Well, I am sure some of you guys read my post about a tick in engine or knocking fuel pump. I replaced the pump and still had this knock or tick that made the noise with every revolution of the cam. Well I finally pulled my intake off to look. TO recap I just recently built this engine. Its a 383 small block. I clearanced the block and I clearanced the rods to clear the cam. I have put on about 200 miles. My cam is a comp XE274 flat tappet hyd. I found the #4 exhaust lifter worn abnormal. The lobe, and its still there has a funny wear pattern. The lifter is worn on the outside of the face. The face is very convex. I realize they will not be completely flat but any lifter I have seen that was cooked was concaved like a canoe and would wipe the lobe off. I also found that the chrome they use on the face and side of the lifter is chipped at the edges of the face. WTF!!! Myself as well as my friends have not seen a lifter wear like this before. The rest of the lifters look ok as well as the rest of the lobes and their wear patterns. I dont know what could have caused this. Breakin in the engine went excellent with no hiccups. Valves were all adjusted properly. This isnt the first engine build or cam swap. It was all straight forward. What do you guys think would cause a lifter to wear like this? Or would a defective cam cause a lifter to wear like this? Any input would be greatly appreciated.

this brings to mind a lengthy disertation I read here a month or 2 ago, I think by Gary in New York (gosfast??) Regarding how core shift can affect lifter to cam alignment, and how to check and correct it... Basically brought up the possibility of the cam being to far forward or back and not aligning with the lifters correctly. Kinda rings a bell here.

I had a comp magnum 292 in the motor for a long time without any problems before I decided to stroke it. I wouldnt think a problem like this would arise after a rebuild. At least I hope not. Something to think about for sure thanks.

Sorry to hear of your misfortune,..

From that cam, I'm not surprised you wiped an exhaust lobe. I'm more than convinced that the exhaust ramp on the XE line of cams is too aggressive. It breaks the rules regarding duration/lift. The intake ramps on this cam are easier on the valve train,..and it's the same lobes used on Comp's Magnum line,..with which you seldom hear of problems.

Another possibilty, is, if the lifter doesn't spin freely in it's bore, it will wipe a lobe,..so when installing lifters, make sure it's not too tight in the bore, and make sure the bores, lifters, and lube are clean.

My opinion...

The lifter was spinning in the bore. I think this may be why the lifter wore on the edges causing it to wear convex as opposed to concaved. The lobe is still there although I have not measure the exact dimensions.

if the lifter is bad, the lobe is too....

Yes,..Jim's right,..you'll have to replace both the cam and lifters (all 16 would be smart).

The good news is, it doesn't sound like a lot of lifter and lobe "shavings" are in your engine.

Your intake is already off,..so sliding another cam in won't be much more work...but not what you had in mind either. We're with you!

Good luck!

Lifter spin is necessary. My only other thought is how the rear cam plug was installed thus keeping the cam too far forward or rearward ? But this is usually fool proof? Most likely the lifter bore was tight and did not allow the lifter to spin. Just curious on what the lobe looks like? How bad it it? Could a new lifter live? Do you want to try? Just some input here . I would definately check the fit on a new lifter on that bore and if you have a pair of snap guages, mike them both and see if they are within tolerances, You may be dealing with a block issue or resleeve a lifter bore if its too loose and was cocked in bore??

the cam doesn't (or better not) bear on the rear plug. The thrust surface for the cam is machined into the front of the block and the backside of the timing gear. natural rotation will push the cam backwards against the thrust surface. I suppose it's possible for the plug to be in too deep and hold the cam forward but that would be bad.

Just so none of you guys think I am trying to get an easy way out I will say that I am DEFINITELY going to change both the cam and lifters. LOL. THere is no way I am going to chance either of these parts. If it was a typical cam/lifter wipe out I wouldnt even post this but this one seems very odd to me. The lobe looks centered when you look down the bore of the lifter. Strange

Compare lifter bores , if you have some snap gauges that would be better. While you got it out ,, take a brite flash lite and check the spin marks on the rear cam plug. Just a thought.

scotty,i p/m'ed you before i read your post.sorry to hear about the cam!making me think twice about puttin the xe274 in the 383!
Eric B