just rebuilt, cyl walls scuffed and it was already .060+ with a touch hone...ah well it only ruined my whole spring/summer/fall's worth of racing/cruising/having fun, etc

That was supposed to be my backup engine...hahaha

 

I lost my Comp Cams XE262H. Lobes on cilinders # 6 and 8. They lasted nearly a whole summer, then died the next season. Go figure. I like Comp Cams, dont get me wrong, but after having a cam die like that, then hearing a story (first-hand) on an LT1 timing chain that was machined backwards, and then hearing a story (first hand) on a lifter that was missing the oil galley hole, followed by near-catostrophic valvetrain failure on a big dollar race engine makes it hard for me to maintain brand loyalty.

Comp blames my cam experience on high cam acceleration in the burnout box after idling in the stage lanes, which they think wiped the lubrication from the lobes. I don't know.... I've got a Comp hydraulic roller in the new engine and if I have any problems with it, I am switching cam manufacturers.